Klüver-Bucy syndrome
Encyclopedia
Klüver-Bucy syndrome is a behavioral disorder that occurs when both the right and left medial temporal lobe
s of the brain
malfunction. The amygdala
has been a particularly implicated brain region in the pathogenesis of this syndrome. The syndrome is named for Heinrich Klüver
and Paul Bucy
.
While this cluster of syndromes is common to such sources as 1997's The Neuropsychiatry of Limbic and Subcortical Disorders, 2005's Functional Neuroanatomy: Text and Atlas and 1997's "Single-Photon Emission CT and MR Findings in Klüver-Bucy after Reye syndrome", an article in the American Journal of Neuroradiology, the three vary thereafter.
Inconsistent criteria include:
, Klüver arranged to have the temporal lobes of a number of rhesus monkeys bilaterally removed by Bucy, a neurosurgeon. Klüver did not find the expected impact on response to mescaline, but did observe a series of changes in the subject animals. The six points of difference that Klüver recorded were visual agnosia, an increased tendency to explore items by mouth, hypermetamorphosis
, dampening of emotional expression, altered sexual behavior and differences in diet. Klüver later discovered similar observations by Sanger Brown
and Edward Albert Sharpey-Schafer that had been published in 1881 and drew on these to substantiate his own observations.
Monkeys in the Klüver-Bucy experiment evidently had normal vision and motor skills, but exhibited "psychic blindness", what Rusiko Bourtchouladze described in 2004 as an inability to recognize "the emotional importance of events". They did not display fear for items that would ordinarily frighten members of their species; they displayed an appetite for improper foods such as rocks or live rats and sought intercourse with unusual partners, including members of other species. They became extremely interested in exploring items in their environment and became placid when approached.
in 1975 by Marlowe et al. Klüver-Bucy syndrome can manifest after either of these (lobectomies can be medically required by such reasons as accidents or tumor
s), but may also appear in humans with acute herpes simplex encephalitis or following a stroke
. Other conditions may also contribute to a diagnosis of Klüver-Bucy syndrome, including Alzheimer's Disease
, ischemia
, anoxia
, progressive subcortical gliosis
, Rett syndrome
, porphyria
and carbon monoxide poisoning
, among others.
It is rare for humans to manifest all of the identified symptoms of the syndrome; three or more are required for diagnosis. Among humans, the most common symptoms include placidity, hyperorality and dietary changes. They may also present with an inability to recognize objects or inability to recognize faces
or other memory disorder
s.
Temporal lobe
The temporal lobe is a region of the cerebral cortex that is located beneath the Sylvian fissure on both cerebral hemispheres of the mammalian brain....
s of the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
malfunction. The amygdala
Amygdala
The ' are almond-shaped groups of nuclei located deep within the medial temporal lobes of the brain in complex vertebrates, including humans. Shown in research to perform a primary role in the processing and memory of emotional reactions, the amygdalae are considered part of the limbic system.-...
has been a particularly implicated brain region in the pathogenesis of this syndrome. The syndrome is named for Heinrich Klüver
Heinrich Klüver
Heinrich Klüver was a German-American psychologist born in Holstein, Germany.After having served in the Imperial Germany Army during World War I, he studied at both the University of Hamburg and the University of Berlin from 1920-23. In the latter year, he arrived in the United States to attend...
and Paul Bucy
Paul Bucy
Paul Bucy was an American neuropathologist who was a native of Hubbard, Iowa. He studied medicine at the University of Iowa, and afterwards was an assistant to neurosurgeon Percival Bailey at the University of Chicago...
.
Symptoms
The list of symptoms differs somewhat by source. Generally included are the following:- Docility. Characterized by exhibiting diminished fear responses or reacting with unusually low aggression. This has also been termed "placidity" or "tameness".
- Dietary changes and/or Hyperphagia. Characterized by eating inappropriate objects (picaPica (disorder)Pica is characterized by an appetite for substances largely non-nutritive . For these actions to be considered pica, they must persist for more than one month at an age where eating such objects is considered developmentally inappropriate...
) and/or overeating. - Hyperorality. This was described by Ozawa et al. as "an oral tendency, or compulsion to examine objects by mouth".
- HypersexualityHypersexualityHypersexuality is extremely frequent or suddenly increased sexual urges or sexual activity. Hypersexuality is typically associated with lowered sexual inhibitions. Although hypersexuality can be caused by some medical conditions or medications, in most cases the cause is unknown...
. Characterized by a heightened sex drive or a tendency to seek sexual stimulation from unusual or inappropriate objects. - Visual agnosiaVisual agnosiaVisual agnosia is the inability of the brain to make sense of or make use of some part of otherwise normal visual stimulus and is typified by the inability to recognize familiar objects or faces...
. Characterized by an inability to recognize familiar objects or people.
While this cluster of syndromes is common to such sources as 1997's The Neuropsychiatry of Limbic and Subcortical Disorders, 2005's Functional Neuroanatomy: Text and Atlas and 1997's "Single-Photon Emission CT and MR Findings in Klüver-Bucy after Reye syndrome", an article in the American Journal of Neuroradiology, the three vary thereafter.
Inconsistent criteria include:
- HypermetamorphosisHypermetamorphosisHypermetamorphosis is a kind of complete insect metamorphosis in which the different larval instars represent two or more different forms of larva. As the larva molts its morphology can change from that of a campodeiform to scarabaeiform or to vermiform...
, characterized by Ozawa et al. as "an irresistible impulse to notice and react to everything within sight". This is included under the classification systems described by The Neuropsychiatry of Limbic and Subcortical Disorders and "Single-Photon Emission CT and MR Findings in Klüver-Bucy". - Lack of emotional response, diminished emotional affectAffect (psychology)Affect refers to the experience of feeling or emotion. Affect is a key part of the process of an organism's interaction with stimuli. The word also refers sometimes to affect display, which is "a facial, vocal, or gestural behavior that serves as an indicator of affect" .The affective domain...
. This is a symptom under The Neuropsychiatry of Limbic and Subcortical Disorders and is included under "Single-Photon Emission CT and MR Findings in Klüver-Bucy" along with apathyApathyApathy is a state of indifference, or the suppression of emotions such as concern, excitement, motivation and passion. An apathetic individual has an absence of interest in or concern about emotional, social, spiritual, philosophical or physical life.They may lack a sense of purpose or meaning in...
under docility. - Memory loss. This symptom is listed in The Neuropsychiatry of Limbic and Subcortical Disorders. It is also referenced by the National Institute of Neurological Disorders and StrokeNational Institute of Neurological Disorders and StrokeThe National Institute of Neurological Disorders and Stroke is a part of the U.S. National Institutes of Health . It conducts and funds research on brain and nervous system disorders and has a budget of just over US$1.5 billion...
.
In rhesus monkeys
As part of an investigation by Klüver in the 1930s into the area affected by mescalineMescaline
Mescaline or 3,4,5-trimethoxyphenethylamine is a naturally occurring psychedelic alkaloid of the phenethylamine class used mainly as an entheogen....
, Klüver arranged to have the temporal lobes of a number of rhesus monkeys bilaterally removed by Bucy, a neurosurgeon. Klüver did not find the expected impact on response to mescaline, but did observe a series of changes in the subject animals. The six points of difference that Klüver recorded were visual agnosia, an increased tendency to explore items by mouth, hypermetamorphosis
Hypermetamorphosis
Hypermetamorphosis is a kind of complete insect metamorphosis in which the different larval instars represent two or more different forms of larva. As the larva molts its morphology can change from that of a campodeiform to scarabaeiform or to vermiform...
, dampening of emotional expression, altered sexual behavior and differences in diet. Klüver later discovered similar observations by Sanger Brown
Sanger Brown
Sanger Brown was an American physician. He was born in Bloomfield , Canada, graduated in 1880 at the Bellevue Hospital Medical College , was assistant physician at the Bloomingdale Asylum for the Insane in 1882–1885, and acting medical superintendent there in 1886...
and Edward Albert Sharpey-Schafer that had been published in 1881 and drew on these to substantiate his own observations.
Monkeys in the Klüver-Bucy experiment evidently had normal vision and motor skills, but exhibited "psychic blindness", what Rusiko Bourtchouladze described in 2004 as an inability to recognize "the emotional importance of events". They did not display fear for items that would ordinarily frighten members of their species; they displayed an appetite for improper foods such as rocks or live rats and sought intercourse with unusual partners, including members of other species. They became extremely interested in exploring items in their environment and became placid when approached.
In humans
Klüver-Bucy syndrome was first documented among humans who had experienced temporal lobectomy in 1955 by H. Terzian and G.D. Ore. It was first noted in a human with meningoencephalitisMeningoencephalitis
Meningoencephalitis is a medical condition that simultaneously resembles both meningitis, which is an infection or inflammation of the meninges, and encephalitis, which is an infection or inflammation of the brain.-Causes:...
in 1975 by Marlowe et al. Klüver-Bucy syndrome can manifest after either of these (lobectomies can be medically required by such reasons as accidents or tumor
Tumor
A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...
s), but may also appear in humans with acute herpes simplex encephalitis or following a 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...
. Other conditions may also contribute to a diagnosis of Klüver-Bucy syndrome, including 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...
, ischemia
Ischemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...
, anoxia
Hypoxia (medical)
Hypoxia, or hypoxiation, is a pathological condition in which the body as a whole or a region of the body is deprived of adequate oxygen supply. Variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise...
, progressive subcortical gliosis
Gliosis
Gliosis is a proliferation of astrocytes in damaged areas of the central nervous system . This proliferation usually leads to the formation of a glial scar....
, Rett syndrome
Rett syndrome
Rett syndrome is a neurodevelopmental disorder of the grey matter of the brain that almost exclusively affects females. The clinical features include small hands and feet and a deceleration of the rate of head growth . Repetitive hand movements, such as wringing and/or repeatedly putting hands into...
, 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...
and carbon monoxide poisoning
Carbon monoxide poisoning
Carbon monoxide poisoning occurs after enough inhalation of carbon monoxide . Carbon monoxide is a toxic gas, but, being colorless, odorless, tasteless, and initially non-irritating, it is very difficult for people to detect...
, among others.
It is rare for humans to manifest all of the identified symptoms of the syndrome; three or more are required for diagnosis. Among humans, the most common symptoms include placidity, hyperorality and dietary changes. They may also present with an inability to recognize objects or inability to recognize faces
Prosopagnosia
Prosopagnosia is a disorder of face perception where the ability to recognize faces is impaired, while the ability to recognize other objects may be relatively intact...
or other memory disorder
Memory disorder
Memory can be defined as an organism's ability to encode, retain, and recall information. Disorders of memory can range from mild to severe, yet are all a result of damage to neuroanatomical structures; either in part or in full. This damage hinders the storage, retention and recollection of memories...
s.