Subcortical dementia

Subcortical dementia is a type of dementia characterised by slowness of mental processing, forgetfulness, impaired cognition, apathy, and depression.^[1]

Disorders, such as CADASIL, that result in subcortical dementia have changes that involve primarily the thalamus, basal ganglia, and related brain-stem nuclei with relative sparing of the cerebral cortex. It affects arousal, attention, mood, motivation, language, memory, abstraction, and visuospatial skills. Subcortical dementia differs from other dementia such as Alzheimer's where prominent cerebral cortical involvement produces aphasia, amnesia, agnosia, and apraxia.^[1]

In most kinds of dementia there is widespread degeneration in the cerebral cortex – such as the plaques and tangles which are the hallmark of Alzheimer's disease. In other kinds of dementia, there is targeted damage to regions lying under the cortex, giving rise to the category known as "subcortical dementias".

As a general rule the earliest symptoms in "cortical" dementia include difficulty with high-level behaviors such as memory, language, problem-solving and reasoning – functions associated with the cerebral cortex.

However in "subcortical" dementia these high-level behaviours are less affected.^[2]

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