Motor Evoked Potentials in the Upper Extremities of Children with Spastic Hemiplegic Cerebral Palsy

The aim of this study was to evaluate and compare the reorganization of corticospinal pathways innervating upper extremity muscles in patients with spastic hemiplegic cerebral palsy (CP). Thirty-2 patients (17 male, 15 female) with spastic hemiplegic CP were enrolled. The average age (mean ± standard deviation) was 7.5 ± 4.6 (range: 2–17) years. Transcranial magnetic stimulation (TMS) was applied to the unaffected and affected motor cortices in turn, and bilateral electromyographic recordings were made from the first dorsal interossei (FDI), the biceps brachii (BB), and the deltoid muscles during rest. The onset latency, central motor conduction time, and peak-to-peak amplitude of motor evoked potentials (MEPs) were measured for each muscle bilaterally. Whilst TMS of both affected and unaffected hemispheres elicited contralateral MEPs in all muscles, the number of MEPs evoked from the affected hemisphere was less than from the unaffected hemisphere for FDI and BB. TMS responses to stimulation of the affected side showed prolonged latency and reduced amplitude. The amplitudes of MEPs increased with age whereas the latencies were relatively constant. These results suggest that the corticospinal pathways to the proximal and distal muscles of the upper extremity undergo sequential maturation and reorganization patterns.

Ten-Year Follow-Up of Transcranial Magnetic Stimulation Study in a Patient With Congenital Mirror Movements: A Case Report

Most studies concerning congenital mirror movements (CMMs) have been focused on the motor organization in the distal hand muscles exclusively. To the best of our knowledge, there is no data on motor organization pattern of lower extremities, and a scarcity of data on the significance of forearm and arm muscles in CMMs. Here, we describe the case of a 19-year-old boy presenting mirror movements. In these terms, a 10-year transcranial magnetic stimulation study demonstrated that the motor organization pattern of the arm muscles was different from that of distal hand and forearm muscles even in the same upper extremity, and that the lower extremities showed the same pathways as healthy children. Moreover, in this case, an ipsilateral motor evoked potentials (MEPs) for distal hand muscles increased in amplitude with age, even though the intensity of mirror movements decreased. In the arm muscles, however, it was concluded that the contralateral MEPs increased in amplitude with age.