ABSTRACT
Objective To investigate the role of electromyography(EMG) in diagnosis of nervous system diseases in children.(Met)-hods EMG tests were carried out in 354 patients with nervous system diseases,and the data and results of EMG tests were analyzed.Results One hundred and sixty-six patients′ results of EMG were abnormal.Among these abnormalities,36 cases were myogenic,47 cases were neurogenic,abnormalities of 69 cases were located in peripheral nerves,3 cases got positive in repetitive nerve stimulation(RNS),and 11 cases were on the borderline.In 36 myogenic patients,clinical diagnosis were as follow: progressive muscular dystrophy(PMD,18 cases),polymyositis(2 cases),mitochondrial encephalomyopathy(1 case), and the other 15 cases had no definite diagnosis.In 47 neurogenic patients,the diagnosis were spinal muscular atrophy(SMA,29 cases),sequela of poliomyelitis(2 cases),acute transverse myelitis(ATM,4 cases),and the other 12 patients had no definite diagnosis.In 69 cases of peripheral nerve abnormality,diagnosis were injury of brachial nerve(23 cases),hereditary motor sensory neuropathy(HMSN,2 cases),Guillain-Barre syndrome(GBS,9(ca)-ses),chronic inflammatory demyelinating polyradiculoneuropathy(CIDP,1 case),injury of facial nerve(4 cases),injury of common(pe)-roneal nerve(6 cases),metachromatic leukodystrophy(MLD,1 case),and the other 23 patients had no definite diagnosis.Three patients who got RNS positive were all diagnosed myasthenia gravis(MG),and ocular type(1 case),general type(2 cases).Eleven patients whose EMG results were borderline were all diagnosed indefinitely.One hundred and eighty-eight patients had normal results of EMG test.The diagnosis of these patients were included ocular MG(21 cases),cerebral palsy(CP,5 cases),ATM(2 cases),polymyositis((1 case)),and some other nervous system diseases(21 cases),and the other 138 were diagnosed indefinitely.Conclusions 1.EMG plays an important role in definite diagnosis of PMD,SMA,poliomyelitis and nerve injury;2.EMG can provide clue or basis in the differential(dia)gnosis of nervous system diseases which involved lower motor unit;3.EMG test has very low positive results in children with MG;(4.EMG) has little help in diagnosis of diseases involved upper motor unit only.