Asymptomatic median mononeuropathy among men with chronic paraplegia.

OBJECTIVES

To compare electrophysiologic abnormalities of the median nerve in asymptomatic paraplegic subjects and able-bodied controls and to examine the influence of personal factors on these parameters.

DESIGN

Cross-sectional survey.

SETTING

University hospital.

PARTICIPANTS

Forty-seven men with paraplegia and 36 able-bodied controls underwent nerve conduction studies on both upper limbs. All were free of hand numbness in the past month, diabetic mellitus, or neuromusculoskeletal injuries to the upper limbs.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Nerve conduction studies of the bilateral median and ulnar nerves.

RESULTS

Although the 2 groups were of comparable age and had a similar body mass index (BMI), the subjects with paraplegia had a significantly higher proportion of asymptomatic median mononeuropathy than the controls (25.5% vs 5.6%, P=.02). The spinal cord injury (SCI) group had a prolonged median distal latency and a slowed digit-wrist sensory nerve conduction velocity. Multivariate general linear model analysis showed that prolonged motor and sensory latencies of the median nerve were associated with the SCI group and with greater BMI.

CONCLUSIONS

The asymptomatic subjects with paraplegia had a significantly higher frequency of median mononeuropathy than the able-bodied controls. There was also an association between BMI and distal latency of the median nerve.