Electromyographic Findings in Overt Hypothyroidism and Subclinical Hypothyroidism

Abstract

OBJECTIVE: Hypothyroidism may cause neurologic signs and symptoms as its effects neuromuscular system like many other systems. Subclinical hypothyroidism is the most common thyroid dysfuntion, it may cause neuromuscular signs and symptoms. In this retrospective study, it is aimed to compare neuromuscular symptoms and electromyographic (EMG) manifestations between hypothyroid patients and control group with normal thyroid function and without a disease causing polyneuropathy. METHODS: 31 overt hypothyroidic, 139 subclinic hypothyroidic patients and 50 individuals with normal thyroid function, without a disease causing polyneuropathy, as control group whom made EMG for another reason were included to the study. Neuromuscular symptoms, neurological examination and electrophysiological findings was obtained from the patient records. RESULTS: In our study, we observed frequent neuromuscular complaints such as fatigue, morning stiffness, cramp, general pain and paresthesia in favor of both for overt and subclinic hypothyroidism. Carpal Tunnel Syndrom(CTS), was statistically higher in overt hypothyroidism group than control group. CTS was also observed higher in subclinic hypothyroidism group when compared with control group but it didn't reach to statistical significance. We did not detect polyneuropathy in any group. Motor nerve velocity and compound muscle action potential amplitudes were found to be statistically significant difference between hypothyroid ve control group. CONCLUSION: Since motor fibres' and neuromuscular area's being affected in hypothyroidism, which we interpret to happen due to basal metabolism's slowing down, can show a significant recovery after thyroid replacement therapy. We consider that, in further studies, comparison of electrophysiological findings after treatment with the findings of pre -treatment is necessary

Keywords

• Hypothyroidism
• neurologic signs and symptoms
• electromyography