Increased risk of median nerve dysfunction in floor cleaners: A controlledclinical and neurophysiological study

We studied median nerve involvement in a group of asymptomatic handworkers at risk for carpal tunnel syndrome, and we evaluated damage to thin and thi ck nerve fibres in the distribution area of the median nerve. Considering f loor cleaners as workers at high risk of developing cumulative traumatic di sorders in the wrist, we included 42 cleaners and 41 controls. We assessed nerve conduction studies, vibration threshold, and temperature and pain thr esholds of the median nerve. The cleaners had significantly impaired motor nerve conduction velocity (p = 0.006), longer sensory distal. latency (p = 0.01), lower sensory amplitude (p = 0.0005), and increased difference in he at and cold threshold of the median nerve (p = 0.0002). Increased temperatu re threshold was associated with prolonged sensory distal latency of the me dian nerve in the cleaners. In conclusion, impaired neurophysiological vari ables in the median nerve in floor cleaners compared with controls confirm the hypothesis that those workers are at risk of developing median nerve dy sfunction. Sensory nerves seem to be more susceptible to injury than motor branches.