(See also Overview of Delirium and Dementia and Dementia.)
Dementia is chronic, global, usually irreversible deterioration of cognition.
Vascular dementia is the 2nd most common cause of dementia among older people. It is more common among men and usually begins after age 70. It occurs more often in people who have vascular risk factors (eg, hypertension, diabetes mellitus, hyperlipidemia, smoking) and in those who have had several strokes. Many people have both vascular dementia and Alzheimer disease.
Dementia should not be confused with delirium, although cognition is disordered in both. The following helps distinguish them:
Other specific characteristics also help distinguish the 2 disorders (see table Differences Between Delirium and Dementia).
Etiology of Vascular Dementia
Vascular dementia typically results from multiple small cerebral infarcts (or sometimes hemorrhages). Although each infarct may be only minimally symptomatic in itself, the combination of multiple small infarcts can cause enough neuronal or axonal loss to impair brain function.
Vascular dementias include the following:
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Multiple lacunar infarction: Small blood vessels are affected. Multiple lacunar infarcts occur deep within hemispheric white and gray matter.
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Multi-infarct dementia: Medium-sized blood vessels are affected.
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Strategic single-infarct dementia: A single infarct occurs in a crucial area of the brain (eg, angular gyrus, thalamus).
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Binswanger dementia (subcortical arteriosclerotic encephalopathy): This uncommon variant of small-vessel dementia is associated with severe, poorly controlled hypertension and systemic vascular disease. It causes diffuse and irregular loss of axons and myelin with widespread gliosis, tissue death due to an infarction, or loss of blood supply to the white matter of the brain.
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Hereditary vascular dementia: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a cerebral small vessel disease caused by mutations in the NOTCH3 (NOTCH receptor 3) gene, which codes for a transmembrane receptor located on vascular smooth muscle cells. Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is also a small vessel disease; it is caused by mutations in the HTRA1 gene.
Symptoms and Signs of Vascular Dementia
Symptoms and signs of vascular dementia are similar to those of other dementias (eg, memory loss, impaired executive function, difficulty initiating actions or tasks, slowed thinking, personality and mood changes, language deficits). However, compared with Alzheimer disease, vascular dementia tends to cause memory loss later and to affect executive function earlier. Also, symptoms can vary depending on where the infarcts occur.
Unlike other dementias, multiple-infarct dementia tends to progress in discrete steps; each episode is accompanied by intellectual decline, sometimes followed by modest recovery. Subcortical vascular dementia caused by small-vessel ischemic damage (which includes multiple lacunar infarction and Binswanger dementia) tends to cause small, incremental deficits; thus, the decline appears to be gradual.
As the disease progresses, focal neurologic deficits often develop:
Cognitive loss may be focal. For example, short-term memory may be less affected than in other dementias. Because loss may be focal, patients may retain more aspects of mental function. Thus, they may be more aware of their deficits, and depression may be more common than in other dementias.
Patients with CADASIL commonly present with cognitive impairment, migraine headaches, and/or stroke. CARASIL can cause alopecia and spondylosis. Age at onset varies.
Diagnosis of Vascular Dementia
Diagnosis of vascular dementia is similar to the diagnosis of other dementias. A general diagnosis of dementia requires all of the following:
Evaluation of cognitive function involves taking a history from the patient and from someone who knows the patient plus doing a bedside mental status examination or, if bedside testing is inconclusive, formal neuropsychologic testing.
Differentiation of vascular dementia from other dementias is based on clinical judgment. Factors that suggest vascular dementia (or Alzheimer disease with cerebrovascular disease) include the following:
Confirmation of vascular dementia requires a history of stroke or evidence of a vascular cause for dementia detected by neuroimaging. If focal neurologic signs or evidence of cerebrovascular disease is present, a thorough evaluation for stroke should be done.
CT and MRI may show
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Bilateral multiple infarcts in the dominant hemisphere and limbic structures
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Multiple lacunar strokes
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Periventricular white-matter lesions extending into the deep white matter
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In Binswanger dementia, leukoencephalopathy in the cerebrum semiovale adjacent to the cortex, often with multiple lacunae affecting structures deep in the gray matter (eg, basal ganglia, thalamic nuclei)
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In CADASIL and CARASIL, diffuse white matter hyperintensities with ischemic lesions in subcortical regions, including characteristic involvement of the anterior temporal lobe
The Hachinski Ischemic Score is sometimes used to help differentiate vascular dementia from Alzheimer disease (see table Modified Hachinski Ischemic Score).
The diagnosis of CADASIL and CARASIL can be confirmed by genetic tests, which identify characteristic mutations of the NOTCH3 gene for CADASIL and HTRA1 gene for CARASIL. Sometimes a skin biopsy can be done instead to confirm the diagnosis of CADASIL.
Modified Hachinski Ischemic Score
Feature |
Points* |
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Abrupt onset of symptoms |
2 |
|
Stepwise deterioration (eg, decline-stability-decline) |
1 |
|
Fluctuating course |
2 |
|
Nocturnal confusion |
1 |
|
Personality relatively preserved |
1 |
|
Depression |
1 |
|
Somatic complaints (eg, body aches, chest pain) |
1 |
|
Emotional lability |
1 |
|
History or presence of hypertension |
1 |
|
History of stroke |
2 |
|
Evidence of coexisting atherosclerosis (eg, PAD, MI) |
1 |
|
Focal neurologic symptoms (eg, hemiparesis, homonymous hemianopia, aphasia) |
2 |
|
Focal neurologic signs (eg, unilateral weakness, sensory loss, asymmetric reflexes, Babinski sign) |
2 |
|
* Total score is determined: |
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MI = myocardial infarction; PAD = peripheral arterial disease. |
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Adapted from Hachinski VC, Iliff LD, Zilhka E, et al: Cerebral blood flow in dementia. Arch Neurol 32 (9):632-637, 1975. |
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Prognosis of Vascular Dementia
Treatment of Vascular Dementia
Safety and supportive measures for vascular dementia are similar to those of other dementias. For example, the environment should be bright, cheerful, and familiar, and it should be designed to reinforce orientation (eg, placement of large clocks and calendars in the room). Measures to ensure patient safety (eg, signal monitoring systems for patients who wander) should be implemented.
Troublesome symptoms can be treated.
Managing vascular risk factors (eg, hypertension, diabetes, hyperlipidemia) may slow the progression of vascular dementia and help prevent future strokes, which could cause more cognitive impairment. Management includes the following:
Drugs, such as cholinesterase inhibitors and memantine, may be helpful if Alzheimer disease could also be present. Cholinesterase inhibitors may improve cognitive function. Memantine, an NMDA (N-methyl-d-aspartate) antagonist, may help slow the loss of cognitive function in patients with moderate to severe dementia and may be synergistic when used with a cholinesterase inhibitor.
However, efficacy of cholinesterase inhibitors and memantine is uncertain in vascular dementia. Nonetheless, a trial of these drugs is reasonable because older patients with vascular dementia may also have Alzheimer disease.
End-of-life issues
Because insight and judgment deteriorate in patients with dementia, appointment of a family member, guardian, or lawyer to oversee finances may be necessary. Early in dementia, before the patient is incapacitated, the patient’s wishes about care should be clarified, and financial and legal arrangements (eg, durable power of attorney, durable power of attorney for health care) should be made. When these documents are signed, the patient’s capacity should be evaluated, and evaluation results recorded. Decisions about artificial feeding and treatment of acute disorders are best made before the need develops.
In advanced dementia, palliative measures may be more appropriate than highly aggressive interventions or hospital care.
Key Points about Vascular Dementia
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Vascular dementia can occur as a series of discrete episodes (which may seem like a gradual decline) or in a single episode.
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Focal neurologic signs may help differentiate vascular dementia from other dementias.
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Confirm that dementia is vascular based on a history of stroke or neuroimaging findings that suggest a vascular cause.
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Control vascular risk factors, and if Alzheimer disease could also be present, treat with cholinesterase inhibitors and memantine.
Drugs Mentioned In This Article
| Drug Name | Select Trade |
|---|---|
memantine |
NAMENDA |
