Is there a correlation between sensory and motor axonal damage of the median nerve during carpal tunnel syndrome?

Abstract

Objectives Carpal tunnel syndrome (CTS) is the most common nerve compression. The Electroneuromyography (ENMG) is the most objective test to document neurophysiological abnormalities [1] . Sensory impairment often precedes motor impairment, and demyelination precedes axonal loss. To our knowledge, no study has investigated the relationship between sensory and motor impairment. The aim of this work is to look for a correlation between sensory axonal loss and motor loss of the median nerve. Methods This is a retrospective study that regrouped 60 patients (120 hands) and for whom the diagnosis of CTS was retained following the ENMG. The statistical study was carried out with SPSS 20 software. The correlation was studied by the Pearson test. Results The mean age of the patients was 53.16 ± 11.8 years. The female sex was predominant with a sex ratio of 0.11. Diabetes was present in 40% of patients and hypothyroidism in one patient. The clinical lesion was bilateral in 75% of cases. Tinel sign was positive in 59.2% of the hands and phalen sign in 53.3% of the hands. The ENMG objectified CTS in 89.2% of hands with sensory-motor involvement in 50.8% of hands. Axonal loss was found in 36.7% of the hands. Mean sensory and motor amplitude was 63.4 ± 46.7 uV and 12.54 ± 4.9 mV respectively. The Pearson test showed a significant correlation between the amplitude of the sensory potential and that of the motor potential of the median nerve (P = 0.005). Conclusion This study shows a correlation between sensory and motor axonal loss. A multicenter study is needed to better retain this correlation relationship.