A 58-year-old man is brought by his spouse because over the past year he has started behaving inappropriately, making rude comments and showing episodes of irritability. He has also forgotten a few important personal events, but his overall memory seems fairly intact. His medical background includes diabetes, high blood pressure, and dyslipidaemia. On examination, he has reduced facial expression but no focal neurological deficits. What is the most likely diagnosis?
a. Alzheimer-type dementia
b. Rapid prion-related dementia
c. Lewy body-associated dementia
d. Frontotemporal degeneration
e. Multi-infarct cognitive decline
Answer:
Frontotemporal degeneration
Detailed Explanation:
This is a classic behavioral variant frontotemporal dementia (FTD) presentation.
Key clinical clues:
- Early personality and behavioural changes → aggression, disinhibition, inappropriate remarks
- Relatively preserved memory (early stage)
- Onset typically <65 years (but can occur slightly later)
- Social misconduct > cognitive decline initially
This strongly contrasts with other dementias:
Alzheimer’s disease
- Early prominent episodic memory loss
- Behavioural issues occur later
Creutzfeldt-Jakob disease
- Rapidly progressive dementia
- Myoclonus, ataxia → not seen here
Dementia with Lewy bodies
- Visual hallucinations
- Fluctuating cognition
- Parkinsonism (masked facies alone is insufficient)
Vascular dementia
- Stepwise decline
- Focal neurological deficits
- Executive dysfunction > personality disinhibition
High-Yield Clinical Pattern Recognition (Exam Gold):
- Disinhibition + personality change + preserved memory → FTD
- Memory loss first → Alzheimer’s
- Hallucinations + Parkinsonism → Lewy body
- Stepwise decline → Vascular
- Rapid decline → CJD
Cheat Sheet (Ultra-fast revision)
Frontotemporal Dementia (FTD):
- Age: <65 years (usually)
- Early: Behavioural change
- Memory: relatively preserved early
- Features:
- Disinhibition
- Aggression
- Hyperorality
- Apathy
- Pathology: Tau (Pick bodies)
- Imaging: Frontal/temporal atrophy
- Treatment: No role for AChE inhibitors
Flashcards
Q1: Earliest symptom in frontotemporal dementia?
A: Behavioural/personality change
Explanation: Frontal lobe involvement → disinhibition before memory loss
Q2: Memory pattern in FTD?
A: Relatively preserved early
Explanation: Temporal/hippocampal involvement occurs later
Q3: Key pathological finding in Pick’s disease?
A: Pick bodies (tau protein inclusions)
Q4: Which dementia presents with hallucinations early?
A: Dementia with Lewy bodies
Q5: Stepwise cognitive decline suggests?
A: Vascular dementia
MCQs (High-yield + challenging)
MCQ 1
A 55-year-old executive develops socially inappropriate behaviour and overeating. Memory is intact. Most likely diagnosis?
a. Alzheimer’s disease
b. Vascular dementia
c. Frontotemporal dementia
d. Lewy body dementia
Answer: c
Explanation: Behavioural disinhibition with preserved memory = FTD
MCQ 2
Which feature is least likely in frontotemporal dementia?
a. Disinhibition
b. Hyperorality
c. Early severe memory loss
d. Apathy
Answer: c
Explanation: Memory is preserved early in FTD
MCQ 3
Which pathology is associated with Pick’s disease?
a. Amyloid plaques
b. Lewy bodies
c. Tau inclusions
d. Prion proteins
Answer: c
Explanation: Pick bodies are tau protein aggregates
MCQ 4
A patient has fluctuating cognition, visual hallucinations, and Parkinsonism. Diagnosis?
a. Alzheimer’s
b. Lewy body dementia
c. FTD
d. Vascular dementia
Answer: b
Explanation: Classic Lewy body triad
MCQ 5
Which of the following is false regarding vascular dementia?
a. Stepwise decline
b. Associated with vascular risk factors
c. Early personality disinhibition is typical
d. Focal neurological signs may occur
Answer: c
Explanation: Early disinhibition is FTD, not vascular dementia
MCQ 6
Rapidly progressive dementia with myoclonus suggests:
a. Alzheimer’s
b. FTD
c. CJD
d. Lewy body dementia
Answer: c
Explanation: CJD = rapid progression + myoclonus
MCQ 7
Which drug class is NOT useful in FTD?
a. SSRIs
b. Antipsychotics (carefully)
c. Acetylcholinesterase inhibitors
d. Behavioural therapy
Answer: c
Explanation: AChE inhibitors not recommended in FTD
Summary for Quick Exam Revision
Frontotemporal dementia is a neurodegenerative disorder characterized by early behavioural and personality changes with relatively preserved memory in the initial stages. It typically presents before the age of 65 and is associated with disinhibition, aggression, apathy, and socially inappropriate behaviour due to frontal lobe involvement. Unlike Alzheimer’s disease, where memory impairment is the earliest feature, FTD primarily affects executive and behavioural functions first. Lewy body dementia is distinguished by visual hallucinations, fluctuating cognition, and Parkinsonian features, while vascular dementia presents with a stepwise decline and focal neurological deficits. Creutzfeldt-Jakob disease should be suspected in rapidly progressive dementia with myoclonus. Pathologically, FTD (especially Pick’s disease) is associated with tau protein inclusions called Pick bodies. Imaging often shows frontal and temporal lobe atrophy. Importantly, acetylcholinesterase inhibitors are not beneficial in FTD, making accurate differentiation crucial for management and exams.