(See also Overview of Delirium and Dementia Overview of Delirium and Dementia Delirium (sometimes called acute confusional state) and dementia are the most common causes of cognitive impairment, although affective disorders (eg, depression) can also disrupt cognition... read more and Dementia Dementia Dementia is chronic, global, usually irreversible deterioration of cognition. Diagnosis is clinical; laboratory and imaging tests are usually used to identify treatable causes. Treatment is... read more .)
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 Alzheimer Disease Alzheimer disease causes progressive cognitive deterioration and is characterized by beta-amyloid deposits and neurofibrillary tangles in the cerebral cortex and subcortical gray matter. Diagnosis... read more .
Dementia Dementia Dementia is chronic, global, usually irreversible deterioration of cognition. Diagnosis is clinical; laboratory and imaging tests are usually used to identify treatable causes. Treatment is... read more should not be confused with delirium Delirium Delirium is an acute, transient, usually reversible, fluctuating disturbance in attention, cognition, and consciousness level. Causes include almost any disorder or drug. Diagnosis is clinical... read more , although cognition is disordered in both. The following helps distinguish them:
Dementia affects mainly memory, is typically caused by anatomic changes in the brain, has slower onset, and is generally irreversible.
Delirium affects mainly attention, is typically caused by acute illness or drug toxicity (sometimes life threatening), and is often reversible.
Other specific characteristics also help distinguish the 2 disorders (see table Differences Between Delirium and Dementia Differences Between Delirium and Dementia* Delirium (sometimes called acute confusional state) and dementia are the most common causes of cognitive impairment, although affective disorders (eg, depression) can also disrupt cognition... read more ).
Etiology of Vascular Dementia
Vascular dementia typically results from multiple small cerebral infarcts Ischemic Stroke Ischemic stroke is sudden neurologic deficits that result from focal cerebral ischemia associated with permanent brain infarction (eg, positive results on diffusion-weighted MRI). Common causes... read more (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:
Multiple lacunar infarction: Small blood vessels are affected. Multiple lacunar infarcts occur deep within hemispheric white and gray matter.
Multi-infarct dementia: Medium-sized blood vessels are affected.
Strategic single-infarct dementia: A single infarct occurs in a crucial area of the brain (eg, angular gyrus, thalamus).
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.
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 Symptoms and Signs Dementia is chronic, global, usually irreversible deterioration of cognition. Diagnosis is clinical; laboratory and imaging tests are usually used to identify treatable causes. Treatment is... read more (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:
Exaggeration of deep tendon reflexes
Extensor plantar response
Weakness of an extremity
Pseudobulbar palsy with pathologic laughing and crying
Other signs of extrapyramidal dysfunction
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
Generally similar to diagnosis of other dementias
Diagnosis of vascular dementia is similar to the diagnosis of other dementias Diagnosis Dementia is chronic, global, usually irreversible deterioration of cognition. Diagnosis is clinical; laboratory and imaging tests are usually used to identify treatable causes. Treatment is... read more . A general diagnosis of dementia Clinical criteria Dementia is chronic, global, usually irreversible deterioration of cognition. Diagnosis is clinical; laboratory and imaging tests are usually used to identify treatable causes. Treatment is... read more requires all of the following:
Cognitive or behavioral (neuropsychiatric) symptoms interfere with the ability to function at work or do usual daily activities.
These symptoms represent a decline from previous levels of functioning.
These symptoms are not explained by delirium or a major psychiatric disorder.
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 How to Assess Mental Status The patient’s attention span is assessed first; an inattentive patient cannot cooperate fully and hinders testing. Any hint of cognitive decline requires examination of mental status (Professional... read more or, if bedside testing is inconclusive, formal neuropsychologic testing Assessment of cognitive function Dementia is chronic, global, usually irreversible deterioration of cognition. Diagnosis is clinical; laboratory and imaging tests are usually used to identify treatable causes. Treatment is... read more .
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:
Evidence of brain infarcts
High Hachinski Ischemic Score
Clinical features characteristic of vascular dementia (eg, prominent executive dysfunction, mild or absent memory loss)
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 Evaluation Strokes are a heterogeneous group of disorders involving sudden, focal interruption of cerebral blood flow that causes neurologic deficit. Strokes can be Ischemic (80%), typically resulting... read more should be done.
CT and MRI may show
Bilateral multiple infarcts in the dominant hemisphere and limbic structures
Multiple lacunar strokes
Periventricular white-matter lesions extending into the deep white matter
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)
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 Modified Hachinski Ischemic Score Vascular dementia is acute or chronic cognitive deterioration due to diffuse or focal cerebral infarction that is most often related to cerebrovascular disease. (See also Overview of Delirium... read more ).
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.
Prognosis for Vascular Dementia
The 5-year mortality rate for patients with vascular dementia is 61%, which is higher than that for most forms of dementia, presumably because other atherosclerotic disorders coexist.
Treatment of Vascular Dementia
Safety and supportive measures
Management of vascular risk factors, including smoking cessation
Safety and supportive measures Treatment Dementia is chronic, global, usually irreversible deterioration of cognition. Diagnosis is clinical; laboratory and imaging tests are usually used to identify treatable causes. Treatment is... read more 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:
Blood pressure control
Regulation of plasma glucose (90 to 150 mg/dL)
Drugs, such as cholinesterase inhibitors Drugs to treat Alzheimer disease Alzheimer disease causes progressive cognitive deterioration and is characterized by beta-amyloid deposits and neurofibrillary tangles in the cerebral cortex and subcortical gray matter. Diagnosis... read more 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.
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 Durable power of attorney for health care Advance directives are legal documents that extend a person's control over health care decisions in the event that the person becomes incapacitated. They are called advance directives because... read more ) should be made. When these documents are signed, the patient’s capacity Capacity (Competence) and Incapacity Historically, “incapacity” was considered primarily a clinical finding, and “incompetency” was considered a legal finding. That distinction, at least in terminology, is no longer firmly recognized... read more 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 Palliative Care and Hospice Dying patients can have needs that differ from those of other patients. So that their needs can be met, dying patients must first be identified. Before death, patients tend to follow 1 of 3... read more may be more appropriate than highly aggressive interventions or hospital care.
Vascular dementia can occur as a series of discrete episodes (which may seem like a gradual decline) or in a single episode.
Focal neurologic signs may help differentiate vascular dementia from other dementias.
Confirm that dementia is vascular based on a history of stroke or neuroimaging findings that suggest a vascular cause.
Control vascular risk factors, and if Alzheimer disease could also be present, treat with cholinesterase inhibitors and memantine.