Electrophysiological diagnostics in chiari malformation

Abstract

Up to 60% of patients with Chiari type 1 malformation harbor a cervical syringomyelia and a centromedullary syndrome with dissociated pain and thermal sensory impairment, followed by segmental weakness, atrophy, upper motor neuron syndrome, and autonomic dysfunctions due to distension of descending pathways. Comprehensive electrophysiological diagnostics with somatosensory evoked potentials (SSEPs), motor evoked potentials (MEPs), and silent periods help distinguishing between incidental hydromyelia and developing syringomyelia and can provide quantitative parameters for surgical indication in Chiari malformation. Intraoperative neurophysiological monitoring (IOM) can prevent neurological deterioration during positioning and due to microsurgical manipulation for surgeons or institutions with less experience in treating this pathology, in complex or re-exploration cases with scarred medullary junctions or cranio-cervical junction instabilities, and determine the extent of suboccipital decompression.