The clinical analysis of neuroelectrophysiologic diagnosis in bereditary neuropathy with liability to pressure palsies: four cases of one pedigree / 中国基层医药

Objective To investigate the electrophysiological changes of peripheral nerves in both patients with hereditary neuropathy with liability to pressure palsies(HNPP).Methods The nerve conduction velocities of a family consisting of a proband and 4 members were tested,and the proband was detected by biopsy.Results The proband's median nerve,ulnar nerve,sural sensory nerve conduction velocity (SCV) were decreased.The median nerve,ulnar nerve,common peroneal nerve motor nerve conduction velocity(MCV) of proband were decreased.The sensory fibers of the most frequently involved nerve sural nerve,sural nerve damage to the results:the motor nerve conduction motor nerve evoked potential latency and 18 abnormal rate was 75.0％,the nerve distal to the abnormal rate of MCV was 87.5％.Conclusion Prolongation of distal nerve conduction latencies occurs in essentially all individuals whether symptomatic or asymptomatic.Nerves may be more easily damaged at the site of compression.

Hereditary neuropathy with liability to pressure palsies (HNPP) patients of Korean ancestry with chromosome 17p11.2-p12 deletion

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant inherited disorder characterized by recurrent pressure palsies. Most HNPP patients have a 1.5 mb deletion in chromosome 17p11.2-p12. The present study aimed at evaluating the deletion of the 17p11.2-p12 region in Korean subjects with families exhibiting HNPP phenotype, and to determine the clinical, electrophysiological and morphological aspects specifically associated with this deletion in HNPP patients. By genotyping six microsatellite markers (D17S921, D17S955, D17S1358, D17S839, D17S122 and D17S261), HNPP with the deletion was observed in 79% (19 of 24) of HNPP families. Nerve conduction studies were performed in 35 HNPP patients from these 19 families. The observed HNPP deletion frequency in Koreans is consistent with findings in other populations. Disease onset occurred at a significantly earlier age in patients with recurrent pressure palsies than in those with a single attack (P<0.01). Nerve conduction studies demonstrated diffuse mild to moderate slowing of nerve conduction velocities that were worse over the common entrapment sites, regardless of the clinical manifestations. A long duration of compound muscle action potentials without a conduction block or a temporal dispersion is a characteristic of this disease. A sural nerve biopsy with teasing was performed in four patients, and tomacula of the myelin sheath was found in 56.4%. Our findings appear to support the existence of a phenotype/genotype correlation in HNPP patients of Korean ancestry with the deletion, and suggest that HNPP patients with earlier symptom onset face an increased chance of having recurrent attacks.