Small fiber neuropathy in Charcot-Marie-Tooth disease.

UNLABELLED The aim of this study was to investigate small myelinated (Adelta) and unmyelinated (C) fiber function in patients with CMT1A and CMTX polyneuropathy. 17 CMT1A and 10 Cx32 polyneuropathy patients were investigated with warm and cold threshold to evaluate small myelinated (Adelta) an unmyelinated (C) somatic fiber function and with sympathetic skin responses (SSR) to evaluate postganglionic sympathetic fiber function. Median age and disease duration did not differ between the two groups. Charcot-Marie-Tooth neuropathy score was higher in CMTX patients. Mean MCV differed significantly between the two groups in both Median and Ulnar nerve. In CMT1A patients warm threshold was abnormal in 72% and cold threshold in 53%. On the contrary, in Cx32 patients group warm and cold threshold was abnormal in 10 and 20% respectively. SSR was also abnormal in only a small number of both CMT1A and Cx32 patients (24% and 10% respectively). CONCLUSION Small fiber function is frequently impaired in CMT1A polyneuropathy patients.