A 62-year-old male is brought by his family for personality change. He was formerly polite and conscientious but now makes sexually inappropriate comments to strangers, shoplifts small items, has poor hygiene, and laughs incongruously. His episodic memory and visuospatial functions are preserved on testing. MRI shows prominent frontal and anterior temporal atrophy. What is the most likely diagnosis?
- A Alzheimer's disease
- B Behavioural variant Frontotemporal Dementia (bvFTD) ✓
- C Lewy body dementia
- D Huntington's disease
Explanation
Behavioural variant FTD (bvFTD) presents primarily with changes in personality, social behaviour, and executive function rather than memory loss. Diagnostic features include early disinhibition (sexual inappropriateness, shoplifting), apathy, loss of empathy/sympathy, perseverative/stereotyped behaviours, hyperorality, and executive dysfunction — all with relative sparing of episodic memory and visuospatial functions (preserved initially). MRI/CT shows frontal and anterior temporal atrophy. The median age of onset is 50–65 years. In contrast, Alzheimer's disease primarily affects episodic memory, and Lewy body dementia features fluctuating cognition, parkinsonism, and visual hallucinations.
Reference: Kaplan & Sadock's Synopsis of Psychiatry, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.