Relationship between Contralateral and Ipsilateral Motor Evoked Potentials and Upper Limb Function in Hemiplegic Patients

J Korean Assoc EMG Electrodiagn Med 2007;9(2):102-108.
Published online May 10, 2007.

Abstract

Objectives: To evaluate the usefulness of ipsilateral and contralateral motor evoked potentials (MEPs) in predicting functional recovery of upper limb in hemiplegic patients. Methods: Thirty eight right hemiplegic patients were assessed clinically by grip strength, tip pinch, lateral pinch, palmar pinch strength and Purdue pegboard performance (PPP), which represent the upper limb function, and electrophysiologically by ipsilateral and contralateral MEPs at first visit and after 2 months. The correlations between upper limb function and ipsilateral and contralateral MEPs were studied. Results: All patients showed improvement after 2 months in grip strength, tip pinch, lateral pinch, palmar pinch and PPP (p<0.05). The contralateral MEPs showed significant shortening in onset latency between patients' first visit and after 2 months (p<0.05) but, ipsilateral MEPs didn’t show significant changes (p<0.05). All groups whether MEP were induced or not in their first visits showed improvements in their 2 months follow up visits in upper limb functions (p<0.05). Conclusion: The recovery of upper limb function is related with onset latency of contralateral MEP test but not with that of ipsilateral MEP test. Therefore, contralateral MEP should be used as evaluation index of upper limb function.

Key Words: Hemiplegia, Ipsilateral MEPs, Contralateral MEPs, Upper limb function