Diagnostic transcranial magnetic stimulation as a prognostic tool in children with acute transverse myelitis

We performed transcranial magnetic stimulation (TMS) in children with sequelae of acute transverse myelitis. Single-pulse TMS protocol was implemented. Twenty controls and 24 patients with myelitis were enrolled. TMS was performed on 12-24 day after the onset of the first symptoms, average on 16th day.

The objective of our study was to evaluate motor pathways in children with viral myelitis using the TMS technique.

All investigations were performed in Scientific Research Institute for Children's Infections, Russia.

There were statistically significant differences between the groups on central motor conduction time and motor evoked potential (MEPs) amplitudes. MEP thresholds were elevated, and MEP shape was abnormal in 96% of patients with myelitis (n=23). Three neurophysiologic patterns were observed: the presence of both cortical and spinal MEP, the absence of cortical MEP with the spinal MEP present and the total absence of both cortical and spinal MEP. Last finding was associated with paraplegia, resistant to any sort of treatment.

Thus, myelitis in 96% of the cases causes neurophysiologic changes, which may be detected by TMS; the method may be used as a predicting tool.