Use of stimulated electromyography in the analysis of the neuromuscular junction in children.

A screening test is required to diagnose disorders of the neuromuscular junction (NMJ) in children. This Review describes the development of stimulation potential analysis with concentric needle electrodes (SPACE). This nomenclature was chosen to distinguish the technique from single-fiber methodology because of the difficulties in identifying single-fiber potentials in most studies, particularly those with the most severe abnormalities of the NMJ. Performed on orbicularis oculi in children with proven or probable disorders of the NMJ, it demonstrated a sensitivity of 84%, specificity of 71%, negative predictive value of 95%, and positive predictive value of 36%. It is well tolerated and within the capability of any clinical neurophysiologist. When combined with a full electrodiagnostic examination, SPACE provides invaluable information about children with NMJ disorders, whose diagnosis often is difficult. Muscle Nerve 56: 841-847, 2017.