Clinical Reasoning: A 58-Year-Old Man With Resting Tremor, Bradykinesia, and Distal Numbness

A 58-year-old man presented with progressive right-hand loss of dexterity and resting tremor over 2 years, accompanied by sensory symptoms in the distal extremities and chronic cough. Neurologic examination revealed asymmetric parkinsonism, distal hypoesthesia, and decreased vibratory sensation. Nerve conduction studies revealed a non-length-dependent axonal polyneuropathy. This case presents a structured approach to both parkinsonism and polyneuropathy, and the clinical reasoning necessary when dealing with multiple system involvement, in which different differential diagnoses should be considered.