Retrospective case series of peripheral neuropathy following carbon monoxide poisoning: clinical and electrophysiological characteristics

Abstract Background Peripheral neuropathy following carbon monoxide (CO) poisoning is considered a rare complication of CO intoxication. The following study analyzes the clinical features and electromyography (EMG) findings of patients with limb weakness after CO poisoning. Methods A retrospective analysis was conducted on 13 patients from the Second Hospital of Lanzhou University database, diagnosed between January 2016 and November 2025. These patients presented with acute CO poisoning, concurrent limb weakness, and electrophysiologically confirmed peripheral neuropathy. Results The mean age of the 13 patients with peripheral neuropathy after CO poisoning was 35.2 years (SD: 20.7, range 5–70). The severity of muscle weakness ranged from mild to complete paralysis. Electrophysiological testing revealed pure upper limb neuropathy (5/13), pure lower limb neuropathy (7/13), and combined upper and lower limb neuropathy (1/13). Among these cases, mononeuropathy was observed in 4/13, multiple mononeuropathy in 5/13, plexopathy in 3/13, and combined plexopathy with mononeuropathy in 1/13. Four patients exhibited pure motor nerve involvement, while one patient with multiple mononeuropathy showed pure motor nerve involvement in one affected nerve and combined sensorimotor nerve involvement in another. The remaining patients all demonstrated combined sensorimotor nerve involvement. Only two cases presented with combined myelin and axonal damage, while the others showed axonal damage. Conclusions The significant limb weakness following CO poisoning is associated with peripheral neuropathy, which may manifest as mononeuropathy, multiple mononeuropathy, or plexopathy, primarily characterized by axonal damage.