A 60-year-old man presents with resting tremor, rigidity, bradykinesia, and postural instability over 3 years. His symptoms are predominantly asymmetric. He has poor response to high-dose levodopa. Which feature best distinguishes atypical parkinsonian syndrome (Parkinson plus) from idiopathic Parkinson disease?

• A Early falls and poor levodopa response ✓
• B Resting tremor
• C Asymmetric onset of motor symptoms
• D Olfactory dysfunction

Explanation

Early falls (within first year) and poor or absent response to levodopa strongly suggest an atypical parkinsonian syndrome such as progressive supranuclear palsy (PSP) or multiple system atrophy (MSA) rather than idiopathic PD. Idiopathic PD typically shows excellent levodopa response (hallmark feature), asymmetric onset, and resting tremor. Olfactory dysfunction (hyposmia) is characteristic of idiopathic PD and is absent in most Parkinson-plus syndromes. Symmetric onset also raises suspicion for atypical syndromes.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.