2 Neuroscience2.13 Neurodegeneration

2.13.3 Vascular dementia

2 min read1 figure

Written by Resident Doctor Committee · Published

What vascular dementia is

  • Vascular dementia is ischaemic damage from infarcts, white matter loss and small vessel arteriopathy, and it is not a tauopathy.

  • Mixed vascular and degenerative pathology is common.

Stroke and transient ischaemic attack

  • Stroke and transient ischaemic attack are both focal deficits of vascular cause, and they differ only in whether the deficit outlasts 24 hours.

  • Early case fatality is higher after primary intracerebral haemorrhage than after cerebral infarction, so infarction carries the better prognosis.

Large and small vessel disease

Type

Cause

Course

Multi-infarct (large vessel, cortical)

Atheroma of the major cerebral arteries causes thrombosis and embolism, which produce cumulative territorial infarcts

Stepwise, with plateaus

Small vessel (subcortical)

Lacunes, white matter damage and arteriolosclerosis

Gradual

  • Small vessel disease causes a frontal subcortical syndrome of slowing, executive dysfunction, apathy and a short-stepped gait.

  • The Hachinski Ischaemic Score combines vascular history, course and neurological features: 7 or more suggests vascular disease, and 4 or less suggests degenerative disease.

CADASIL

  • CADASIL is an inherited subcortical small vessel disease that is autosomal dominant and caused by mutation in NOTCH3.

  • Patients may have migraine with aura, recurrent subcortical events, mood change and progressive cognitive decline.

  • Magnetic resonance imaging often shows changes in the anterior temporal white matter and the external capsule.

In CADASIL, look at the bright white matter at the front of both temporal lobes in the lower panels: anterior temporal involvement is the distribution that separates it from sporadic small vessel disease. Bohlega S, Al Shubili A, Edris A, Alreshaid A, Alkhairallah T, AlSous MW, Farah S, Abu-Amero KK., CC BY 2.0, via Wikimedia Commons

Prevention and treatment

  • Treating hypertension is the vascular risk factor intervention with randomised trial evidence that it reduces dementia (Syst-Eur, PROGRESS).

  • No drug specifically reverses established vascular dementia.

Normal pressure hydrocephalus

  • Normal pressure hydrocephalus is a treatable cause of dementia to consider whenever gait, continence and cognition change together.

  • Its triad is gait disturbance (the leading feature), urinary incontinence and cognitive impairment.

  • The ventricles enlarge and cause periventricular stretch, but intracranial pressure is not raised.

  • It is a communicating hydrocephalus: cerebrospinal fluid leaves the ventricles freely, and the fault lies in reabsorption.

Revision material for the MRCPsych examinations. Not clinical guidance, and not for use in patient care.