11th August 2024

Vascular dementia

Overview of vascular dementia

Vascular dementia is the second most common cause of dementia in older people. It is a dementia syndrome recognised as the decompensation of cognitive function resulting from the accumulation of vascular insults and can be considered on a spectrum of cognitive impairment of vascular aetiology.

The presentation is varied, and the affected domains and severity of cognitive deficits relate to the location and burden of cerebrovascular disease. Mechanisms of vascular insult include large vessel ischaemia resulting in discrete infarcts, small vessel disease of subcortical structures (basal ganglia, thalamus, brainstem), deep white matter disease (leukoaraiosis) and haemorrhage (cortical haemorrhage associated with cerebral amyloid angiopathy).

In contrast to Alzheimer’s disease, typically, executive and attention function is more affected than memory with earlier involvement of mobility and mood. Classically, a history of a stepwise progression is seen with repeated clinically significant vascular events, although sequential silent events will present with insidious cognitive decline. A mixed dementia syndrome with Alzheimer’s is common.

Diagnosis of vascular dementia

Diagnosis requires cognitive testing showing impairment in two or more domains and brain imaging demonstrating cerebrovascular disease with either history of cognitive symptoms related to vascular event(s) or cognitive impairment explained by the degree/pattern of disease seen on imaging.

Small vessel disease on MRI is seen as periventricular and subcortical white matter lesions, subcortical infarcts, and cerebral microbleeds (hypointense foci on T2-weighted sequences).

Management of vascular dementia

Antiplatelets and anticoagulation, respectively, are used as secondary prevention for arteriosclerotic and cardioembolic causes. Prevention is through modification of risk factors, which are hypertension, smoking, hypercholesterolaemia, diabetes and obesity; however, increasing age is the greatest risk factor.