Dementia
Overview
Dementia is a serious loss of cognitive
Cognition
In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...

 ability in a previously unimpaired person, beyond what might be expected from normal aging
Ageing
Ageing or aging is the accumulation of changes in a person over time. Ageing in humans refers to a multidimensional process of physical, psychological, and social change. Some dimensions of ageing grow and expand over time, while others decline...

. It may be static, the result of a unique global brain injury
Brain injury
A brain injury is any injury occurring in the brain of a living organism. Brain injuries can be classified along several dimensions. Primary and secondary brain injury are ways to classify the injury processes that occur in brain injury, while focal and diffuse brain injury are ways to classify...

, or progressive, resulting in long-term decline due to damage or disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...

 in the body. Although dementia is far more common in the geriatric
Geriatrics
Geriatrics is a sub-specialty of internal medicine and family medicine that focuses on health care of elderly people. It aims to promote health by preventing and treating diseases and disabilities in older adults. There is no set age at which patients may be under the care of a geriatrician, or...

 population, it can occur before the age of 65, in which case it is termed "early onset dementia".

Dementia is not a single disease, but rather a non-specific illness syndrome
Syndrome
In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...

 (i.e., set of signs and symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

s) in which affected areas of cognition may be memory
Memory
In psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....

, attention
Attention
Attention is the cognitive process of paying attention to one aspect of the environment while ignoring others. Attention is one of the most intensely studied topics within psychology and cognitive neuroscience....

, language
Language
Language may refer either to the specifically human capacity for acquiring and using complex systems of communication, or to a specific instance of such a system of complex communication...

, and problem solving
Problem solving
Problem solving is a mental process and is part of the larger problem process that includes problem finding and problem shaping. Consideredthe most complex of all intellectual functions, problem solving has been defined as higher-order cognitive process that requires the modulation and control of...

.
Encyclopedia
Dementia is a serious loss of cognitive
Cognition
In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...

 ability in a previously unimpaired person, beyond what might be expected from normal aging
Ageing
Ageing or aging is the accumulation of changes in a person over time. Ageing in humans refers to a multidimensional process of physical, psychological, and social change. Some dimensions of ageing grow and expand over time, while others decline...

. It may be static, the result of a unique global brain injury
Brain injury
A brain injury is any injury occurring in the brain of a living organism. Brain injuries can be classified along several dimensions. Primary and secondary brain injury are ways to classify the injury processes that occur in brain injury, while focal and diffuse brain injury are ways to classify...

, or progressive, resulting in long-term decline due to damage or disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...

 in the body. Although dementia is far more common in the geriatric
Geriatrics
Geriatrics is a sub-specialty of internal medicine and family medicine that focuses on health care of elderly people. It aims to promote health by preventing and treating diseases and disabilities in older adults. There is no set age at which patients may be under the care of a geriatrician, or...

 population, it can occur before the age of 65, in which case it is termed "early onset dementia".

Dementia is not a single disease, but rather a non-specific illness syndrome
Syndrome
In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...

 (i.e., set of signs and symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

s) in which affected areas of cognition may be memory
Memory
In psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....

, attention
Attention
Attention is the cognitive process of paying attention to one aspect of the environment while ignoring others. Attention is one of the most intensely studied topics within psychology and cognitive neuroscience....

, language
Language
Language may refer either to the specifically human capacity for acquiring and using complex systems of communication, or to a specific instance of such a system of complex communication...

, and problem solving
Problem solving
Problem solving is a mental process and is part of the larger problem process that includes problem finding and problem shaping. Consideredthe most complex of all intellectual functions, problem solving has been defined as higher-order cognitive process that requires the modulation and control of...

. It is normally required to be present for at least 6 months to be diagnosed; cognitive dysfunction that has been seen only over shorter times, in particular less than weeks, must be termed delirium
Delirium
Delirium or acute confusional state is a common and severe neuropsychiatric syndrome with core features of acute onset and fluctuating course, attentional deficits and generalized severe disorganization of behavior...

. In all types of general cognitive dysfunction, higher mental functions are affected first in the process.

Especially in the later stages of the condition, affected persons may be disoriented in time (not knowing what day of the week, day of the month, or even what year it is), in place (not knowing where they are), and in person (not knowing who they, or others around them, are). Dementia, though often treatable to some degree, is usually due to causes that are progressive and incurable.

Symptoms of dementia can be classified as either reversible or irreversible, depending upon the etiology
Etiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....

 of the disease. Less than 10% of cases of dementia are due to causes that may presently be reversed with treatment. Causes include many different specific disease processes, in the same way that symptoms of organ dysfunction such as shortness of breath, jaundice
Jaundice
Jaundice is a yellowish pigmentation of the skin, the conjunctival membranes over the sclerae , and other mucous membranes caused by hyperbilirubinemia . This hyperbilirubinemia subsequently causes increased levels of bilirubin in the extracellular fluid...

, or pain
Pain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...

 are attributable to many etiologies.

Without careful assessment of history, the short-term syndrome of delirium (often lasting days to weeks) can easily be confused with dementia, because they have all symptoms in common, save duration. Some mental illnesses, including depression
Depression (mood)
Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...

 and psychosis
Psychosis
Psychosis means abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality"...

, may produce symptoms that must be differentiated from both delirium and dementia.

There are many specific types (causes) of dementia, often showing slightly different symptoms. However, the symptom overlap is such that it is impossible to diagnose the type of dementia by symptomatology alone, and in only a few cases are symptoms enough to give a high probability of some specific cause. Diagnosis is therefore aided by nuclear medicine
Nuclear medicine
In nuclear medicine procedures, elemental radionuclides are combined with other elements to form chemical compounds, or else combined with existing pharmaceutical compounds, to form radiopharmaceuticals. These radiopharmaceuticals, once administered to the patient, can localize to specific organs...

 brain scanning
Neuroimaging
Neuroimaging includes the use of various techniques to either directly or indirectly image the structure, function/pharmacology of the brain...

 techniques. Certainty cannot be attained except with brain biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...

 during life, or at necropsy
Autopsy
An autopsy—also known as a post-mortem examination, necropsy , autopsia cadaverum, or obduction—is a highly specialized surgical procedure that consists of a thorough examination of a corpse to determine the cause and manner of death and to evaluate any disease or injury that may be present...

 in death.

Some of the most common forms of dementia are: Alzheimer's disease
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...

, vascular dementia
Multi-infarct dementia
Multi-infarct dementia is one type of vascular dementia. Vascular dementia is the second most common form of dementia after Alzheimer's disease in older adults. Multi-infarct dementia is thought to be an irreversible form of dementia, and its onset is caused by a number of small strokes or...

, frontotemporal dementia
Frontotemporal dementia
Frontotemporal dementia is a clinical syndrome caused by degeneration of the frontal lobe of the brain and may extend back to the temporal lobe...

, semantic dementia
Semantic dementia
Semantic dementia is a progressive neurodegenerative disorder characterized by loss of semantic memory in both the verbal and non-verbal domains...

 and dementia with Lewy bodies
Dementia with Lewy bodies
Dementia with Lewy bodies , also known under a variety of other names including Lewy body dementia, diffuse Lewy body disease, cortical Lewy body disease, and senile dementia of Lewy type, is a type of dementia closely allied to both Alzheimers and Parkinson's Diseases...

. It is possible for a patient to exhibit two or more dementing processes at the same time, as none of the known types of dementia protects against the others.

History

Up to the end of the 19th century, dementia was a much broader clinical concept, which included mental illness and any type of psychosocial incapacity, including those which could be reversed. Dementia at this time simply referred to anyone who had lost the ability to reason, and was applied equally to psychosis of mental illness, "organic" diseases like syphilis
Syphilis
Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis...

 which could destroy the brain, and to the dementia associated with old age, which was held to be caused by "hardening of the arteries."

Dementia when seen in the elderly was called senile dementia or senility and viewed as a normal and somewhat inevitable aspect of growing old, rather than as being caused by any specific diseases. At the same time, in 1907, a specific organic dementing process of early onset, called Alzheimer's disease
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...

, had been described. This was associated with particular microscopic changes in the brain, but was seen as a rare disease of middle age.

Much like other diseases associated with aging, dementia was rare before the 20th century, although by no means unknown, due to the fact that people seldom lived long enough to experience it.

By the period of 1913-20, schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...

 had been well-defined in a way similar to today, and also the term dementia praecox
Dementia praecox
Dementia praecox refers to a chronic, deteriorating psychotic disorder characterized by rapid cognitive disintegration, usually beginning in the late teens or early adulthood. It is a term first used in 1891 in this Latin form by Arnold Pick , a professor of psychiatry at the German branch of...

 had been used to suggest the development of senile-type dementia at a younger age. Eventually the two terms fused, so that until 1952 physicians used the terms dementia praecox
Dementia praecox
Dementia praecox refers to a chronic, deteriorating psychotic disorder characterized by rapid cognitive disintegration, usually beginning in the late teens or early adulthood. It is a term first used in 1891 in this Latin form by Arnold Pick , a professor of psychiatry at the German branch of...

 ("precocious dementia") and schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...

 interchangeably. The term "precocious dementia" for a mental illness suggested that a type of mental illness like schizophrenia (including paranoia and decreased cognitive capacity) could be expected to arrive normally in all persons with greater age (see paraphrenia
Paraphrenia
Paraphrenia is described as a group of psychotic illnesses distinct from paranoia and from schizophrenia.. Paraphrenia as a separate disorder is not included in either ICD 10 or DSM IV and is likely to be classified as atypical psychosis, schizoaffective disorder or delusional disorder using these...

). At the same time, the beginning use of dementia to describe both what we know understand as schizophrenia and senile dementia, after about 1920, acted to give the word "dementia" a more limited role, as one of describing a type of permanent mental deterioration which was not expected to be reversible. This is the beginning of the more recognizable use of the term today.

In 1976, neurologist Robert Katzmann suggested a link between "senile dementia" and Alzheimer's disease. Katzmann suggested that much of the senile dementia occurring (by definition) after the age of 65, was pathologically identical with Alzheimer's disease occurring before age 65 and therefore should not be treated differently. He noted that the fact the "senile dementia" was not considered a disease, but rather part of aging, and this fact was keeping millions of aged patients with what otherwise was identical with Alzheimer's disease, from being diagnosed as having a disease process, rather than simply considered as aging normally. Katzmann thus suggested that Alzheimer's disease, if taken to occur over age 65, is actually common, not rare, and was the 4th or 5th leading cause of death, even though rarely being reported on death certificates in 1976.

This suggestion opened the view that dementia is never normal, and must always be the result of a particular disease process, and is not part of the normal healthy aging process, per se. The ensuing debate led for a time to the proposed disease diagnosis of "senile dementia of the Alzheimer's type" (SDAT) in persons over the age of 65, with "Alzheimer's disease" diagnosed in persons younger than 65 who had the same pathology. Eventually, however, it was agreed that the age limit was artificial, and that Alzheimer's disease was the appropriate term for persons with the particular brain pathology seen in this disease, regardless of the age of the sufferer. A helpful finding was that although the incidence of Alzheimer's disease increased with age (from 5-10% of 75-year-olds to as many as 40-50% of 90-year-olds), there was no age at which all persons developed it, so it was not an inevitable consequence of aging, no matter how great an age a person attained.

Also, after 1952, mental illnesses like schizophrenia were removed from the category of "organic brain syndrome
Organic Brain Syndrome
Organic brain syndrome , also known as organic brain disease or organic brain disorder, is an older and nearly obsolete general term from psychiatry, referring to many physical disorders that cause impaired mental function. It usually does not include psychiatric disorders...

s," and thus (by definition) removed from possible causes of "dementing illnesses" (dementias). At the same, however, the traditional cause of senile dementia – "hardening of the arteries" – now returned as a set of dementias of vascular cause (small strokes). These were now termed "multi-infarct dementias" or vascular dementias.

In the 21st century, a number of other types of dementia have been differentiated from Alzheimer's disease and vascular dementias (these two being the most common types). This differentiation is on the basis of pathological examination of brain tissues, symptomatology, and by different patterns of brain metabolic activity in nuclear medical imaging tests such as SPECT and PET
Positron emission tomography
Positron emission tomography is nuclear medicine imaging technique that produces a three-dimensional image or picture of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide , which is introduced into the body on a...

 scans of the brain. The various forms of dementia have differing prognoses (expected outcome of illness), and also differing sets of epidemologic risk factors. The causal etiology of many of them, including Alzheimer's disease, remains unknown, although many theories exist such as accumulation of protein plaques as part of normal aging, inflammation, inadequate blood sugar, and traumatic brain injury.

Comorbidities

Dementia is not merely a problem of memory. It reduces the ability to learn, reason, retain or recall past experience and there is also loss of patterns of thoughts, feelings and activities (Gelder et al. 2005). Additional mental and behavioral problems often affect people who have dementia, and may influence quality of life, caregivers, and the need for institutionalization. As dementia worsens individuals may neglect themselves and may become disinhibited and may become incontinent. (Gelder et al. 2005).

Depression affects 20–30% of people who have dementia, and about 20% have anxiety. Psychosis (often delusions of persecution) and agitation/aggression also often accompany dementia. Each of these needs to be assessed and treated independent of the underlying dementia.

Risk to self and others

The Canadian Medical Association Journal has reported that driving
Driving
Driving is the controlled operation and movement of a land vehicle, such as a car, truck or bus.Although direct operation of a bicycle and a mounted animal are commonly referred to as riding, such operators are legally considered drivers and are required to obey the rules of the road...

 with dementia could lead to severe injury or even death to self and others. Doctors should advise appropriate testing on when to quit driving.

In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, Florida's Baker Act allows law enforcement and the judiciary to force mental evaluation for those suspected of suffering from dementia or other mental incapacities.

In the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, as with all mental disorders, where a sufferer could potentially be a danger to themselves or others, they can be detained under the Mental Health Act of 1983 for the purposes of assessment, care and treatment. This is a last resort, and usually avoided if the patient has family or friends who can ensure care.

The United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 DVLA (Driving & Vehicle Licensing Agency) states that dementia sufferers who specifically suffer with poor short term memory, disorientation, lack of insight or judgment are almost certainly not fit to drive—and in these instances, the DVLA must be informed so said license can be revoked. They do however acknowledge low-severity cases and early sufferers, and those drivers may be permitted to drive pending medical reports.

Behaviour may be disorganized, restless or inappropriate. Some people become restless or wander about by day and sometimes at night. When people suffering from dementia are put in circumstances beyond their abilities, there may be a sudden change to tears or anger (a "catastrophic reaction").

Fixed cognitive impairment

Various types of brain injury, occurring as a single event, may cause irreversible but fixed cognitive impairment. Traumatic brain injury
Traumatic brain injury
Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...

 may cause generalized damage to the white matter of the brain (diffuse axonal injury
Diffuse axonal injury
Diffuse axonal injury is one of the most common and devastating types of traumatic brain injury, meaning that damage occurs over a more widespread area than in focal brain injury. DAI, which refers to extensive lesions in white matter tracts, is one of the major causes of unconsciousness and...

), or more localized damage (as also may neurosurgery
Neurosurgery
Neurosurgery is the medical specialty concerned with the prevention, diagnosis, treatment, and rehabilitation of disorders which affect any portion of the nervous system including the brain, spine, spinal cord, peripheral nerves, and extra-cranial cerebrovascular system.-In the United States:In...

). A temporary reduction in the brain's supply of blood or oxygen may lead to hypoxic-ischemic injury
Cerebral hypoxia
Cerebral hypoxia refers to a reduced supply of oxygen to the brain. Cerebral anoxia refers to a complete lack of oxygen to the brain. There are four separate categories of cerebral hypoxia; in order of severity they are; diffuse cerebral hypoxia , focal cerebral ischemia, cerebral infarction, and...

. Stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...

s (ischemic stroke, or intracerebral, subarachnoid, subdural or extradural hemorrhage) or infections (meningitis
Meningitis
Meningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs...

 and/or encephalitis
Encephalitis
Encephalitis is an acute inflammation of the brain. Encephalitis with meningitis is known as meningoencephalitis. Symptoms include headache, fever, confusion, drowsiness, and fatigue...

) affecting the brain, prolonged epileptic seizure
Seizure
An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...

s and acute hydrocephalus
Hydrocephalus
Hydrocephalus , also known as "water in the brain," is a medical condition in which there is an abnormal accumulation of cerebrospinal fluid in the ventricles, or cavities, of the brain. This may cause increased intracranial pressure inside the skull and progressive enlargement of the head,...

 may also have long-term effects on cognition. Excessive alcohol use may cause alcohol dementia
Alcohol dementia
Alcohol dementia, which is sometimes associated with Wernicke-Korsakoff syndrome, is a form of dementia caused by long-term or excessive drinking resulting in neurological damage and memory loss. Other names for the condition are alcoholic dementia, alcohol related dementia and alcohol-induced...

, Wernicke's encephalopathy
Wernicke's encephalopathy
Wernicke encephalopathy is a syndrome characterised by ataxia, ophthalmoplegia, confusion, and impairment of short-term memory.It is caused by lesions in the medial thalamic nuclei, mammillary bodies, periaqueductal and periventricular brainstem nuclei, and superior cerebellar vermis, often...

 and/or Korsakoff's psychosis, and certain other recreational drugs may cause substance-induced persisting dementia; once overuse ceases, the cognitive impairment is persistent but not progressive.

Slowly progressive dementia

Dementia which begins gradually and worsens progressively over several years is usually caused by neurodegenerative disease; that is, by conditions affecting only or primarily the neurons of the brain and causing gradual but irreversible loss of function of these cells. Less commonly, a non-degenerative condition may have secondary effects on brain cells, which may or may not be reversible if the condition is treated.

The causes of dementia depend on the age at which symptoms begin. In the elderly population (usually defined in this context as over 65 years of age), a large majority of cases of dementia are caused by Alzheimer's disease
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...

, vascular dementia or both. Dementia with Lewy bodies
Dementia with Lewy bodies
Dementia with Lewy bodies , also known under a variety of other names including Lewy body dementia, diffuse Lewy body disease, cortical Lewy body disease, and senile dementia of Lewy type, is a type of dementia closely allied to both Alzheimers and Parkinson's Diseases...

 is another fairly common cause, which again may occur alongside either or both of the other causes. Hypothyroidism
Hypothyroidism
Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...

 sometimes causes slowly progressive cognitive impairment as the main symptom, and this may be fully reversible with treatment. Normal pressure hydrocephalus
Normal pressure hydrocephalus
Normal pressure hydrocephalus , also termed symptomatic hydrocephalus, occurs when there is an increase in intracranial pressure due to an abnormal accumulation of cerebrospinal fluid in the ventricles of the brain, which can cause ventriculomegaly...

, though relatively rare, is important to recognize since treatment may prevent progression and improve other symptoms of the condition. However, significant cognitive improvement is unusual.

Dementia is much less common under 65 years of age. Alzheimer's disease is still the most frequent cause, but inherited forms of the disease account for a higher proportion of cases in this age group. Frontotemporal lobar degeneration
Frontotemporal lobar degeneration
-Further reading:*Hodges, John R. The Frontotemporal Dementia Syndromes. Cambridge University Press. 2007 ISBN 978-0-521-85477-1-External links:****Mayo Clinic - **...

 and Huntington's disease
Huntington's disease
Huntington's disease, chorea, or disorder , is a neurodegenerative genetic disorder that affects muscle coordination and leads to cognitive decline and dementia. It typically becomes noticeable in middle age. HD is the most common genetic cause of abnormal involuntary writhing movements called chorea...

 account for most of the remaining cases. Vascular dementia also occurs, but this in turn may be due to underlying conditions (including antiphospholipid syndrome
Antiphospholipid syndrome
Antiphospholipid syndrome or antiphospholipid antibody syndrome , often also Hughes syndrome, is an autoimmune, hypercoagulable state caused by antibodies against cell-membrane phospholipids that provokes blood clots in both arteries and veins as well as pregnancy-related complications such as...

, CADASIL
CADASIL
CADASIL is the most common form of hereditary stroke disorder, and is thought to be caused by mutations of the Notch 3 gene on chromosome 19. The disease belongs to a family of disorders called the Leukodystrophies...

, MELAS
MELAS
Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes – abbreviated to MELAS – is one of the family of mitochondrial cytopathies, which also include MERRF, and Leber's hereditary optic neuropathy. It was first characterized under this name in 1984...

, homocystinuria
Homocystinuria
Homocystinuria, also known as cystathionine beta synthase deficiency or CBS deficiency, is an inherited disorder of the metabolism of the amino acid methionine, often involving cystathionine beta synthase...

, moyamoya and Binswanger's disease
Binswanger's disease
Binswanger's disease is a form of small vessel vascular dementia caused by damage to the white brain matter. White matter atrophy can be caused by many circumstances including chronic hypertension as well as old age. This disease is characterized by loss of memory and intellectual function and by...

). People who receive frequent head trauma, such as boxers or football players, are at risk of chronic traumatic encephalopathy
Chronic traumatic encephalopathy
Chronic traumatic encephalopathy is a progressive degenerative disease found in individuals who have been subjected to multiple concussions and other forms of head injury. A variant of the condition, dementia pugilistica, is primarily associated with boxing...

 (also called dementia pugilistica
Dementia pugilistica
Dementia pugilistica is a type of neurodegenerative disease or dementia, which may affect amateur or professional boxers as well as athletes in other sports who suffer concussions...

 in boxers).

In young adults (up to 40 years of age) who were previously of normal intelligence, it is very rare to develop dementia without other features of neurological disease, or without features of disease elsewhere in the body. Most cases of progressive cognitive disturbance in this age group are caused by psychiatric illness, alcohol or other drugs, or metabolic disturbance. However, certain genetic disorders can cause true neurodegenerative dementia at this age. These include familial Alzheimer's disease
Early-onset Alzheimer's disease
Early-onset Alzheimer's disease, also called early-onset Alzheimer's, or early-onset AD, is the term used for cases of Alzheimer's disease diagnosed before the age of 65. It is an uncommon form of Alzheimer's, accounting for only 5-10% of all Alzheimer's sufferers...

, SCA17
Spinocerebellar ataxia
Spinocerebellar ataxia is a progressive, degenerative, genetic disease with multiple types, each of which could be considered a disease in its own right.-Classification:...

 (dominant inheritance); adrenoleukodystrophy
Adrenoleukodystrophy
Adrenoleukodystrophy is a rare, inherited disorder that leads to progressive brain damage, failure of the adrenal glands and eventually death. ALD is a disease in a group of genetic disorders called leukodystrophies, whose chief feature is damage to myelin...

 (X-linked
Sex linkage
Sex linkage is the phenotypic expression of an allele related to the chromosomal sex of the individual. This mode of inheritance is in contrast to the inheritance of traits on autosomal chromosomes, where both sexes have the same probability of inheritance...

); Gaucher's disease
Gaucher's disease
Gaucher's disease is a genetic disease in which a fatty substance accumulates in cells and certain organs.Gaucher's disease is the most common of the lysosomal storage diseases. It is caused by a hereditary deficiency of the enzyme glucosylceramidase. The enzyme acts on the fatty acid...

 type 3, metachromatic leukodystrophy
Metachromatic leukodystrophy
Metachromatic leukodystrophy is a lysosomal storage disease which is commonly listed in the family of leukodystrophies. Leukodystrophies affect the growth and/or development of myelin, the fatty covering which acts as an insulator around nerve fibers throughout the central and peripheral nervous...

, Niemann-Pick disease type C, pantothenate kinase-associated neurodegeneration
Pantothenate kinase-associated neurodegeneration
Pantothenate kinase-associated neurodegeneration , also known as neurodegeneration with brain iron accumulation 1 and formerly called Hallervorden-Spatz syndrome Pantothenate kinase-associated neurodegeneration (PKAN), also known as neurodegeneration with brain iron accumulation 1 (NBIA1) and...

, Tay-Sachs disease
Tay-Sachs disease
Tay–Sachs disease is an autosomal recessive genetic disorder...

 and Wilson's disease
Wilson's disease
Wilson's disease or hepatolenticular degeneration is an autosomal recessive genetic disorder in which copper accumulates in tissues; this manifests as neurological or psychiatric symptoms and liver disease...

 (all recessive). Wilson's disease is particularly important since cognition can improve with treatment.

At all ages, a substantial proportion of patients who complain of memory difficulty or other cognitive symptoms are suffering from depression rather than a neurodegenerative disease. Vitamin deficiencies and chronic infections may also occur at any age; they usually cause other symptoms before dementia occurs, but occasionally mimic degenerative dementia. These include deficiencies of vitamin B12
Vitamin B12 deficiency
Vitamin B12 deficiency or hypocobalaminemia is a low blood level of vitamin B12, it can cause permanent damage to nervous tissue as a long term effect. Vitamin B12 was discovered from its relationship to the disease pernicious anemia, which is an autoimmune disease that destroys parietal cells in...

, folate
Folate deficiency
Folate deficiency is a lack of folic acid in the diet and the signs are often subtle. Folate deficiency anemia is the medical name given for the condition. -Symptoms:Loss of appetite, and weight loss can occur...

 or niacin
Pellagra
Pellagra is a vitamin deficiency disease most commonly caused by a chronic lack of niacin in the diet. It can be caused by decreased intake of niacin or tryptophan, and possibly by excessive intake of leucine. It may also result from alterations in protein metabolism in disorders such as carcinoid...

, and infective causes including cryptococcal meningitis, HIV
AIDS dementia complex
AIDS dementia complex is a common neurological disorder associated with HIV infection and AIDS. It is a metabolic encephalopathy induced by HIV infection and fueled by immune activation of brain macrophages and microglia...

, Lyme disease
Lyme disease
Lyme disease, or Lyme borreliosis, is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Borrelia burgdorferi sensu stricto is the main cause of Lyme disease in the United States, whereas Borrelia afzelii and Borrelia garinii cause most...

, progressive multifocal leukoencephalopathy
Progressive multifocal leukoencephalopathy
Progressive multifocal leukoencephalopathy , also known as progressive multifocal leukoencephalitis, is a rare and usually fatal viral disease that is characterized by progressive damage or inflammation of the white matter of the brain at multiple locations .It occurs almost exclusively in...

, subacute sclerosing panencephalitis
Subacute sclerosing panencephalitis
Subacute sclerosing panencephalitis is a rare chronic, progressive encephalitis that affects primarily children and young adults, caused by a persistent infection of immune resistant measles virus . No cure for SSPE exists, but the condition can be managed by medication if treatment is started at...

, syphilis
Syphilis
Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis...

 and Whipple's disease
Whipple's disease
Whipple's disease is a rare, systemic infectious disease caused by the bacterium Tropheryma whipplei. First described by George Hoyt Whipple in 1907 and commonly considered a gastrointestinal disorder, Whipple's disease primarily causes malabsorption but may affect any part of the body including...

.

Rapidly progressive dementia

Creutzfeldt-Jakob disease
Creutzfeldt-Jakob disease
Creutzfeldt–Jakob disease or CJD is a degenerative neurological disorder that is incurable and invariably fatal. CJD is at times called a human form of mad cow disease, given that bovine spongiform encephalopathy is believed to be the cause of variant Creutzfeldt–Jakob disease in humans.CJD...

 typically causes a dementia which worsens over weeks to months, being caused by prion
Prion
A prion is an infectious agent composed of protein in a misfolded form. This is in contrast to all other known infectious agents which must contain nucleic acids . The word prion, coined in 1982 by Stanley B. Prusiner, is a portmanteau derived from the words protein and infection...

s. The common causes of slowly progressive dementia also sometimes present with rapid progression: Alzheimer's disease
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...

, dementia with Lewy bodies
Dementia with Lewy bodies
Dementia with Lewy bodies , also known under a variety of other names including Lewy body dementia, diffuse Lewy body disease, cortical Lewy body disease, and senile dementia of Lewy type, is a type of dementia closely allied to both Alzheimers and Parkinson's Diseases...

, frontotemporal lobar degeneration
Frontotemporal lobar degeneration
-Further reading:*Hodges, John R. The Frontotemporal Dementia Syndromes. Cambridge University Press. 2007 ISBN 978-0-521-85477-1-External links:****Mayo Clinic - **...

 (including corticobasal degeneration
Corticobasal degeneration
Corticobasal degeneration or Corticobasal Ganglionic Degeneration is a rare progressive neurodegenerative disease involving the cerebral cortex and the basal ganglia. It is characterized by marked disorders in movement and cognitive dysfunction...

 and progressive supranuclear palsy
Progressive supranuclear palsy
Progressive supranuclear palsy is a degenerative disease involving the gradual deterioration and death of specific areas of the brain....

).

On the other hand, encephalopathy
Encephalopathy
Encephalopathy means disorder or disease of the brain. In modern usage, encephalopathy does not refer to a single disease, but rather to a syndrome of global brain dysfunction; this syndrome can be caused by many different illnesses.-Terminology:...

 or delirium
Delirium
Delirium or acute confusional state is a common and severe neuropsychiatric syndrome with core features of acute onset and fluctuating course, attentional deficits and generalized severe disorganization of behavior...

 may develop relatively slowly and resemble dementia. Possible causes include brain infection (viral encephalitis
Viral encephalitis
Viral encephalitis refers to a type of Encephalitis caused by a virus.Encephalitis may be caused by a variety of afflictions.Types include:*Arbovirus encephalitis**La Crosse encephalitis**California encephalitis virus**Japanese Encephalitis**St...

, subacute sclerosing panencephalitis
Subacute sclerosing panencephalitis
Subacute sclerosing panencephalitis is a rare chronic, progressive encephalitis that affects primarily children and young adults, caused by a persistent infection of immune resistant measles virus . No cure for SSPE exists, but the condition can be managed by medication if treatment is started at...

, Whipple's disease
Whipple's disease
Whipple's disease is a rare, systemic infectious disease caused by the bacterium Tropheryma whipplei. First described by George Hoyt Whipple in 1907 and commonly considered a gastrointestinal disorder, Whipple's disease primarily causes malabsorption but may affect any part of the body including...

) or inflammation (limbic encephalitis
Limbic encephalitis
Limbic encephalitis is a form of encephalitis.In a small number of cases, the pathogens responsible for encephalitis attack primarily the limbic system , often causing memory deficits similar to those observed in Alzheimer's disease or Creutzfeldt-Jakob disease Limbic encephalitis is a form of...

, Hashimoto's encephalopathy
Hashimoto's encephalopathy
Hashimoto's Encephalopathy is a very rare condition associated with Hashimoto's thyroiditis. It was first described in 1966. It is classified as a neuroendocrine disorder....

, cerebral vasculitis
Cerebral vasculitis
Cerebral vasculitis or central nervous system vasculitis is vasculitis involving the brain and occasionally the spinal cord...

); tumors such as lymphoma
Primary central nervous system lymphoma
A primary central nervous system lymphoma , also known as microglioma and primary brain lymphoma, is a primary intracranial tumor appearing mostly in patients with severe immunosuppression . PCNSLs represent around 20% of all cases of lymphomas in HIV infections...

 or glioma
Glioma
A glioma is a type of tumor that starts in the brain or spine. It is called a glioma because it arises from glial cells. The most common site of gliomas is the brain.-By type of cell:...

; drug toxicity (e.g. anticonvulsant
Anticonvulsant
The anticonvulsants are a diverse group of pharmaceuticals used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of bipolar disorder, since many seem to act as mood stabilizers, and in the treatment of neuropathic pain. The goal of an...

 drugs); metabolic causes such as liver failure
Hepatic encephalopathy
Hepatic encephalopathy is the occurrence of confusion, altered level of consciousness and coma as a result of liver failure. In the advanced stages it is called hepatic coma or coma hepaticum...

 or kidney failure; and chronic subdural hematoma
Subdural hematoma
A subdural hematoma or subdural haematoma , also known as a subdural haemorrhage , is a type of haematoma, a form of traumatic brain injury. Blood gathers within the outermost meningeal layer, between the dura mater, which adheres to the skull, and the arachnoid mater, which envelops the brain...

.

Dementia as a feature of other conditions

There are many other medical and neurological conditions in which dementia only occurs late in the illness, or as a minor feature. For example, a proportion of patients with Parkinson's disease
Parkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...

 develop dementia, though widely varying figures are quoted for this proportion. When dementia occurs in Parkinson's disease, the underlying cause may be dementia with Lewy bodies
Dementia with Lewy bodies
Dementia with Lewy bodies , also known under a variety of other names including Lewy body dementia, diffuse Lewy body disease, cortical Lewy body disease, and senile dementia of Lewy type, is a type of dementia closely allied to both Alzheimers and Parkinson's Diseases...

 or Alzheimer's disease
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...

, or both. Cognitive impairment also occurs in the Parkinson-plus syndromes of progressive supranuclear palsy
Progressive supranuclear palsy
Progressive supranuclear palsy is a degenerative disease involving the gradual deterioration and death of specific areas of the brain....

 and corticobasal degeneration
Corticobasal degeneration
Corticobasal degeneration or Corticobasal Ganglionic Degeneration is a rare progressive neurodegenerative disease involving the cerebral cortex and the basal ganglia. It is characterized by marked disorders in movement and cognitive dysfunction...

 (and the same underlying pathology may cause the clinical syndromes of frontotemporal lobar degeneration
Frontotemporal lobar degeneration
-Further reading:*Hodges, John R. The Frontotemporal Dementia Syndromes. Cambridge University Press. 2007 ISBN 978-0-521-85477-1-External links:****Mayo Clinic - **...

). Chronic inflammatory conditions of the brain may affect cognition in the long term, including Behçet's disease
Behçet's disease
Behçet's disease is a rare immune-mediated systemic vasculitis that often presents with mucous membrane ulceration and ocular involvements...

, multiple sclerosis
Multiple sclerosis
Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...

, sarcoidosis
Sarcoidosis
Sarcoidosis , also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs. The cause of sarcoidosis is unknown...

, Sjögren's syndrome
Sjögren's syndrome
Sjögren's syndrome , also known as "Mikulicz disease" and "Sicca syndrome", is a systemic autoimmune disease in which immune cells attack and destroy the exocrine glands that produce tears and saliva....

 and systemic lupus erythematosus
Systemic lupus erythematosus
Systemic lupus erythematosus , often abbreviated to SLE or lupus, is a systemic autoimmune disease that can affect any part of the body. As occurs in other autoimmune diseases, the immune system attacks the body's cells and tissue, resulting in inflammation and tissue damage...

. Although the acute porphyria
Porphyria
Porphyrias are a group of inherited or acquired disorders of certain enzymes in the heme bio-synthetic pathway . They are broadly classified as acute porphyrias and cutaneous porphyrias, based on the site of the overproduction and accumulation of the porphyrins...

s may cause episodes of confusion and psychiatric disturbance, dementia is a rare feature of these rare diseases.

Aside from those mentioned above, inherited conditions which may cause dementia alongside other features include:
  • Alexander disease
    Alexander disease
    Alexander disease is a slowly progressing and fatal neurodegenerative disease. It is a very rare disorder which results from a genetic mutation and mostly affects infants and children, causing developmental delay and changes in physical characteristics....

  • Canavan disease
    Canavan disease
    Canavan disease, also called Canavan-Van Bogaert-Bertrand disease, aspartoacylase deficiency or aminoacylase 2 deficiency, is an autosomal recessive degenerative disorder that causes progressive damage to nerve cells in the brain. Canavan disease is also one of the most common degenerative...

  • Cerebrotendinous xanthomatosis
  • DRPLA
  • Fragile X-associated tremor/ataxia syndrome
    Fragile X-associated tremor/ataxia syndrome
    Fragile X-associated tremor/ataxia syndrome is a late onset neurodegenerative disorder associated with problems with movement, memory, and the autonomic nervous system...

  • Glutaric aciduria type 1
  • Krabbe's disease
  • Maple syrup urine disease
    Maple syrup urine disease
    Maple syrup urine disease , also called branched-chain ketoaciduria, is an autosomal recessive metabolic disorder affecting branched-chain amino acids. It is one type of organic acidemia...

  • Niemann Pick disease type C
  • Kufs' disease
    Neuronal Ceroid Lipofuscinosis
    Neuronal Ceroid Lipofuscinoses is the general name for a family of at least eight genetically separate neurodegenerative disorders that result from excessive accumulation of lipopigments in the body's tissues. These lipopigments are made up of fats and proteins...

  • Neuroacanthocytosis
    Neuroacanthocytosis
    Neuroacanthocytosis is a term that refers to a group of genetically diverse conditions complicated by movement disorders, neurological problems and spiculated red blood cells...

  • Organic acidemias
  • Pelizaeus-Merzbacher disease
    Pelizaeus-Merzbacher disease
    Pelizaeus–Merzbacher disease is a rare central nervous system disorder in which coordination, motor abilities, and intellectual function are delayed to variable extents.-Classification:...

  • Urea cycle disorders
  • Sanfilippo syndrome
    Sanfilippo syndrome
    Sanfilippo syndrome, or Mucopolysaccharidosis III is a rare autosomal recessive lysosomal storage disease. It is caused by a deficiency in one of the enzymes needed to break down the glycosaminoglycan heparan sulfate .Although undegraded heparan sulfate is the primary stored substrate,...

     type B
  • Spinocerebellar ataxia
    Spinocerebellar ataxia
    Spinocerebellar ataxia is a progressive, degenerative, genetic disease with multiple types, each of which could be considered a disease in its own right.-Classification:...

     type 2

Diagnosis

Proper differential diagnosis between the types of dementia (cortical
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...

 and subcortical) will require, at the least, referral to a specialist, e.g., a geriatric internist, geriatric psychiatrist, neurologist
Neurologist
A neurologist is a physician who specializes in neurology, and is trained to investigate, or diagnose and treat neurological disorders.Neurology is the medical specialty related to the human nervous system. The nervous system encompasses the brain, spinal cord, and peripheral nerves. A specialist...

, neuropsychologist or geropsychologist. Duration of symptoms must evident for at least six months for a diagnosis of dementia or organic brain syndrome to be made (ICD-10).

Cognitive testing

Sensitivity and specificity of common tests for dementia
Test Sensitivity Specificity Reference
MMSE 71%-92% 56%-96%
3MS 83%-93.5% 85%-90%
AMTS 73%-100% 71%-100%


There exist some brief tests (5–15 minutes) that have reasonable reliability and can be used in the office or other setting to screen cognitive status. Examples of such tests include the abbreviated mental test score
Abbreviated mental test score
The abbreviated mental test score was introduced by Hodkinson in 1972 to rapidly assess elderly patients for the possibility of dementia. Its uses in medicine have become somewhat wider, e.g. to assess for confusion and other cognitive impairment, although it has mainly been validated in the...

 (AMTS), the mini mental state examination (MMSE), Modified Mini-Mental State Examination (3MS), the Cognitive Abilities Screening Instrument (CASI), and the clock drawing test. Scores must be interpreted in the context of the person's educational and other background, and the particular circumstances; for example, a person highly depressed or in great pain will not be expected to do well on many tests of mental ability.

While many tests have been studied, and some may emerge as better alternatives to the MMSE, presently the MMSE is the best studied and most commonly used.

Another approach to screening for dementia is to ask an informant (relative or other supporter) to fill out a questionnaire about the person's everyday cognitive functioning. Informant questionnaires provide complementary information to brief cognitive tests. Probably the best known questionnaire of this sort is the Informant Questionnaire on Cognitive Decline in the Elderly
Informant Questionnaire on Cognitive Decline in the Elderly
The Informant Questionnaire on Cognitive Decline in the Elderly is a questionnaire that can be filled out by a relative or other supporter of an older person to determine whether that person has declined in cognitive functioning. The IQCODE is used as a screening test for dementia...

 (IQCODE)
. On the other hand the General Practitioner Assessment Of Cognition
General Practitioner Assessment Of Cognition
The General Practitioner Assessment of Cognition is a brief screening test for cognitive impairment introduced by Brodaty et al. in 2002. It was specifically developed for the use in the primary care setting.- The test :...

combines both, a patient assessment and an informant interview. It was specifically designed for the use in the primary care setting and is also available as a web-based test.

Further evaluation includes retesting at another date, and administration of other tests of mental function.

Laboratory tests

Routine blood test
Blood test
A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via fingerprick....

s are also usually performed to rule out treatable causes. These tests include vitamin B12
Vitamin B12
Vitamin B12, vitamin B12 or vitamin B-12, also called cobalamin, is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins...

, folic acid
Folic acid
Folic acid and folate , as well as pteroyl-L-glutamic acid, pteroyl-L-glutamate, and pteroylmonoglutamic acid are forms of the water-soluble vitamin B9...

, thyroid-stimulating hormone
Thyroid-stimulating hormone
Thyrotrophin-stimulating hormone is a peptide hormone synthesized and secreted by thyrotrope cells in the anterior pituitary gland, which regulates the endocrine function of the thyroid gland.- Physiology :...

 (TSH), C-reactive protein
C-reactive protein
C-reactive protein is a protein found in the blood, the levels of which rise in response to inflammation...

, full blood count, electrolyte
Electrolyte
In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....

s, calcium
Calcium in biology
Calcium plays a pivotal role in the physiology and biochemistry of organisms and the cell. It plays an important role in signal transduction pathways, where it acts as a second messenger, in neurotransmitter release from neurons, contraction of all muscle cell types, and fertilization...

, renal function
Renal function
Renal function, in nephrology, is an indication of the state of the kidney and its role in renal physiology. Glomerular filtration rate describes the flow rate of filtered fluid through the kidney...

, and liver enzymes. Abnormalities may suggest vitamin deficiency, infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...

 or other problems that commonly cause confusion or disorientation in the elderly. The problem is complicated by the fact that these cause confusion more often in persons who have early dementia, so that "reversal" of such problems may ultimately only be temporary.

Testing for alcohol and other known dementia-inducing drugs may be indicated.

Imaging

A CT scan or magnetic resonance imaging
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...

 (MRI scan) is commonly performed, although these modalities do not have optimal sensitivity for the diffuse metabolic changes associated with dementia in a patient that shows no gross neurological problems (such as paralysis or weakness) on neurological exam. CT or MRI may suggest normal pressure hydrocephalus
Normal pressure hydrocephalus
Normal pressure hydrocephalus , also termed symptomatic hydrocephalus, occurs when there is an increase in intracranial pressure due to an abnormal accumulation of cerebrospinal fluid in the ventricles of the brain, which can cause ventriculomegaly...

, a potentially reversible cause of dementia, and can yield information relevant to other types of dementia, such as infarction (stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...

) that would point at a vascular type of dementia.

The functional neuroimaging
Functional neuroimaging
Functional neuroimaging is the use of neuroimaging technology to measure an aspect of brain function, often with a view to understanding the relationship between activity in certain brain areas and specific mental functions...

 modalities of SPECT and PET
Positron emission tomography
Positron emission tomography is nuclear medicine imaging technique that produces a three-dimensional image or picture of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide , which is introduced into the body on a...

 are more useful in assessing long-standing cognitive dysfunction, since they have shown similar ability to diagnose dementia as a clinical exam. The ability of SPECT to differentiate the vascular cause from the Alzheimer's disease cause of dementias, appears to be superior to differentiation by clinical exam.

Recent research has established the value of PET imaging using carbon-11 Pittsburgh Compound B as a radiotracer (PIB-PET) in predictive diagnosis of various kinds of dementia, in particular Alzheimer's disease
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...

. Studies from Australia have found PIB-PET to be 86% accurate in predicting which patients with mild cognitive impairment would develop Alzheimer's disease within two years. In another study, carried out using 66 patients seen at the University of Michigan, PET studies using either PIB or another radiotracer, carbon-11 dihydrotetrabenazine (DTBZ), led to more accurate diagnosis for more than one-fourth of patients with mild cognitive impairment or mild dementia.

Prevention

A study done at the University of Bari in Italy, found that a group drinking alcoholic beverages moderately had a slower progression to dementia. In a group of 1,566 elderly Italians, 1,445 had no cognitive impairment and 121 had suffered mild cognitive impairment
Mild cognitive impairment
Mild cognitive impairment is a brain-function syndrome involving the onset and evolution of cognitive impairments beyond those expected based on the age and education of the individual, but which are not significant enough to interfere with their daily activities...

, the study found that that over the duration of 3.5 years the people with MCI
MCI
MCI may refer to:* 1101 in Roman numerals*mCi, millicurie, 1/1000 of a curie, a non-SI unit of radioactivity*MCi, megacurie, 1,000,000 times a curie-Company:...

 who drank less than one alcoholic beverage a day progressed to dementia at a rate that was 85% slower then those who drank no alcoholic beverages. However, the authors of the study commented that since it was epidemiologic, the findings might only be a marker of lifestyle, showing that "moderate lifestyle" in general is associated with slower dementia-progression.A study failed to show a conclusive link between high blood pressure and developing dementia. The study, published in the Lancet Neurology journal July 2008, found that blood pressure lowering medication did not reduce dementia but that meta analysis of the study data combined with other data suggested that further study could be warranted.

Brain-derived neurotrophic factor
Brain-derived neurotrophic factor
Brain-derived neurotrophic factor, also known as BDNF, is a protein that, in humans, is encoded by the BDNF gene. BDNF is a member of the "neurotrophin" family of growth factors, which are related to the canonical "Nerve Growth Factor", NGF...

 (BDNF) expression is associated with some dementia types.

A Canadian study found that a lifetime of bilingualism delays the onset of dementia by an average of four years when compared to monolingual patients.

Management

Except for the treatable types listed above, there is no cure to this illness. Cholinesterase inhibitor
Acetylcholinesterase inhibitor
An acetylcholinesterase inhibitor or anti-cholinesterase is a chemical that inhibits the cholinesterase enzyme from breaking down acetylcholine, increasing both the level and duration of action of the neurotransmitter acetylcholine.- Uses :Acetylcholinesterase inhibitors:* Occur naturally as...

s are often used early in the disease course. Cognitive and behavioral interventions may also be appropriate. Educating and providing emotional support to the caregiver
Caregiver
Caregiver may refer to:* Caregiver or carer - an unpaid person who cares for someone requiring support due to a disability, frailty, mental health problem, learning disability or old age...

 (or carer) is of importance as well (see also elderly care
Elderly care
Elderly care or simply eldercare is the fulfillment of the special needs and requirements that are unique to senior citizens. This broad term encompasses such services as assisted living, adult day care, long term care, nursing homes, hospice care, and In-Home care.-Cultural and geographic...

).

Pain and dementia

As people age, they experience more health problems, and most health problems associated with aging carry a substantial burden of pain; so, between 25% and 50% of older adults experience persistent pain. Seniors with dementia experience the same prevalence of conditions likely to cause pain as seniors without dementia. Pain is often overlooked in older adults and, when screened for, often poorly assessed, especially among those with dementia since they become incapable of informing others that they're in pain. Beyond the issue of humane care, unrelieved pain has functional implications. Persistent pain can lead to decreased ambulation, depressed mood, sleep disturbances, impaired appetite and exacerbation of cognitive impairment, and pain-related interference with activity is a factor contributing to falls in the elderly.

Although persistent pain in the person with dementia is difficult to communicate, diagnose and treat, failure to address persistent pain has profound functional, psychosocial
Psychosocial
For a concept to be psychosocial means it relates to one's psychological development in, and interaction with, a social environment. The individual needs not be fully aware of this relationship with his or her environment. It was first commonly used by psychologist Erik Erikson in his stages of...

 and quality of life
Quality of life
The term quality of life is used to evaluate the general well-being of individuals and societies. The term is used in a wide range of contexts, including the fields of international development, healthcare, and politics. Quality of life should not be confused with the concept of standard of...

 implications for this vulnerable population. Health professionals often lack the skills and usually lack the time needed to recognize, accurately assess and adequately monitor pain in people with dementia. Family members and friends can make a valuable contribution to the care of a person with dementia by learning to recognize and assess their pain. Educational resources (such as the tutorial) and observational assessment tools are available.

Medications

Currently, there are no medications that are clinically proven to be preventative or curative of dementia.
Although some medications are approved for use in the treatment of dementia, these treat the behavioural and cognitive symptoms of dementia, but have no effect on the underlying pathophysiology.
  • Acetylcholinesterase inhibitor
    Acetylcholinesterase inhibitor
    An acetylcholinesterase inhibitor or anti-cholinesterase is a chemical that inhibits the cholinesterase enzyme from breaking down acetylcholine, increasing both the level and duration of action of the neurotransmitter acetylcholine.- Uses :Acetylcholinesterase inhibitors:* Occur naturally as...

    s: Tacrine
    Tacrine
    Tacrine is a centrally acting anticholinesterase and indirect cholinergic agonist . It was the first centrally-acting cholinesterase inhibitor approved for the treatment of Alzheimer's disease, and was marketed under the trade name Cognex. Tacrine was first synthesised by Adrien Albert at the...

     (Cognex), donepezil
    Donepezil
    Donepezil, marketed under the trade name Aricept by its developer Eisai and partner Pfizer, is a centrally acting reversible acetylcholinesterase inhibitor. Its main therapeutic use is in the palliative treatment of mild to moderate Alzheimer's disease. Common side effects include...

     (Aricept), galantamine
    Galantamine
    Galantamine is used for the treatment of mild to moderate Alzheimer’s disease and various other memory impairments, in particular those of vascular origin...

     (Razadyne), and rivastigmine
    Rivastigmine
    Rivastigmine is a parasympathomimetic or cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer’s type and dementia due to Parkinson's disease. The drug can be administered orally or via a transdermal patch; the latter form reduces the prevalence of side effects, which...

     (Exelon) are approved by the United States Food and Drug Administration (FDA) for treatment of dementia induced by Alzheimer's disease. They may be useful for other similar diseases causing dementia such as Parkinsons or vascular dementia. Acetylcholinesterase inhibitor
    Acetylcholinesterase inhibitor
    An acetylcholinesterase inhibitor or anti-cholinesterase is a chemical that inhibits the cholinesterase enzyme from breaking down acetylcholine, increasing both the level and duration of action of the neurotransmitter acetylcholine.- Uses :Acetylcholinesterase inhibitors:* Occur naturally as...

    s aim to increase the amount of the neurotransmitter
    Neurotransmitter
    Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...

     acetylcholine
    Acetylcholine
    The chemical compound acetylcholine is a neurotransmitter in both the peripheral nervous system and central nervous system in many organisms including humans...

    , which is deficient in people with dementia. This is done by inhibiting the action of the enzyme acetylcholinesterase
    Acetylcholinesterase
    "Acetylcholinesterase, also known as AChE or acetylcholine acetylhydrolase, is an enzyme that degrades the neurotransmitter acetylcholine, producing choline and an acetate group. It is mainly found at neuromuscular junctions and cholinergic nervous system, where its activity serves to terminate...

    , which breaksdown acetylcholine as part of normal brain function. Though these medications are commonly prescribed, in a minority of patients these drugs can cause side effects including bradycardia
    Bradycardia
    Bradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart...

     and syncope
    Syncope (medicine)
    Syncope , the medical term for fainting, is precisely defined as a transient loss of consciousness and postural tone characterized by rapid onset, short duration, and spontaneous recovery due to global cerebral hypoperfusion that most often results from hypotension.Many forms of syncope are...

    .
  • N-methyl-D-aspartate (NMDA) receptor
    NMDA receptor
    The NMDA receptor , a glutamate receptor, is the predominant molecular device for controlling synaptic plasticity and memory function....

     blockers: Memantine is marketed under several names by different pharmaceutical companies including: Abixa, Akatinol, Axura, Ebixa, Memox and Namenda. In dementia, NMDA receptors are over-stimulated by glutamate, which creates problems for neurotransmission
    Neurotransmission
    Neurotransmission , also called synaptic transmission, is the process by which signaling molecules called neurotransmitters are released by a neuron , and bind to and activate the receptors of another neuron...

     (and thus cognition
    Cognition
    In science, cognition refers to mental processes. These processes include attention, remembering, producing and understanding language, solving problems, and making decisions. Cognition is studied in various disciplines such as psychology, philosophy, linguistics, and computer science...

    ) and also leads to damage to neurons through excitotoxicity
    Excitotoxicity
    Excitotoxicity is the pathological process by which nerve cells are damaged and killed by excessive stimulation by neurotransmitters such as glutamate and similar substances. This occurs when receptors for the excitatory neurotransmitter glutamate such as the NMDA receptor and AMPA receptor are...

    . Memantine is thought to work by improving the “signal-to-noise” ratio and preventing excitotoxic damage. Hence, due to their differing mechanisms of action memantine and acetylcholinesterase inhibitors can be used in combination with each other.

Off label

  • Antidepressant
    Antidepressant
    An antidepressant is a psychiatric medication used to alleviate mood disorders, such as major depression and dysthymia and anxiety disorders such as social anxiety disorder. According to Gelder, Mayou &*Geddes people with a depressive illness will experience a therapeutic effect to their mood;...

     drugs: Depression
    Clinical depression
    Major depressive disorder is a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities...

     is frequently associated with dementia and generally worsens the degree of cognitive and behavioral impairment. Antidepressant
    Antidepressant
    An antidepressant is a psychiatric medication used to alleviate mood disorders, such as major depression and dysthymia and anxiety disorders such as social anxiety disorder. According to Gelder, Mayou &*Geddes people with a depressive illness will experience a therapeutic effect to their mood;...

    s effectively treat the cognitive and behavioral symptoms of depression in patients with Alzheimer's disease, but evidence for their use in other forms of dementia is weak.
  • Anxiolytic
    Anxiolytic
    An anxiolytic is a drug used for the treatment of anxiety, and its related psychological and physical symptoms...

     drugs: Many patients with dementia experience anxiety
    Anxiety
    Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...

     symptoms. Although benzodiazepines like diazepam
    Diazepam
    Diazepam , first marketed as Valium by Hoffmann-La Roche is a benzodiazepine drug. Diazepam is also marketed in Australia as Antenex. It is commonly used for treating anxiety, insomnia, seizures including status epilepticus, muscle spasms , restless legs syndrome, alcohol withdrawal,...

     (Valium) have been used for treating anxiety in other situations, they are often avoided because they may increase agitation in persons with dementia and are likely to worsen cognitive problems or are too sedating. Buspirone
    Buspirone
    Buspirone is an anxiolytic psychoactive drug of the azapirone chemical class, and is primarily used to treat generalized anxiety disorder Bristol-Myers Squibb gained FDA approval of buspirone in 1986 for treatment of GAD...

     (Buspar) is often initially tried for mild-to-moderate anxiety. There is little evidence for the effectiveness of benzodiazepines in dementia, whereas there is evidence for the effectivess of antipsychotics (at low doses).
  • Selegiline
    Selegiline
    Selegiline is a drug used for the treatment of early-stage Parkinson's disease, depression and senile dementia. In normal clinical doses it is a selective irreversible MAO-B inhibitor, however in larger doses it loses its specificity and also inhibits MAO-A...

    , a drug used primarily in the treatment of Parkinson's disease, appears to slow the development of dementia. Selegiline is thought to act as an antioxidant
    Antioxidant
    An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

    , preventing free radical damage. However, it also acts as a stimulant, making it difficult to determine whether the delay in onset of dementia symptoms is due to protection from free radicals or to the general elevation of brain activity from the stimulant effect.
  • Antipsychotic drugs: Both typical antipsychotics (such as Haloperidol
    Haloperidol
    Haloperidol is a typical antipsychotic. It is in the butyrophenone class of antipsychotic medications and has pharmacological effects similar to the phenothiazines....

    ) and atypical antipsychotics such as (risperidone
    Risperidone
    Risperidone is a second generation or atypical antipsychotic, sold under the trade name . It is used to treat schizophrenia , schizoaffective disorder, the mixed and manic states associated with bipolar disorder, and irritability in people with autism...

    ) increase the risk of death in dementia-associated psychosis. This means that any use of antipsychotic medication for dementia-associated psychosis is off-label and should only be considered after discussing the risks and benefits of treatment with these drugs, and after other treatment modalities have failed. In the UK around 144,000 dementia sufferers are unnecessarily prescribed antipsychotic drugs, around 2000 patients die as a result of taking the drugs each year.

Services

Adult daycare centers as well as special care units in nursing homes often provide specialized care for dementia patients. Adult daycare centers offer supervision, recreation, meals, and limited health care to participants, as well as providing respite for caregivers.

In addition, Home care
Home care
Home Care, , is health care or supportive care provided in the patient's home by healthcare professionals Home Care, (also referred to as domiciliary care or social care), is health care or supportive care provided in the patient's home by healthcare professionals Home Care, (also referred to as...

 can provide one-on-one support and care in the home allowing for more individualized attention that is needed as the disease progresses.

While some preliminary studies have found that music therapy
Music therapy
Music therapy is an allied health profession and one of the expressive therapies, consisting of an interpersonal process in which a trained music therapist uses music and all of its facets—physical, emotional, mental, social, aesthetic, and spiritual—to help clients to improve or maintain their...

 may be useful in helping patients with dementia, their quality has been low and no reliable conclusions can be drawn from them.

Nursing people with dementia

Psychiatric nurses can make a distinctive contribution to people's mental health. The four main premises upon which psychiatric nursing is based are:
  • The nursing is an interactive, developmental human activity that is more concerned with the future development of the person than the origins.
  • The experience of mental distress related to the psychiatric disorder is represented through disturbances or reports of private events that are known only to the person concerned.
  • Nurses and the people in care are engaged in a relationship based on mutual influence.
  • The experience of psychiatric disorder is translated into problems of everyday living and the nurse notes the human responses to the psychiatric distress, not the disorder.

Feeding tubes

There is little evidence, even after widespread use, that feeding tubes help patients with advanced dementia gain weight, regain strength or function, prevent aspiration pneumonias, or improve quality of life. The risks associated with the use of tubes are not well known.

Epidemiology

Evidence from well-planned, representative epidemiological surveys is scarce in many regions, particularly in low-income countries. However, estimates from 2005 suggest a global dementia prevalence of 24.3 million, with 4.6 million new cases of dementia every year. The number of people affected will double every 20 years to 81.1 million by 2040.

See also

  • Aging brain
    Aging brain
    Age is a major risk factor for most common neurodegenerative diseases, including Alzheimer's disease, cerebrovascular disease, Parkinson's disease and Lou Gehrig's disease. Other risk factors, including genetic mutations, low educational attainments and head injury contribute much less to the risk...

  • Caregiving and dementia
    Caregiving and dementia
    As populations age, caregiving and dementia become more common aspects of life. In most mild to medium cases of dementia the primary caregiver is a family member, usually a spouse or adult child...

  • Montessori-Based Dementia Programming
    Montessori-Based Dementia Programming
    Montessori-Based Dementia Programming is a method of working witholder adults living with cognitive and/or physical impairments based on the ideas of the educator Maria Montessori. It has been shown to increase levels of engagement and participation in activities of persons with dementia...

  • Agitation (dementia)
    Agitation (dementia)
    Agitation often accompanies dementia and often precedes the diagnosis of common age-related disorders of cognition such as Alzheimer's disease...

  • Cognitive orthotics
    Cognitive orthotics
    Cognitive orthotics are software-based personal reminder systems for people with cognitive impairment, such as memory loss. People who can benefit include the elderly, people who have experienced traumatic brain injury, and anyone who experiences memory loss. These devices may be installed on...

  • Sundowning (dementia)
    Sundowning (dementia)
    In medicine, sundowning, also known as sundown syndrome, is a syndrome involving the occurrence or increase of one or more abnormal behaviors in a circadian rhythm. Sundowning typically occurs during the late afternoon, evening, and night, hence the name. It occurs in persons with certain forms of...

  • Wandering (dementia)
    Wandering (dementia)
    Wandering, in persons with dementia, is a common behavior that can cause great risk for the person, and is often the major priority for caregivers. It is estimated to be the most common form disruption from people with dementia within institutions. Although it occurs in several types of...

  • Aging movement control
    Aging movement control
    Normal aging movement control in human is about the changes on the muscles, motor neurons, nerves, sensory functions, gait, fatigue, visual and manual responses, in men and women as they get older but who do not have neurological, muscular or neuromuscular disorder...


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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