Chapter 36 Neurophysiological markers of recovery of function after stroke

Publisher Summary The progressive balancing of the hemispheric output during voluntary contraction turned out to be one of the neurophysiological markers of good clinical recovery. It clearly emerged that interhemispheric differences of the examined items yield significantly more abnormalities than their absolute values. Therefore, the analysis of interhemispheric asymmetries of the neurophysiological parameters beside their absolute values could significantly enlarge the diagnostic-prognostic yield. A follow-up of the neurophysiological markers of corticospinal tracts and functionality related to motor performances and skills in daily living activities has been performed. In addition, transcranial magnetic stimulation (TMS) performed in subacute stroke patients and during follow-up can provide some insights into the understanding of the mechanisms involved in the recovery of motor function, following the stroke. In the TMS mapping study, clinical recovery has been found to be related to the improvement of several motor evoked potentials (MEPs) measures, including the enlargement of the motor cortical output area to the paretic muscles, the increased MEP amplitude, the shortened MEP latency, central conduction time (CCT), and the decreased silent period (SP) duration. Interhemispheric asymmetries of MEPs might represent a powerful neurophysiological indicator of motor dysfunction and could be proposed as more useful for a diagnostic/prognostic tool.