A 65-year-old male is brought to the outpatient clinic with one year illness characterized by marked forgetfulness, visual hallucinations, suspiciousness, personality decline, poor self care and progressive deterioration in his condition. His Mini Mental Status Examination (MMSE) score 21. His most likely diagnosis is:

Old age with history suggestive of a progressive impairment in memory, presence of behavioral and psychological symptoms (hallucinations, suspiciousness), poor self care and personality decline and a MMSE score <24, are all suggestive of dementia. DEMENTIA It is the progressive impairment of cognitive functions , in absence of disturbance of consciousness Symptoms- Cognitive impairments: 4As: Amnesia, Aphasia, Apraxia, Agnosia Behavioral & Psychological symptoms:Personality changes,Delusions and Hallucinations , Anxiety ,Depressive symptoms. Focal Neurological Deficit- Usually seen in vascular dementia