Motor evoked potentials and compound muscle action potentials as prognostic tools for neonates with spina bifida

MEPs and CMAPs as prognostic tools for spina bifida. Aim: The aim of this prospective study was to determine the prognostic value of neurophysiological investigations compared to clinical neurological examination in infants with spina bifida. Methods: Thirty-six neonates born with spina bifida between 2002 and 2007 were evaluated and followed for 2 years. Lumbar motor evoked potentials (MEPs) and compound muscle action potentials (CMAPs) were obtained at the median age of 2 days old before surgical closure of the spinal anomaly. MEPs were recorded from the quadriceps femoris, tibialis anterior, and gastrocnemius muscles and CMAPs from the latter two muscles. Areas under the curve and latencies of the MEPs and CMAPs were measured. Clinical neurological outcome at the age of 2 years was described using Muscle Function Classes (MFCs) and ambulation status. Results: The areas under the curve of MEPs and CMAPs in the legs were associated with lower neonatal levels of motor and sensory impairment. Better muscle function class of the lower limbs at 2 years of age was associated with larger MEP and CMAP areas of the gastrocnemius and tibialis anterior muscles at neonatal age. Discussion: MEPs and CMAPs of the gastrocnemius and tibialis anterior muscles are of prognostic value for clinical neurological outcome in neonates born with spina bifida.