Vertebrobasilar insufficiency
Encyclopedia
Vertebrobasilar insufficiency (VBI), or vertebral basilar ischemia
(also called Beauty parlour syndrome (BPS)), refers to a temporary set of symptoms due to decreased blood flow in the posterior circulation of the brain. The posterior circulation supplies blood to the medulla
, cerebellum
, pons
, midbrain, thalamus
, and occipital cortex (responsible for vision). Therefore, the symptoms due to VBI vary according to which portions of the brain experience significantly decreased blood flow (see image of brain http://www.ama-assn.org/ama1/pub/upload/images/446/brainside.gif). In the United States, 25% of stroke
s and transient ischemic attack
s occur in the vertebrobasilar distribution. These must be separated from strokes arising from the anterior circulation, which involves the carotid arteries.
, which is the most common cause of VBI, it affects men twice as often as women and patients with hypertension
, diabetes, smoking, and dyslipidemias have a higher risk of developing VBI.
VBI, often provoked by sudden and temporary drops in blood pressure, can cause transient ischemic attacks. Postural changes (see orthostatic hypotension
), such as getting out of bed too quickly or standing up after sitting for extended periods of time, often provoke these attacks. Exercise of the legs, or the sudden ceasation of leg exercises, may also bring on the symptoms of VBI. For the sedentary older subject, going up a flight of stairs or walking the dog may be enough to cause pooling of blood in the legs and a drop in blood pressure in the distal arteries of the head. Heat and dehydration
may also be contributing causes.
Mechanical forces acting upon the neck at any age can cause VBI by exacerbating arterial insufficiency or outright occluding one or both vertebrobasilar arteries. Internal forces include those caused by turning the head to an extreme angle to the side, especially with the neck extended. The patient can create this condition while practicing yoga, driving a vehicle in reverse, shooting a bow and arrow, bird watching, or stargazing. External forces include those caused by sports or other physical contact.
identified five patients who suffered strokes as a result of prolonged distortion of their necks from sitting at salon wash basins.
In 1997 medical journal The Lancet published a report by two British doctors about a 42-year-old woman who suffered a stroke after having her hair washed.
The experts said the stroke was due to
The doctors recommended that hairdressers use a cushion and that the neck is not overextended. As a result of this recommendation there have been several sink cushions developed including Nekeze, Hairtools Basin Neck Cushion and the Soft n Style cushion. Trainee Hairdressers are also being taught to make sure that their clients are comfortable.
Several recent studies of the causes of strokes have identified how salon washing basins exert stress on the neck, causing the carotid or vertebral arteries to tear.
David Bateman, a consultant neurologist at Cumberland Infirmary, said that
Dr Bateman went onto say
Other such triggers, which normally require ten minutes of neck overextension, include fairground rides, dentists’ chairs, sit-up exercises and yoga. Another cause, known as Golden Gate Bridge Syndrome, is prompted by excessive strain of looking up.
.
Vertigo
(commonly described as the environment spinning or as if the person is twirling in space) is the most recognizable and quite often the sole symptom of decreased blood flow in the vertebrobasilar distribution. The vertigo due to VBI rarely is brought on by head turning, which could occlude the ipsilateral vertebral artery and result in decreased blood flow to the brain if the contralateral artery is occluded. When the vertigo is accompanied by double vision (diplopia
), graying of vision, and blurred vision, patients often go to the ophthalmologist. If the VBI progresses, there may be weakness of the quadriceps and, to the patient, this is felt as a buckling of the knees. The patient may suddenly become weak at the knee and crumple (often referred to as a “drop attack”). Such a fall can lead to significant head and orthopedic injury, especially in the elderly.
Transient ischemic attacks due to VBI will, by definition, have symptoms resolved within 24 hours. More often, however, the symptoms are very brief, lasting a few seconds to half an hour. Though uncommon and thought to affect only people with already weakened neck arteries, the syndrome has been at the centre of a debate in several recent stroke deaths.
, vestibular neuronitis
, and benign paroxysmal positional vertigo
) that have overlapping signs and symptoms. However, the exact work-up largely depends on the patient’s age and known risk factors. For middle-aged patients, a cardiovascular risk factor evaluation is important. This often includes a cholesterol level, lipid profile (see this http://www.americanheart.org/presenter.jhtml?identifier=183 to determine what your cholesterol level means), ECG, and echocardiogram. If a person with VBI is under age 45 and has no evidence for atherosclerosis, a work-up for hypercoagulable states (Lupus anticoagulant, anti-cardiolipin antibodies
, protein C, protein S, antithrombin III deficiencies) is indicated.
Imaging studies are rarely required to diagnose VBI, but sometimes computed tomography (CT) is performed first. The CT is extremely sensitive in detecting hemorrhage. However, magnetic resonance imaging (MRI) is superior to the CT in detecting ischemic changes in the vertebrobasilar distribution. Magnetic resonance angiography (MRA) also can be used to identify vertebrobasilar stenoses or occlusions, but it can often overestimate the degree of stenosis, or wrongly show stenosis as an occlusion. Intracranial MRA is mostly sufficient to evaluate vertebrobasilar arteries, while extracranial vertebral arteries are better diagnosed using contrast-enhanced MRA, which is less dependent on flow phenomena and more accurate in evaluating stenosis.
CT angiography is also highly accurate in evaluation vertebrobasilar vessels, but ionizing radiation and use of nephrotoxic contrast media make it less suitable both in elderly with renal insufficiency and young adults because of radiation exposure. Moreover, vessel wall calcification and beam-hardening artifacts due to dense bones or metal fillings sometimes cause strong CT-image degradation.
In the event that a patient suffers a “drop attack,” and especially for the elderly population, the most important action is to be evaluated for associated head or other injuries. To prevent drop attacks, patients are advised to “go to the ground” before the knees buckle and shortly after feeling dizzy or experiencing changes in vision. Patients should not be concerned about the social consequences of suddenly sitting on the floor, whether in the mall or sidewalk, as such actions are important in preventing serious injuries.
Sometimes, to prevent further occlusion of blood vessels, patients are started on an antiplatelet agent (aspirin, clopidogrel, or aspirin/dipyridamole) or sometimes an anticoagulant (warfarin) once hemorrhage has been excluded with imaging.
For treatment of vertebrobasilar stenosis due to atherosclerosis, researchers from Stanford University found that intracranial angioplasty can be performed with an annual stroke rate in the territory of treatment of 3.2% and 4.4% for all strokes, including periprocedural events. Randomized control trials need to be performed.
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...
(also called Beauty parlour syndrome (BPS)), refers to a temporary set of symptoms due to decreased blood flow in the posterior circulation of the brain. The posterior circulation supplies blood to the medulla
Medulla oblongata
The medulla oblongata is the lower half of the brainstem. In discussions of neurology and similar contexts where no ambiguity will result, it is often referred to as simply the medulla...
, cerebellum
Cerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
, pons
Pons
The pons is a structure located on the brain stem, named after the Latin word for "bridge" or the 16th-century Italian anatomist and surgeon Costanzo Varolio . It is superior to the medulla oblongata, inferior to the midbrain, and ventral to the cerebellum. In humans and other bipeds this means it...
, midbrain, thalamus
Thalamus
The thalamus is a midline paired symmetrical structure within the brains of vertebrates, including humans. It is situated between the cerebral cortex and midbrain, both in terms of location and neurological connections...
, and occipital cortex (responsible for vision). Therefore, the symptoms due to VBI vary according to which portions of the brain experience significantly decreased blood flow (see image of brain http://www.ama-assn.org/ama1/pub/upload/images/446/brainside.gif). In the United States, 25% of 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 and transient ischemic attack
Transient ischemic attack
A transient ischemic attack is a transient episode of neurologic dysfunction caused by ischemia – either focal brain, spinal cord or retinal – without acute infarction...
s occur in the vertebrobasilar distribution. These must be separated from strokes arising from the anterior circulation, which involves the carotid arteries.
Epidemiology
The incidence of VBI increases with age and typically occurs in the seventh or eighth decade of life. Reflecting atherosclerosisAtherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
, which is the most common cause of VBI, it affects men twice as often as women and patients with hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
, diabetes, smoking, and dyslipidemias have a higher risk of developing VBI.
VBI, often provoked by sudden and temporary drops in blood pressure, can cause transient ischemic attacks. Postural changes (see orthostatic hypotension
Orthostatic hypotension
Orthostatic hypotension, also known as postural hypotension, orthostasis, and colloquially as head rush or dizzy spell, is a form of hypotension in which a person's blood pressure suddenly falls when the person stands up or stretches. The decrease is typically greater than 20/10 mm Hg, and may be...
), such as getting out of bed too quickly or standing up after sitting for extended periods of time, often provoke these attacks. Exercise of the legs, or the sudden ceasation of leg exercises, may also bring on the symptoms of VBI. For the sedentary older subject, going up a flight of stairs or walking the dog may be enough to cause pooling of blood in the legs and a drop in blood pressure in the distal arteries of the head. Heat and dehydration
Dehydration
In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
may also be contributing causes.
Mechanical forces acting upon the neck at any age can cause VBI by exacerbating arterial insufficiency or outright occluding one or both vertebrobasilar arteries. Internal forces include those caused by turning the head to an extreme angle to the side, especially with the neck extended. The patient can create this condition while practicing yoga, driving a vehicle in reverse, shooting a bow and arrow, bird watching, or stargazing. External forces include those caused by sports or other physical contact.
History
VBI was first reported in the early 1990s when an American neurologistNeurologist
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...
identified five patients who suffered strokes as a result of prolonged distortion of their necks from sitting at salon wash basins.
In 1997 medical journal The Lancet published a report by two British doctors about a 42-year-old woman who suffered a stroke after having her hair washed.
The experts said the stroke was due to
"dissection of her right internal carotid artery. Her head had been extended backwards for about five minutes while being washed and after the treatment she felt numb and suffered slurred speech."
The doctors recommended that hairdressers use a cushion and that the neck is not overextended. As a result of this recommendation there have been several sink cushions developed including Nekeze, Hairtools Basin Neck Cushion and the Soft n Style cushion. Trainee Hairdressers are also being taught to make sure that their clients are comfortable.
Several recent studies of the causes of strokes have identified how salon washing basins exert stress on the neck, causing the carotid or vertebral arteries to tear.
David Bateman, a consultant neurologist at Cumberland Infirmary, said that
“salon hairwashing was an identifiable, if small, risk factor for people predisposed to arterial damage. If your neck is stretched and it kinks for a long time, as happens during hairwashing, you stretch the arteries and if you are unlucky you can tear them,” he added “Once you have got that tear in the lining, blood starts flowing between layers of tissue and that can cause blood clots to start building up, leading to a stroke.”
Dr Bateman went onto say
“stroke cases from neck overextension appeared only in people particularly vulnerable to arterial tears, although there was little way of telling who might be at risk. Other factors that contribute to strokes include high blood pressure, diabetes, smoking and raised cholesterol.”
Other such triggers, which normally require ten minutes of neck overextension, include fairground rides, dentists’ chairs, sit-up exercises and yoga. Another cause, known as Golden Gate Bridge Syndrome, is prompted by excessive strain of looking up.
Signs and Symptoms
Vertebrobasilar insufficiency happens when the neck is overextended back into a sink during hairwashing, damaging the blood vessels in the neck and disrupting the blood flow to the brain, resulting in a potential strokeStroke
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...
.
Vertigo
Vertigo (medical)
Vertigo is a type of dizziness, where there is a feeling of motion when one is stationary. The symptoms are due to a dysfunction of the vestibular system in the inner ear...
(commonly described as the environment spinning or as if the person is twirling in space) is the most recognizable and quite often the sole symptom of decreased blood flow in the vertebrobasilar distribution. The vertigo due to VBI rarely is brought on by head turning, which could occlude the ipsilateral vertebral artery and result in decreased blood flow to the brain if the contralateral artery is occluded. When the vertigo is accompanied by double vision (diplopia
Diplopia
Diplopia, commonly known as double vision, is the simultaneous perception of two images of a single object that may be displaced horizontally, vertically, or diagonally in relation to each other...
), graying of vision, and blurred vision, patients often go to the ophthalmologist. If the VBI progresses, there may be weakness of the quadriceps and, to the patient, this is felt as a buckling of the knees. The patient may suddenly become weak at the knee and crumple (often referred to as a “drop attack”). Such a fall can lead to significant head and orthopedic injury, especially in the elderly.
Transient ischemic attacks due to VBI will, by definition, have symptoms resolved within 24 hours. More often, however, the symptoms are very brief, lasting a few seconds to half an hour. Though uncommon and thought to affect only people with already weakened neck arteries, the syndrome has been at the centre of a debate in several recent stroke deaths.
Diagnosis
The evaluation for VBI starts with a history and physical exam, with great emphasis on the cardiovascular and neurologic exam. It also includes a work-up to exclude benign conditions (such as labyrinthitisLabyrinthitis
Labyrinthitis is an inflammation of the inner ear, and a form of unilateral vestibular dysfunction. It derives its name from the labyrinths that house the vestibular system . Labyrinthitis can cause balance disorders....
, vestibular neuronitis
Vestibular neuronitis
Vestibular neuronitis, also called Vestibular neuritis, can be a paroxysmal, single attack of vertigo, a series of attacks, or a persistent condition which diminishes over three to six weeks. It is a type of unilateral vestibular dysfunction and may be associated with nausea, vomiting, and...
, and benign paroxysmal positional vertigo
Benign paroxysmal positional vertigo
Benign paroxysmal positional vertigo is a disorder caused by problems in the inner ear. Its symptoms are repeated episodes of positional vertigo, that is, of a spinning sensation caused by changes in the position of the head.-Classification:...
) that have overlapping signs and symptoms. However, the exact work-up largely depends on the patient’s age and known risk factors. For middle-aged patients, a cardiovascular risk factor evaluation is important. This often includes a cholesterol level, lipid profile (see this http://www.americanheart.org/presenter.jhtml?identifier=183 to determine what your cholesterol level means), ECG, and echocardiogram. If a person with VBI is under age 45 and has no evidence for atherosclerosis, a work-up for hypercoagulable states (Lupus anticoagulant, anti-cardiolipin antibodies
Anti-cardiolipin antibodies
Anti-cardiolipin antibodies are antibodies often directed against cardiolipin and found in several diseases including syphilis, antiphospholipid syndrome, livedoid vasculitis, vertebrobasilar insufficiency, Behçet's syndrome, idiopathic spontaneous abortion, and systemic lupus erythematosus. They...
, protein C, protein S, antithrombin III deficiencies) is indicated.
Imaging studies are rarely required to diagnose VBI, but sometimes computed tomography (CT) is performed first. The CT is extremely sensitive in detecting hemorrhage. However, magnetic resonance imaging (MRI) is superior to the CT in detecting ischemic changes in the vertebrobasilar distribution. Magnetic resonance angiography (MRA) also can be used to identify vertebrobasilar stenoses or occlusions, but it can often overestimate the degree of stenosis, or wrongly show stenosis as an occlusion. Intracranial MRA is mostly sufficient to evaluate vertebrobasilar arteries, while extracranial vertebral arteries are better diagnosed using contrast-enhanced MRA, which is less dependent on flow phenomena and more accurate in evaluating stenosis.
CT angiography is also highly accurate in evaluation vertebrobasilar vessels, but ionizing radiation and use of nephrotoxic contrast media make it less suitable both in elderly with renal insufficiency and young adults because of radiation exposure. Moreover, vessel wall calcification and beam-hardening artifacts due to dense bones or metal fillings sometimes cause strong CT-image degradation.
Treatment
Patients should discuss with their physician possible causes for their VBI symptoms. As discussed above, postural changes, exercise, and dehydration are some of the likely culprits. Treatment usually involves lifestyle modifications. For example, if VBI is attributed mainly to postural changes, patients are advised to slowly rise to standing position after sitting for a long period of time. An appropriate exercise regimen for each patient can also be designed in order to avoid the excessive pooling of blood in the legs. Dehydrated patients are often advised to increase their water intake, especially in hot, dry climates. Finally, when applicable, patients are often advised to stop smoking and to control their hypertension, diabetes, and cholesterol level.In the event that a patient suffers a “drop attack,” and especially for the elderly population, the most important action is to be evaluated for associated head or other injuries. To prevent drop attacks, patients are advised to “go to the ground” before the knees buckle and shortly after feeling dizzy or experiencing changes in vision. Patients should not be concerned about the social consequences of suddenly sitting on the floor, whether in the mall or sidewalk, as such actions are important in preventing serious injuries.
Sometimes, to prevent further occlusion of blood vessels, patients are started on an antiplatelet agent (aspirin, clopidogrel, or aspirin/dipyridamole) or sometimes an anticoagulant (warfarin) once hemorrhage has been excluded with imaging.
For treatment of vertebrobasilar stenosis due to atherosclerosis, researchers from Stanford University found that intracranial angioplasty can be performed with an annual stroke rate in the territory of treatment of 3.2% and 4.4% for all strokes, including periprocedural events. Randomized control trials need to be performed.