Muscle responses to radicular stimulation during lumbo-sacral dorsal rhizotomy for spastic diplegia: Insights to myotome innervation. Issue 5 (May 2020)

• Record Type: Journal Article
• Authors: Georgoulis, George; Sindou, Marc
• Is Part Of: Clinical neurophysiology. Volume 131:Issue 5(2020:May)
• Page Start: 1075
• Page End: 1086
• Publication Date: 2020-05
• Subjects: Spinal nerve root -- Motor root innervation -- Myotomes -- Intraoperative neuromonitoring -- Dorsal rhizotomy -- Functional anatomy; CMAP Compound Motor Action Potentials -- CP Cerebral Palsy -- DR Dorsal Root -- D.Rh. Dorsal Rhizotomy -- EMG Electromyography -- GMFM Gross Motor Function Measure -- IL Interlaminar -- KIDr Keyhole Interlaminar Dorsal rhizotomy -- VR Ventral Root; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2020.02.007
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: Study shows important inter-individual variability in myotome innervation among patients. Most muscles have multi-radicular innervation. Root territories strongly overlap, not only under dorsal but also ventral stimulation at threshold. Abstract: Objective: Most of knowledge on muscle radicular innervation was from explorations in root/spinal cord pathologies. Direct and individual access to each of the lumbar-sacral -ventral and dorsal- nerve roots during dorsal rhizotomy for spastic diplegia allows precise study of the corresponding muscle innervation. Authors report the lumbo-sacral segmental myotomal organization obtained from recordings of muscle responses to root stimulation in a 20-children prospective series. Methods: Seven key-muscles in each lower limb and anal sphincter were Electromyography (EMG)-recorded and clinically observed by physiotherapist during L2-to-S2 dorsal rhizotomy. Ventral roots (VR), for topographical mapping, and dorsal roots (DR), for segmental excitability testing, were stimulated, just above threshold for eliciting muscular response. Results: In 70% of the muscles studied, VR innervation was pluri-radicular, from 2-to-4 roots, with 1 or 2 roots being dominant at each level. Overlapping was important. Muscle responses to DR stimulation were 1.75 times more extended compared to VR stimulation. Inter-individual variability was important. Conclusions: Accuracy of root identification and stimulation with the used method brings some more precise information to radicular functional anatomy. Significance: Those neurophysiological findings plead for performing Intra-Operative Neuromonitoring when dealing with surgery in the lumbar-sacral roots.