Subcortical dementia refers to a pattern of cognitive impairment that predominantly arises from dysfunction or disease affecting the structures beneath the cerebral cortex, such as the basal ganglia, thalamus, and white matter pathways.
Unlike cortical dementias, such as Alzheimer’s disease—which typically involve pronounced memory loss, language disturbance, and higher-level perceptual deficits—subcortical dementias are characterised by slowed thought processes (bradyphrenia), impaired attention, difficulties with executive functions, and mood or personality changes such as apathy and depression.
Memory problems often relate more to poor retrieval than to genuine forgetting, and language and visuospatial skills are relatively preserved, particularly in the early stages.
Subcortical dementia most commonly occurs in disorders like Parkinson’s disease, Huntington’s disease, and vascular cognitive impairment involving small vessel or white matter disease. Recognition of this dementia subtype is important, as its clinical course, associated neurological signs, and management strategies can differ significantly from those of cortical dementias.
Note however, that as a result of the brain’s interconnections, the categorisation of cortical versus sub-cortical is one of convenience and neuropsychological disorders and deficits do not typically fall wholly within one category.
