Electroneuromyography and neuromuscular findings in 16 primary hypothyroidism patients

Abstract

-There has been few reports on electroneuromyography (ENMG) changes in hypothyroidism. The objectives of the present study were to investigate the frequency of ENMG abnormalities in hypothyroidism and correlate them with neurological signs and symptoms and muscle enzyme levels; and to compare latency, amplitude and nerve conduction velocity from selected nerves with controls. Sixteen patients suffering from primary hypothyroidism were submitted to ENMG before treatment. ENMG abnormalities were found in 87.5% of the patients; 46.6% had myopathy and 43.7% had carpal tunnel syndrome. There was no case of polyneuropathy. A clear-cut clinical, laboratorial and ENMG correlation was observed in patients with myopathy and carpal tunnel syndrome. The patients showed a significant tendency of nerve conduction slowness as compared with controls. The findings are in accordance with the well-known nerve and muscle damage in hypothyroidism.KEY WORDS : primary hypothyroidism, electroneuromyography, carpal tunnel syndrome, myopathy. Achados eletroneuromiográficos e neuromusculares em 16 pacientes com hipotireoidismo primárioRESUMO -Foram avaliados através de eletroneuromiografia (ENMG) 16 pacientes com hipotireoidismo primário de diversas etiologias, virgens de tratamento, com o objetivo de: estabelecer a incidência de alterações; correlacioná-las com parâmetros clínicos referentes ao acometimento do sistema nervoso periférico e níveis de enzimas musculares; estabelecer a comparação entre valores médios da latência, amplitude e velocidade de condução nervosa de alguns nervos selecionados no grupo de pacientes e de grupo controle. Alterações da ENMG foram encontradas em 87,5% dos casos, sendo estabelecido diagnóstico eletrofisiológico de miopatia em 46,6% e de síndrome do túnel do carpo em 43,7%. Nenhum dos casos foi identificado como polineuropatia. A concordância entre sintomatologia (100%), exame neurológico (28,57%), níveis de enzimas musculares (42,85%) e ENMG foi elevada para casos de miopatia. Nos casos de síndrome do canal carpiano foi respectivamente de 71,42% para sintomatologia e 71,42% para exame neurológico. A comparação de valores médios dos parâmetros selecionados de neurocondução, entre pacientes e controle, demonstrou tendência generalizada à lentificação da condução nervosa no hipotireoidismo primário. A literatura revista concorda com os dados dos autores em relação à extensão do dano de nervo e músculo nessa endocrinopatia. PALAVRAS-CHAVE: hipotireoidismo primário, eletroneuromiografia, síndrome do túnel do carpo, miopatia.Primary hypothyroidism is a chronic and insidious disease caused by failure of thyroid hormone production mostly due to inflammation, thyroidectomy, use of 1131, and anti-hyperthyroidism drugs. A wide variety of systems may be affected, such as renal, digestive, cardiac, circulatory and nervous. The nervous system may be damaged centrally or peripherally. Dysfunction of the peripheral nerve system (PNS) is not infrequent and should prompt correct diagnosis and treatment of this end...

Pathological Features of Polyneuropathy in Three Dogs

“…Altered Schwann cell metabolism may cause mucinous deposition, which results in nerve entrapment and demyelination [9,15,29]. Severe metabolic defects in neurons may also disturb axonal transport and lead to axonal atrophy [9,15,29].…”

“…Altered Schwann cell metabolism may cause mucinous deposition, which results in nerve entrapment and demyelination [9,15,29]. Severe metabolic defects in neurons may also disturb axonal transport and lead to axonal atrophy [9,15,29]. Vascular nerve damage secondary to hypothyroid-induced alternations in the blood-nerve barrier may also cause demyelination [9,15,29].…”

Evaluation of F-wave study in assessment of neuropathy among hypothyroid patients with or without clinical neuro deficit- A case control study

“…Nerve conduction studies have been used to estimate electrophysiological prevalence of polyneuropathies, entrapment neuropathies and myopathies in hypothyroid patients. 9 EDX studies often revealed neuromuscular slowing in hypothyroids. Latencies prolonged, Conduction velocities reduced had been reported in previous studies.…”

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