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

Abstract

Study design: 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. Objectives: The objective of our study was to evaluate motor pathways in children with viral myelitis using the TMS technique. Setting: All investigations were performed in Scientific Research Institute for Children's Infections, Russia. Results: 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. Conclusion: 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. Spinal Cord (2016) 54, 226-228; doi:10.1038/sc.2015.129; published online 4 August 2015 INTRODUCTIONAcute transverse myelitis is the infrequent, severe and potentially devastating condition that has been estimated to occur with an annual worldwide incidence of 4 cases per 100 000 individuals. 1 In pediatric population, it often results in motor, sensory and autonomic dysfunction, with growing demand for reliable diagnostic and prognostic tools. 2 Clinical examination in children is sometimes unreliable, and standard neurophysiologic tests could be insufficient in setting precise diagnosis; thus, transcranial magnetic stimulation (TMS) is considered as one of the valuable diagnostic methods. 3,4 TMS is a method for focal noninvasive brain stimulation that is based on the principles of electromagnetic induction. 5 TMS is an effective diagnostic and a therapeutic technique with applications in neurology, psychiatry and rehabilitation medicine, which can provide insight into developmental neurology and neurophysiology in children. 6 TMS can detect corticospinal tract abnormalities not identified by neuroimaging. 3,4,6 In the patients with compressive myelopathies, TMS was found to be helpful in determining the functional significance of neuroimaging findings. TMS can supplement clinical examination and neuroimaging findings also in the assessment of the spinal cord injury level. 3,4 However, reports of TMS use in pediatric acute myelitis are relatively rare, and mostly such works are case reports or small series consisting of 2-3 patients. 7 We have performed the investigation of corticospinal pathway characteristics in children with acute myelitis, with special attention toward clinical significance of TMS and its prognostic value in this case.

Relationship Between Motor Evoked Potential Response and the Severity of Paralysis in Spinal Cord Injury Patients

“…Previous studies have suggested the usefulness of MEP as a screening and diagnostic tool for myelopathy, and as a prognostic predictor after spinal cord injury (SCI) [78910]. Nakamae et al [7] reported that MEP latency and central motor conduction time (CMCT) were prolonged (86% and 59%, respectively) among myelopathy patients and a control group.…”

“…Nakamae et al [7] reported that MEP latency and central motor conduction time (CMCT) were prolonged (86% and 59%, respectively) among myelopathy patients and a control group. In patients with acute transverse myelitis CMCT, where MEP amplitudes were different from a control, MEP shapes were abnormal (96% of patients), and MEP thresholds were elevated [8]. Meanwhile, Curt et al [9] analyzed the significance of MEP latency and amplitude in predicting motor function in acute and chronic SCI patients.…”

The role of the neurophysiological methods in the assessment of the effectiveness of the rehabilitation of sensorimotor disturbances associated with the lesions of the central nervous system at the spinal cord level

“…Следует отметить, что в ранее проводившихся исследованиях у взрослых пациентов с неполным травматическим поражением спинного мозга неблагоприятным признаком, с точки зрения восстановления движения, являлось отсутствие ВМО при ТМС ниже места поражения [12]. Сходные закономерности были отмечены нами при применении диагностической ТМС в качестве инструмента прогнозирования и у детей с последствиями ОВМ [13]. Сочетанное использование диагностической ТМС и ССВП рекомендуется при широком спектре спинальной патологии, в частности при лечении спондилогенной шейной миелопатии методом ламинопластики [14], для объективной оценки состояния проводящих путей на центральном уровне, при обследовании пациентов с тяжелой сколиотической деформацией позвоночника [15].…”

Transcranial magnetic stimulation as an additional diagnostic tool in children with acute inflammatory demyelinating polyneuropathy

“…[ 4 5 ] In children with inflammatory lesions of the nervous system, for example, acute transverse myelitis, TMS may serve as a diagnostic and prognostic tool. [ 6 ]…”