A 55-year-old man presents with 8 months of progressive asymmetric resting tremor, rigidity, and bradykinesia. He also reports vivid dreams with acting out behaviors, frequent falls due to postural instability early in the course, and significant orthostatic hypotension. DaTscan shows reduced bilateral striatal uptake. Which is the most likely diagnosis?
- A Idiopathic Parkinson's disease
- B Multiple system atrophy, parkinsonian type (MSA-P) ✓
- C Dementia with Lewy bodies
- D Progressive supranuclear palsy
Correct answer: B. Multiple system atrophy, parkinsonian type (MSA-P)
Explanation
Multiple system atrophy-parkinsonian type (MSA-P) is characterized by parkinsonism plus early autonomic failure (orthostatic hypotension), early postural instability, and REM sleep behavior disorder. Poor response to levodopa is typical. Idiopathic PD rarely has significant autonomic failure or falls early in the course. DLB would have dementia as a prominent feature. PSP would show vertical gaze palsy and early axial rigidity with falls but less prominent autonomic dysfunction. MSA-P fits the full picture best.
Reference: Bradley's Neurology in Clinical Practice, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.