Directionality analysis of transcallosal communication utilizing the ipsilateral silent period in people with multiple sclerosis

Voiceover

Presenter(s)

Sydney Petersen

Abstract or Description

Multiple sclerosis is a neurodegenerative disease characterized by damage to the central nervous system (CNS). The CNS includes structures such as the corpus callosum: the largest white matter tract connecting the cerebral hemispheres. In persons with multiple sclerosis (PwMS), degradation of the corpus callosum can result in asymmetric gait due to the lack of coordination of bilateral movement. The ipsilateral silent period (iSP) is a measure of interhemispheric inhibition. iSP metrics were utilized to relate differences in directionality from the two cerebral hemispheres, as most PwMS have hemispheres that are more and less affected by the disease. Twenty-nine participants completed the study and iSP metrics of duration, average depth, and maximum depth were analyzed for interhemispheric inhibition. Muscle activity of the first dorsal interosseus muscle was monitored while single pulse transcranial magnetic stimulation (TMS) was delivered to the ipsilateral primary motor cortex. We hypothesized that reduced transcallosal inhibition may be an underlying neuropathological mechanism driving gait asymmetry in PwMS due to directionality differences between more and less affected hemispheres. While there were no significant differences in the directionality of iSP metrics from the less to more affected hemispheres, these findings suggest interhemispheric inhibition may be preserved in people with MS, and other factors may be driving gait asymmetry. More investigation regarding underlying neural mechanisms is necessary, and research investigating the neurophysiology and gait metrics are pivotal to individualize potential rehabilitation protocol for people with MS.

Mentor

Dr. Brett Fling, PhD