ID 12 - Cortical recovery from primary motor cortex (stroke) infarction evaluated at chronic stage

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• 作者：P. Julkunen^a ; ^b ; L. Sä ; isä ; nen^a ; S. Mä ; ä ; ttä ; ^a ; M. Kö ; nö ; nen^a ; ^c ; E. Kallioniemi^a ; ^b ; R. Vanninen^c ; P. Jä ; kä ; lä ; ^d ; S. Vaalto^e
• 刊名：Clinical Neurophysiology
• 出版年：2016
• 出版时间：March 2016
• 年：2016
• 卷：127
• 期：3
• 页码：e79
• 全文大小：37 K

文摘

To assess function of the motor cortex in chronic stroke patients who had suffered a restricted focal ischemic lesion affecting primarily anatomical hand representation.

Methods

Eight patients (48–68 years) exhibiting little or no motor impairment were studied 2 years after stroke using navigated transcranial magnetic stimulation (TMS). Both hemispheres were studied for the muscle recruitment characteristics of hand muscles using motor evoked potentials (MEPs). MEP-amplitudes were assessed to estimate resting motor threshold (rMT) for 50 μ$\mathrm{\mu }$V and 2 mV thresholds. Short-interval intracortical inhibition (SICI) was investigated with paired-pulse TMS using interstimulus intervals of 2 ms and 3 ms.

Results

The rMTs did not differ between the intact and lesioned hemispheres in 50μ$\mu$V responses (p >$>$ 0.999), while the rMT for 2 mV responses was higher (p = 0.018) and MEP-amplitudes induced at 120%rMT were lower (p = 0.008) in the lesioned hemisphere indicating inability to recruit enough motor units to produce high amplitude responses. SICI was absent on the lesioned hemisphere and apparent on the intact hemisphere (p = 0.008).

Conclusions

In small focal ischemic lesions, associated with mild motor impairment, TMS is sensitive enough to specify the loss of motoneurons.

Key message

Neurophysiological motor function recovery is incomplete years after the stroke even though clinical symptoms are largely normalized.