Background: Although contradictory results regarding neuromuscular functions have been reported in adults with subclinical hypothyroidism (SH), there is no study evaluating neuromuscular functions in children with SH.
Objective and hypotheses: To assess neuromuscular functions using nerve conduction studies in children with SH.
Method: Twenty-six children (518 years) with SH were enrolled in the study. Neuromuscular functions were examined by electroneuromyography (ENMG). Sensory and motor nerve conduction studies were performed in the left upper and lower limbs. Of the motor nerves, the median, ulnar, peroneal, and tibial nerves and of the sensory nerves, the median, ulnar, and sural nerves were examined. Combined muscle action potential in the motor nerves, amplitudes in the sensory nerves and distal latency and nerve transmission rates in the motor and sensory nerves were assessed. Results were compared with normal values according to age.
Results: In six patients, the etiology was autoimmune thyroid disease. In ENMG, motor axonal involvement was observed in 10 patients (peroneal involvement in five patients (19.2%), tibial involvement in two patients (7.6%), ulnar involvement in two patients (7.6%), and median involvement in one patient), while no sensory axonal involvement was observed in any of the patients. While two patients with motor axonal involvement were symptomatic, other cases were asymptomatic. In one of the symptomatic patients, motor axonal involvement in three regions (ulnar, peroneal, and tibial) was observed. Nerve conduction values were normal in all patients.
Conclusion: Our study findings suggest that subclinical or clinical axonal involvement may be present in children with SH. We believe that these findings may offer an insight in the treatment of SH, which still remains controversial, in this patient population.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology