Vascular dementia is the second most common form of dementia after Alzheimer disease (AD). The condition is not a single disease; it is a group of syndromes relating to different vascular mechanisms. Vascular dementia is preventable; therefore, early detection and an accurate diagnosis are important.
Patients who have had a stroke are at increased risk for vascular dementia. Recently, vascular lesions have been thought to play a role in AD.
As early as 1899, arteriosclerosis and senile dementia were described as different syndromes. In 1969, Mayer-Gross et al described this syndrome and reported that hypertension is the cause in approximately 50% of patients. In 1974, Hachinski et al coined the term multi-infarct dementia. In 1985, Loeb used the broader term vascular dementia. Recently, Bowler and Hachinski introduced a new term, vascular cognitive impairment.
Many subtypes of vascular dementia have been described to date. The spectrum includes:
- mild vascular cognitive impairment
- multi-infarct dementia
- vascular dementia due to a strategic single infarct
- vascular dementia due to lacunar lesions
- vascular dementia due to hemorrhagic lesions
- Binswanger disease, and mixed dementia ( combination of AD and vascular dementia ).
Vascular dementia is sometimes further classified as cortical or subcortical dementia.
Vascular disease produces either focal or diffuse effects on the brain and causes cognitive decline. Focal cerebrovascular disease occurs secondary to thrombotic or embolic vascular occlusions. Common areas of the brain associated with cognitive decline are the white matter of the cerebral hemispheres and the deep gray nuclei, especially the striatum and the thalamus. Hypertension is the major cause of diffuse disease, and in many patients, both focal and diffuse disease are observed together. The 3 most common mechanisms of vascular dementia are multiple cortical infarcts, a strategic single infarct, and small vessel disease.
Mild vascular cognitive impairment can occur in elderly persons. It is associated with cognitive decline that is worse than expected for age and educational level, but the effects do not meet the criteria for dementia and are not associated with vascular risk factors or evidence of silent strokes or extensive white matter infarcts on CT scanning. These people have subjective and objective evidence of memory problems, but their daily functional living skills are within normal limits.
In multi-infarct dementia, the combined effects of different infarcts produce cognitive decline by affecting the neural nets.
In single-infarct dementia, different areas in the brain can be affected, which may result in significant impairment in cognition. This may be observed in cases of anterior cerebral artery infarct, parietal lobe infarcts, thalamic infarction, and singular gyrus infarction.
Small vessel disease affects all the small vessels of the brain and produces 2 major syndromes, Binswanger disease and lacunar state. Small vessel disease results in arterial wall changes, expansion of the Virchow-Robin spaces, and perivascular parenchymal rarefaction and gliosis.
Lacunar disease is due to small vessel occlusions and produces small cavitary lesions within the brain parenchyma secondary to occlusion of small penetrating arterial branches. These lacunae are found more typically in the internal capsule, deep gray nuclei, and white matter. Lacunar state is a condition in which numerous lacunae, which indicate widespread severe small vessel disease, are present.
Binswanger disease (also known as subcortical leukoencephalopathy) is due to diffuse white matter disease. In Binswanger disease, vascular changes observed are fibrohyalinosis of the small arteries and fibrinoid necrosis of the larger vessels inside the brain.
In cerebral amyloid angiopathy–associated vasculopathy, aneurysm formation and stenosis in the leptomeningeal and cortical vessels cause damage to the subcortical white matter. In hereditary cystatin-C amyloid angiopathy, patients have recurrent cerebral hemorrhages before age 40 years that can lead to dementia.
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy is a rare autosomal dominant condition localized to chromosome arm 19q12 that affects small vessels supplying the deep white matter. Pathologically, multiple small infarcts are observed in the white matter, thalamus, basal ganglia, and pons.
Other less common syndromes may lead to vascular dementia. Rare arteriopathies such as inflammatory arteriopathy (eg, polyarteritis nodosa, temporal arteritis) and noninflammatory arteriopathy (eg, moyamoya disease, fibromuscular dysplasia) can cause multiple infarcts and can lead to vascular dementia. Hypoperfusion due to large vessel or cardiac disease can affect the watershed areas of the brain and lead to vascular dementia.
Mixed dementia is diagnosed when patients have evidence of Alzheimer dementia and cerebrovascular disease, either clinically or based on neuroimaging evidence of ischemic lesions. Growing evidence indicates that vascular dementia and Alzheimer dementia often coexist, especially in older patients with dementia.
Autopsy studies have shown the association between AD and vascular lesions. Several recent studies also suggest that the risk of developing AD is increased when a patient is exposed to vascular risk factors such as hypertension, diabetes mellitus, peripheral arterial disease, and smoking, which usually are associated with cerebrovascular disease and vascular dementia. Recent evidence suggests that the vascular processes in both disorders may mutually induce each other. Apolipoprotein E may play a role in AD and vascular dementia. Apolipoprotein E-IV also increases the risk of dementia in stroke survivors and is a strong risk factor for the development of cerebral amyloid angiopathy in patients with AD. In elderly individuals, many cases of dementia may be caused by the cumulative effect of cerebrovascular and Alzheimer pathology.
- Internationally: Vascular dementia is the second most common cause of dementia in the United States and Europe, but it is the most common form in some parts of Asia. The prevalence rate of vascular dementia is 1.5% in Western countries and approximately 2.2% in Japan. In Japan, it accounts for 50% of all dementias that occur in individuals older than 65 years. In Europe, vascular dementia and mixed dementia account for approximately 20% and 40% of cases, respectively. In Latin America, 15% of all dementias are vascular. In community-based studies in Australia, the prevalence rate for vascular and mixed dementia is 13% and 28%, respectively. The prevalence rate of dementia is 9 times higher in patients who have had a stroke than in controls. One year after a stroke, 25% of patients develop new-onset dementia. Within 4 years following a stroke, the relative risk of incident dementia is 5.5%.
- In patients with dementia who have had a stroke, the increase in mortality is significant. The 5-year survival rate is 39% for patients with vascular dementia compared with 75% for age-matched controls.
- Vascular dementia is associated with a higher mortality rate than AD, presumably because of the coexistence of other atherosclerotic diseases.
- The prevalence of vascular dementia is higher in men than in women.
- Incidence increases with age.
History: Cognitive impairment, acutely or subacutely, after an acute neurologic event with a stepwise progression is a typical history suggestive of vascular dementia. However, this classic history is usually observed with multi-infarct dementia and may not be observed with lacunar state.
- The average age of onset is between the fourth and seventh decades of life, and 80% of patients have a history of hypertension.
- Patients also show progressive motor, cognitive, mood, and behavioral changes over a period of 5-10 years. Mood and behavioral changes are observed early and, in some patients, may be the presenting feature.
- Patients may be apathetic or abulic.
- Intellectual deficits are also observed early in the disease, and patients are frequently described as disoriented, having memory deficits, inattentive, and vague.
- Patients with Binswanger dementia often have early-onset urinary incontinence and gait disturbances.
- Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy
- The onset of the disease occurs between the third and fourth decades of life.
- The clinical picture is similar to Binswanger disease but without a history of hypertension and risk factors for cerebrovascular disease.
- Vascular dementia in general
- Patients with vascular dementia commonly have mood and behavioral changes.
- Severe depression is more common in persons with vascular dementia than in those with AD.
- In some patients with lacunar state and Binswanger disease, such problems may be more prominent than intellectual deficits.
- Even psychotic symptoms, particularly delusions, have been described in patients with vascular dementia.
Physical: A commonly used cognitive screening tool is the Folstein Mini-Mental State Examination. Patchy defects are present in persons with vascular dementia. The deficits are global in persons with Alzheimer dementia.
- The Folstein Mini-Mental State Examination is as follows:
- Orientation: First, ask the patient the date, day, month, year, and season. The maximum score is 5. Second, ask the patient their current location, ie, facility, floor, town, state, and country. The maximum score is 5.
- Registration: Name 3 objects (eg, ball, flag, door), and ask the patient to repeat them. The maximum score is 5.
- Attention: Ask the patient to spell the word “world” backwards or to subtract 7 from 100 serially backwards (stop after 5 answers). The maximum score is 5.
- Recall: Ask the patient to remember the 3 objects from the Registration portion of the test. The maximum score is 3.
- Ask the patient to identify a pencil and a watch. The maximum score is 2.
- Ask the patient to repeat the phrase "no ifs, ands, or buts." The maximum score is 1.
- Ask the patient to follow a 3-step command. The maximum score is 3.
- Ask the patient to read and obey the phrase “close your eyes.” The maximum score is 1.
- Ask the patient to write a sentence. The maximum score is 1.
- Ask the patient to copy a set of interlocking pentagons. The maximum score is 1.
- Scoring: The maximum score possible is 30. Generally, any score less than 24 is considered abnormal, but the cutoff varies with the patient's level of education. Because the results for this test can vary over time, and for some people results can vary during the day, record when (ie, the time and date) this test was performed.
- Several specific diagnostic criteria can be used to diagnose vascular dementia, including the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria, the International Classification of Diseases, Tenth Edition criteria, the National Institute of Neurological Disorders and Stroke-Association International pour la Recherché at L'Enseignement en Neurosciences (NINDS-AIREN) criteria, the Alzheimer's Disease Diagnostic and Treatment Center criteria, and the Hachinski ischemic score.
- The DSM-IV criteria have good sensitivity but low specificity. A summary of the DSM-IV diagnostic criteria is as follows:
- The patient has developed multiple cognitive deficits manifesting as both (1) memory impairment and (2) one or more of the following cognitive disturbances: aphasia, apraxia, agnosia, and disturbance in executive functioning.
- The cognitive deficits in the above criteria cause significant impairment in social or occupational functioning and represent a significant decline from the previous level of functioning.
- Focal neurologic signs and symptoms or radiologic evidence indicative of cerebrovascular disease are present that are judged to be etiologically related to the dementia.
- The deficits do not occur exclusively during the course of delirium.
- The NINDS-AIREN criteria are the most specific of all available criteria and are used most commonly in research. They provide 3 levels of certainty: definite, probable, and possible.
- Lateralizing signs such as hemiparesis, bradykinesia, hyperreflexia, extensor plantar reflexes, ataxia, pseudobulbar palsy, and gait and swallowing difficulties may be observed.
- Neuropsychological testing is as follows:
- Patients with vascular dementia have patchy neuropsychological deficits. With vascular dementia, patients have better free recall and fewer recall intrusions compared with patients with AD. Apathy early in the disease is more suggestive of vascular dementia because it usually occurs in the later stages of AD.
- Patients with vascular dementia have poor verbal fluency and more perseverative behavior compared with patients with AD. They may even have other signs of executive dysfunction such as cognitive slowing, difficulty in shifting sets, and problems with abstraction. Commonly used mental status tests include the Folstein Mini-Mental State Examination and the Cognitive Abilities Screening Instrument.
- Neuropsychological findings vary with the site and severity of cerebrovascular disease.
- For patients with single or multiple large infarcts, deficits correlate with the site and extent of the infarct.
- In patients with extensive deep white matter disease, impairments may be observed in tests of psychomotor speed, dexterity, executive function, and motor aspects of speech (eg, dysarthria, reduced verbal output).
- Risk factors for vascular dementia include hypertension, smoking, hypercholesterolemia, diabetes mellitus, and cardiovascular and cerebrovascular disease.
Other Problems to be Considered:
Normal pressure hydrocephalus
Lewy body dementia
Patients with AD have early language and visuospatial deficits. The deficits in short-term memory are severe, and clues do not help in retrieving information. The onset of the disease is gradual, with a slow progression. Usually, no motor findings are present until the middle or late stages of the disease.
Patients with vascular dementia have patchy cognitive impairment, often with focal neurologic signs and symptoms. Onset may be abrupt, with a stepwise decline.
Patients with Parkinson dementia have cognitive slowing with extrapyramidal signs such as rigidity, bradykinesia, tremor, and gait disturbances. Usually, dementia is seen in later stages of the disease.
Patients with dementia due to head trauma have memory impairment, and other cognitive deficits associated with a history of head trauma occur. The physical findings depend on the location of injury. Usually, it is not progressive unless the person has a history of repeated head trauma (eg, dementia pugilistica).
Patients with HIV dementia have cognitive changes with neurologic signs and a positive result from an HIV test.
Patients with Pick disease have memory problems, personality changes, and deterioration of social skills. Onset is usually between the fifth and sixth decades of life. Upon physical examination, the patient has frontal release signs such as snout and grasp reflex.
Huntington disease is an autosomal dominant disease with an onset of cognitive changes as early as the third decade of life, with physical signs of choreoathetosis.
In Creutzfeldt-Jakob disease, onset is between the fourth and sixth decades of life and is associated with signs such as myoclonus, seizures, and ataxia. A rapid progression is typical.
Patients with Lewy body dementia have recurrent visual hallucinations, fluctuating cognitive impairment, and parkinsonism features. Also, the frequency of adverse reactions to antipsychotic medications is high.
In the case of cognitive symptoms secondary to depression, the onset is acute compared with the insidious onset in most types of dementia. The term pseudodementia has been used to describe the condition when cognitive symptoms are prominent. The current and more accurate name for this state is dementia of depression. Patients with depression usually report their cognitive difficulties, which is unusual for patients with dementia. Patients with depression tend to state that they do not know the answers to questions, and they appear to not try very hard during neuropsychological evaluations. Mood symptoms are prominent in patients with dementia of depression.
- Laboratory tests should be performed to rule out other causes of dementia. These tests should routinely include a CBC count, erythrocyte sedimentation rate, glucose level, renal and liver function tests, serologic tests for syphilis, vitamin B-12 and red blood cell folate levels, and thyroid function tests.
- In selected patients, optional tests include HIV serology testing, lupus anticoagulant testing, antiphospholipid antibody testing, antinuclear antibody testing, and antineutrophil cytoplasmic antibody testing.
- Neuroimaging studies may include CT brain scanning and MRI of the brain.
- The absence of cerebrovascular lesions on CT scanning or MRI is evidence against vascular etiology.
- The features on CT scanning or MRI that are suggestive of vascular dementia are bilateral multiple infarcts located in the dominant hemisphere and limbic structures, multiple lacunar strokes, or periventricular white matter lesions extending into the deep white matter.
- Functional imaging studies include the following:
- According to a 2000 study by Nagata et al, positron emission tomography may be useful for differentiating vascular dementia from AD. Hypoperfusion and hypometabolism can be observed in the frontal lobe, including the cingulate and superior frontal gyri, in patients with vascular dementia; a parietotemporal pattern is observed in patients with AD.
- Starkstein et al in 1996 and other authors have demonstrated that single-photon emission CT scanning produce similar findings.
- Cerebral angiography is not performed routinely during the evaluation of vascular dementia, but it is performed before carotid artery surgery. It also is useful in cases of possible cerebral vasculitis; cerebral vessels can demonstrate beading.
- Tests that may be useful for evaluation of stroke and in certain cases of vascular dementia include the following:
- Holter monitoring
- Carotid duplex Doppler scanning
Medical Care: The mainstay of management of vascular dementia is the prevention of new strokes. This includes administering antiplatelet drugs and controlling major vascular risk factors. Aspirin has also been found to slow the progression of vascular dementia.
- Recent guidelines from the American Psychiatric Association provide both treatment principles and possible specific therapies.
- Drug treatment is primarily used to prevent further worsening of vascular dementia by treating the underlying disease such as hypertension and diabetes mellitus. Antiplatelet agents are indicated.
- Pentoxifylline and, to a more limited extent, ergoloid mesylates (Hydergine), may be useful for increasing cerebral blood flow. In the European Pentoxifylline Multi-Infarct Dementia Study, which is a double-blinded, placebo-controlled, multicenter study, treatment with pentoxifylline was found to be beneficial for patients with multi-infarct dementia. Significant improvement was observed in the scales used for assessing intellectual and cognitive function.
- Neuroprotective drugs such as nimodipine, propentofylline, and posatirelin are currently under study and may be useful for vascular dementia.
- Increasing evidence supports the involvement of the cholinergic system in vascular dementia, similar to that seen in Alzheimer dementia. However, no cholinesterase inhibitors have been approved to date for the treatment of vascular dementia, despite positive results in clinical trials with this medication.
- The general management of dementia includes appropriate referral to community services, judgment and decision-making regarding legal and ethical issues (eg, driving, competency, advance directives), and consideration of caregiver stress.
- In the Rotterdam study, an increased risk of vascular dementia was associated with total fat intake, whereas fish consumption was inversely related to dementia.
- Low levels of folate, vitamin B-6, and vitamin B-12 are associated with increased homocysteine levels, a risk factor for stroke.
Synonyms and related keywords: arteriosclerotic dementia, atherosclerotic disease, dementia due to vascular disease, multiinfarct dementia, multi-infarct dementia, vascular cognitive impairment, Alzheimer disease, AD, Alzheimer's disease, cognitive dementia, senility, stroke, old age dementia, senile dementia, Binswanger disease, Binswanger's disease, mixed dementia, lacunar lesions, cortical dementia, subcortical dementia, cognitive decline, subcortical leukoencephalopathy, Binswanger dementia, Alzheimer dementia, cerebrovascular disease, thrombotic vascular occlusions, embolic vascular occlusions, hypertension, multiple cortical infarct, strategic single infarct, small vessel disease, single-infarct dementia, anterior cerebral artery infarct, parietal lobe infarcts, thalamic infarction, singular gyrus infarction, subcortical leukoencephalopathy, cerebral amyloid angiopathy–associated vasculopathy, hereditary cystatin-C amyloid angiopathy, recurrent cerebral hemorrhages, inflammatory arteriopathy, polyarteritis nodosa, temporal arteritis, noninflammatory arteriopathy, moyamoya disease, fibromuscular dysplasia, apolipoprotein E, apolipoprotein E-IV, cognitive impairment, urinary incontinence, gait disturbances, cerebral autosomal dominant arteriopathy, subcortical infarcts, depression, delusions, Folstein Mini-Mental State Examination, aphasia, apraxia, agnosia, smoking, hypercholesterolemia, diabetes, cardiovascular disease.