ABSTRACT
Patients with a diagnosis of human immunodeficiency virus (HIV) infection may develop a dementia in the course of the disease. Once a provisional diagnosis of dementia has been made, the clinician needs to clarify the type of dementia from which the person is suffering. Dementia was classified traditionally as pre-senile or senile, based on age of onset. The age of onset may be helpful in deciding on the aetiology, but many of the causes of dementia are found in both age groups, making this traditional approach to classification relatively redundant. A dementia may develop in the course of established Parkinson’s disease. Alcohol is known to be neurotoxic, but the existence of ‘alcoholic dementia’ as a distinct entity is doubtful. Many patients diagnosed with alcoholic dementia actually have Korsakoff’s syndrome. Subcortical dementias include those associated with Huntington’s disease, Parkinson’s disease and HIV. Dementia may dominate the clinical picture but there may be concomitant physical problems, e.g. dysarthria and gait disorders.
