Clinical Manifestations and Electrophysiology Analysis of Spinal Muscular Atrophy in Children / 实用儿科临床杂志

ABSTRACT

Objective To explore the features of clinical manifestations and electrophysiology of spinal muscular atrophy(SMA) in children.Methods The clinical features and laboratory data were analyzed in 32 children with SMA,electromyography tests were carried out in 28 patients and the muscle biopsy were performed in 24 cases.Results The 32 cases were subdivided into 3 clinical groups,15 cases were SMAⅠ,12 cases were SMAⅡ,5 cases were SMAⅢ.They were all characterized by progressive muscle weakness associated with hyptonia and atrophy.The clinical distinction between SMAⅠto SMAⅢ reflected different age of onset and disease severity.All cases of SMAⅠhad symptoms of respiratory disability,only 1 case of SMAⅡ had paradoxical breathing and none of SMAⅢ had similarly symptoms.Electromyographic studies showed a pattern of denervation with no sensory involvement.The rate of spontaneous potential was 87%,with gentle strain,the duration of motor unit was extended(30%-150%) and the amplitude of it was increased(90%-450%),the motor nerve conduction velocity was reduced slightly in 28% patients.The muscle biopsy provided evidence of skeletal muscle denervation with groups of atrophy.Conclusions The clinical features,the changes of electromyography and the muscle biopsy are valuable for diagnosis of SMA.Respiratory management will prolong survival and improve the quality of life for these patients.