Early Onset Dementia:Subtypes and Neuropsychiatric Aspects

Early onset dementia (EOD) is the dementia occurring before 65 years of age. Major causes of EOD are Alzheimer's disease (AD), vascular dementia (VaD) and fronto temporal dementia (FTD) along with some reversible causes. We aimed to know 1) Clinical characteristics of EOD 2) Pattern of first presentation 3) Role head injury, smoking and alcohol abuse 4) Impact on activities of daily living (ADL) 5) Complications like delirium and psychosis. We collected data after evaluation of cognitively impaired patients during 2011 to 2013. Interpretation was done by using frequency distribution. Out of 280 patients 50 were diagnosed as EOD (18%). Males were 43/50 (86%) and females were 7/50 (14%). AD was main cause of EOD (38%) followed by VaD (34%) and FTD (14%). About 42% presented with behavioral and 38% with memory symptoms as first presentation while 20% had both. Alcohol abuse and smoking was seen in 46% and 42% respectively. 14% patients showed positive family history of EOD and history of head injury. Psychosis was seen in 34% and delirium in 14 % in the course of illness. VaD (76%) most commonly affected ADL followed by FTD (71%) and AD (68%). We concluded that 1) EOD was more prevalent in male.2) FTD commonly presented with behavioral while AD with memory problems as first presentation. 3) Alcohol abuse and head injury predisposed to MxD while smoking to VaD. 4) VaD most severely affected ADL followed by FTD and AD. 5) Delirium was frequent VaD while psychosis in AD.