Clinical Reasoning: A 55-Year-Old Man With Rapidly Progressive Weakness and Numbness.

A 55-year-old man with uncontrolled diabetes presented with progressive length-dependent weakness, numbness, and paresthesia, leading to profound upper extremity weakness and lower extremity paraplegia in 4 months. A review of systems additionally revealed leg edema, chest wall erythema, and weight loss. Nerve conduction study/electromyography (NCS/EMG) showed axonal length-dependent sensorimotor polyneuropathy. Additional testing revealed a rare etiology. Treatment was started, and the patient's symptoms stabilized. This report discusses the diagnostic approach to rapidly progressive polyneuropathies, emphasizing careful systemic examination, laboratory studies, imaging, and electrophysiologic testing. It also highlights the importance of looking beyond neurologic signs to identify systemic evidence of disease involvement.