Cognition enhancers for the treatment of dementia

Dementia is a broad term used to describe several chronic progressive neurological disorders that adversely affect higher mental functions including memory, language, behaviour, abstract thinking, comprehension, calculation, learning capacity and judgement. Alzheimer's disease is the most common form of dementia but other neurological conditions such as Parkinson's disease, cerebrovascular disease and chronic infections such as syphilis can also lead to the clinical syndrome of dementia. Initial investigations should always focus on finding any treatable cause for dementia such as HIV, structural lesions such as subdural haematomas or specific nutritional deficiency states such as that due to vitamin B12 and treated appropriately. Where no treatable or reversible aetiology is found, a referral to a specialist should be considered who may initiate further investigations including magnetic resonance imaging or perfusion single-photon emission computerised tomography scans of the brain, and sometimes cerebrospinal fluid examination or an electroencephalogram.