Compressive mononeuropathies of the upper extremity in chronic paraplegia

Abstract

Controversy exists with regard to the actual prevalence of compressive mononeuropathies at the wrist which may occur following chronic paraplegia. Thirty one chronic paraplegics, with a mean age of 37.9 years (range 20-68 years), and mean time since injury of 9.7 years (range 1-28 years), were studied with a comprehensive neurologic and electrodiagnostic (EDX) assessment. No patient had any clinical or EDX evidence of a peripheral polyneuropathy. The diagnosis of a median mononeuropathy at the wrist was determined by the following criteria: (a) prolonged median sensory distal latency greater than ipsilateral ulnar sensory distal latency greater than or equal to 0.5 msec; (b) a median mid-palmar sensory latency greater than ipsilateral ulnar mid-palmar sensory latency of greater than or equal to 0.3 msec; or (c) a median motor distal latency greater than or equal to 1.7 milliseconds as compared to the ipsilateral ulnar motor distal latency. Ulnar mononeuropathy at the wrist or across the elbow was also characterised. The EDX criteria for a median mononeuropathy at the wrist was met in 55% of subjects (24% of these with bilateral presentations). The location of ulnar mononeuropathies included: two at the superficial sensory branch at the wrist, one at the deep motor branch at the wrist, and three patients with a conduction block across the elbow. Overall, 67% of all patients tested had evidence of at least one mononeuropathy of the upper extremity. There was no association between prevalence of compressive mononeuropathies and age of the patient or time since onset of injury.