Binswanger's disease, also known as subcortical leukoencephalopathy and subcortical arteriosclerotic encephalopathy, 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 changes in mood. These changes encompass what are known as executive functions of the brain. It usually presents between 54 and 66 years of age, and the first symptoms are usually mental deterioration or stroke.
It was described by Otto Binswanger in 1894, and Alois Alzheimer first used the phrase "Binswanger's disease" in 1902. However, Jerzy Olszewski is credited with much of the modern-day investigation of this disease which began in 1962.
Signs and symptoms
Symptoms include mental deterioration, language disorder, transient ischemic attack, muscle ataxia, and impaired movements including change of walk, slowness of movements, and change in posture. These symptoms usually coincide with multiple falls, epilepsy, fainting, and uncontrollable bladder.
The histologic findings are diffuse, irregular loss of axons and myelin accompanied by widespread gliosis, tissue death due to an infarction or loss of blood supply to the brain, and changes in the plasticity of the arteries. The pathologic mechanism may be damage caused by severe atherosclerosis. The onset of this disease is typically between 54 and 66 years of age, and the first symptoms are usually mental deterioration or stroke. It has been shown that Binswanger's disease targets the vessels in this zone of the subcortex, but spares the microcirculation's vessels and capillaries which may be attributed to a difference between Alzheimer's and Binswanger's disease.
Psychological presentation
There is a difference between cortical and subcortical dementia. Cortical dementia is atrophy of the cortex which affects ‘higher’ functions such as memory, language, and semantic knowledge whereas subcortical dementia affects mental manipulation, forgetfulness, and personality/emotional changes. Binswanger's Disease has shown correlations with impairment in executive functions, but have normal episodic or declarative memory. Executive functions are brain processes that are responsible for planning, cognitive flexibility, abstract thinking, rule acquisition, initiating appropriate actions and inhibiting inappropriate actions, and selecting relevant sensory information. There have been many studies done comparing the mental deterioration of Binswanger patients and Alzheimer patients. It has been found in the Graphical Sequence Test that Binswanger patients have hyperkinetic perseveration errors which cause the patients to repeat motion even when not asked whereas Alzheimer patients have semantic perseveration because when asked to write a word they will instead draw an image depicting the word.
Diagnosis
Binswanger's disease can usually be diagnosed with a CT scan, magnetic resonance imaging, and proton magnetic resonance spectrography in addition to clinical examination. Indications include infarctions, lesions, or loss of intensity of central white matter and enlargement of ventricles, and leukoaraiosis. A mini–mental state examination has been created to quickly assess cognitive impairment and serves as a screening test for dementia across different cultures.
Imaging
Leukoaraiosis refers to the imaging finding of white matter changes that are common in Binswanger disease. However, leukoaraiosis can be found in many different diseases and even in normal patients, especially in people older than 65 years of age.
Other researchers have begun using computers to calculate the percentage of white matter atrophy by counting the hyper-intense pixels of the magnetic resonance images. These and similar reports show a correlation between the amount of white matter alterations and the decline of psychomotor functions, reduced performance on attention and executive control. One type of technology is called susceptibility weighted imaging (SWI) which is a magnetic resonance technique which has an unusually high degree of sensitivity and can better detect white matter alterations.
Management
Binswanger's disease has no cure and has been shown to be the most severe impairment of all of the vascular dementias.
History
Binswanger in 1894 was the first to claim that white matter atrophy caused by 'vascular insufficiency' can result in dementia. He described a patient who had slow progression of dementia as well as subcortical white matter atrophy, ventricle enlargement, aphasia, hemianopsia, and hemiparesis. Yet again, in 1974 the term multi-infarct dementia was coined and all vascular dementia was grouped into one category. Because of this, the specific names of these types of this dementia, including Binswanger's disease were lost.
The complicated history of Binswanger's disease and that it was overlooked as a disease for many years means some patients may have been misdiagnosed with Alzheimer's disease.