A 70-year-old man has progressive memory loss, apathy, and word-finding difficulty. MRI shows bilateral hippocampal and entorhinal cortex atrophy. PET scan shows hypometabolism in the posterior temporoparietal regions. CSF shows reduced Abeta-42 and elevated p-tau. These findings are MOST consistent with:
- A Alzheimer's disease (AD) ✓
- B Frontotemporal dementia (FTD)
- C Vascular dementia
- D Normal pressure hydrocephalus
Correct answer: A. Alzheimer's disease (AD)
Explanation
The combination of episodic memory impairment + hippocampal/entorhinal atrophy on MRI + posterior temporoparietal hypometabolism on FDG-PET + CSF biomarkers (reduced Abeta-42 reflecting amyloid plaque deposition, elevated phospho-tau reflecting neurofibrillary tangles) is the biomarker signature of Alzheimer's disease. FTD shows frontal-temporal atrophy and hypometabolism with predominant behavioral/language symptoms. Vascular dementia has stepwise decline and white matter changes.
Reference: Kaplan & Sadock's Synopsis of Psychiatry, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.