Dementia, a syndrome of declining higher cognitive functioning, found in approximately 10 per cent of adults 65 years and older, and 50 per cent of adults older than 90 years. Alzheimer’s disease (AD) accounts for 50 to 80 per cent of all dementing illnesses. Vascular dementia comprises 15 to 20 per cent of dementia and in some clinico-pathological series is the second commonest form of dementia, often coexisting with Alzheimer’s disease. Other degenerative conditions such as Parkinson’s disease with dementia (PDD), dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD) account for 10–15% of dementia. Less than 10 per cent of dementias are caused by reversible conditions eg Vitamin B12 deficiency, hypothyroidism (1–3).