Neurophysiological diagnosis of hereditary neuropathy with liability to pressure palsies

Objective To explore the neurophysiological properties of hereditary neuropathy with liability to pressure palsies(HNPP),so as to provide evidence for the diagnosis of HNPP.Methods Three families(8 individuals) with clinically affected and asymptomatic HNPP patients underwent routine electrodiagnostic tests,including median,ulnar,radial,tibial and proneal motor and sensory nerve conduction,and the results were compared with those of 30 healthy subjects.Results(1)Prolongation of the distal nerve conduction latencies was the most seen abnormality(92.1%),mainly found in the median and common peroneal nerves,including those with and without symptoms.(2)The rate of motor nerve conduction slowing was 63.2%,mostly seen in the median and common peroneal nerves.(3)The rate of sensory nerve conduction slowing was 89.6%,mostly affecting the sural and median nerves.(4)The conduction block of the ulnar nerve at the elbow was more commonly seen than that of the proneal nerve at the fibular head.Conclusion Neurophysiological examination is a noninvasive,fast,simple and accurate diagnosis way for clinically suspected HNPP patients,and it can be used for screening the family members of HNPP patients and for prevention of HNPP.