Electromyography (EMG), nerve conduction studies (NCS), and evoked potentials, including somatosensory- evoked potentials (SSEPs)
and motor-evoked potentials (MEPs), provide useful information to assist the clinician in the localization of pathology within the lower motor neuron and selected areas of the central nervous system.
In the case of acquired or hereditary disorders of the lower motor neuron—anterior horn cell, peripheral nerve, neuromuscular junction (presynaptic or postsynaptic region), or muscle—electrodiagnostic studies are a useful tool as an extension of the clinician's physical examination. The information gained from electrodiagnostic studies may be invaluable in planning subsequent, more invasive diagnostic studies (eg, muscle and nerve biopsy, cerebrospinal fluid [CSF] examination, [magnetic resonance] MR imaging, which at times requires general anesthesia), allow for more cost-effective and specific molecular genetic testing, or aid in the surgical management of peripheral nerve trauma, compressive lesions, or entrapments. In the case of immune-mediated disorders such as myasthenia gravis or Guillain-Barre syndrome, electrodiagnostic studies may permit prompt treatment.Pediatric electrodiagnosis must be approached with knowledge of peripheral neuromuscular development and thoughtful planning of the study with regard to most likely diagnostic possibilities, developmental status of the child, and the likelihood that the pediatric electrodiagnostic practitioner will be able to provide clinicians and family with useful diagnostic information. The physical examination and developmental level of the infant or child directs the study. The examination requires the patience and technical competence of an electrodiagnostic clinician experienced and skilled in the evaluation of children. This chapter will focus on considerations specific to the electrodiagnostic evaluation of infants and children, with an emphasis on practical suggestions that may facilitate the completion of an accurate pediatric electrodiagnostic examination with a minimum of discomfort and distress to the child, parent, and pediatric electrodiagnostic specialist.