Electrically evoked multiplet discharges are associated with more marked clinical deterioration in motor neuron disease.

INTRODUCTION

The aim of this study was to determine whether electrically evoked multiplet discharges (MDs) are related to severity of clinical deterioration in motor neuron disease (MND).

METHODS

Stimulated high-density surface electromyographic (HDsEMG) recordings were performed in thenar muscles. Data were collected from 31 MND patients. MDs from the HDsEMG recordings were determined at baseline. ALSFRS-R scores were obtained at baseline and at a maximum of 16 weeks follow-up.

RESULTS

The presence of MDs was associated with progressive deterioration of ALSFRS-R score (P = 0.02) and fine motor function (FMF) (P < 0.001). Patients who had a higher number of motor units that generated MDs (r = 0.61, P < 0.001) and patients who had a higher number of MDs (as percentage of applied stimuli) (r = 0.59, P = 0.001) had a more severe decline in FMF.

CONCLUSIONS

Electrically evoked MDs are associated with more marked clinical deterioration in patients with MND.