Neurophysiological testing in congenital myasthenic syndromes: A systematic review of published normal data

Introduction: Congenital myasthenic syndromes are a heterogeneous group of inherited neuromuscular disorders. Neurophysiological testing has a major role in screening suspected cases and guiding genetic testing. We performed a systematic literature review to ascertain whether sufficient age-specific normative data exist for these techniques. Methods: We searched Ovid Medline (1948 to October 2012) for citations on repetitive nerve stimulation (RNS) or single fiber electromyography (SFEMG) in children. Results: We identified 5 articles containing data on 48 normal children studied with RNS and 1 article containing data on SFEMG in 20 normal children. A variety of techniques were used, including a variety of stimulation frequencies. Nevertheless, the data identify significant differences in the response to RNS in children as compared with adults, emphasizing the need for adequate age-appropriate normal values. Conclusions: We found a paucity of published normal data for pediatric neuromuscular transmission studies. Further studies using standardized techniques are needed to expand the currently limited pool of available data. 

Muscle Nerve November 2013