Prediction of Motor Recovery Using Quantitative Parameters of Motor Evoked Potential in Patients With Stroke

Abstract

ObjectiveTo investigate the clinical significance of quantitative parameters in transcranial magnetic stimulation (TMS)-induced motor evoked potentials (MEP) which can be adopted to predict functional recovery of the upper limb in stroke patients in the early subacute phase.MethodsOne hundred thirteen patients (61 men, 52 women; mean age 57.8±12.2 years) who suffered faiarst-ever stroke were included in this study. All participants underwent TMS-induced MEP session to assess the corticospinal excitability of both hand motor cortices within 3 weeks after stroke onset. After the resting motor threshold (rMT) was assessed, five sweeps of MEP were performed, and the mean amplitude of the MEP was measured. Latency of MEP, volume of the MEP output curve, recruitment ratios, and intracortical inhibition and facilitation were also measured. Motor function was assessed using the Fugl-Meyer Assessment scale (FMA) within 3 weeks and at 3 months after stroke onset. Correlation analysis was performed between TMS-induced MEP derived measures and FMA scores.ResultsIn the MEP response group, rMT and rMT ratio measures within 3 weeks after stroke onset showed a significant negative correlation with the total and upper limb FMA scores at 3 months after stroke (p<0.001). Multiple regression analysis revealed that FMA score and rMT ratio, but not rMT within 3 weeks were independent prognostic factors for FMA scores at 3 months after stroke.ConclusionThese results indicated that the quantitative parameter of TMS-induced MEP, especially rMT ratio in the early subacute phase, could be used as a parameter to predict motor function in patients with stroke.

Mylohyoid motor evoked potentials can effectively predict persistent dysphagia 3 months poststroke

“…Our results regarding rMT can be indirectly compared with the results of previous studies on motor recovery after stroke. Jo et al . showed that the rMT ratio can predict motor function 3 months after stroke.…”

“…Latency and amplitude stimulation at 120% (amp120) and 150% (amp150) of the rMT value in both hemispheres were also assessed. For each stimulation intensity, five sweeps of the MEP were collected, and the average of each maximal amplitude was adopted . The latency was measured only in the trial with the shortest onset latency .…”

“…The latency was measured only in the trial with the shortest onset latency . The ratios of the rMT, amp120, amp150 and latency were estimated by dividing the value of the affected hemisphere by the value of the unaffected hemisphere and multiplying by 100 …”

“…For each stimulation intensity, five sweeps of the MEP were collected, and the average of each maximal amplitude was adopted. 28,29 The latency was measured only in the trial with the shortest onset latency. 14 The ratios of the rMT, amp120, amp150 and latency were estimated by dividing the value of the affected hemisphere by the value of the unaffected hemisphere and multiplying by 100.…”

“…14 The ratios of the rMT, amp120, amp150 and latency were estimated by dividing the value of the affected hemisphere by the value of the unaffected hemisphere and multiplying by 100. 29,30…”