Bi-hemispheric Repetitive Transcranial Magnetic Stimulation for Upper Limb Motor Recovery in Chronic Stroke: A Feasibility Study

Journal: Brain Stimulation 11(4):932-934 (2018)

Authors: R Chieffo, G Scopelliti, M Fichera, R Santangelo, S Guerrieri, A Zangen, G Comi, L Leocani

Background:

The emerging crucial role of non-primary and contralesional motor areas in the recovery of upper extremity (UE) after acute stroke led to the proposal of the “bimodal-balance recovery model”, with the hypothesis that the contribution of ipsi-and contralesional primary and secondary motor areas might vary according to the structural reserve of the ipsilesional cortico-spinal tract. This model offers itselfto novel non-invasive brain stimulation approaches for improving the effects of neurorehabilitation, targeting bilateral, wide motor cortical regions rather than focusing on the ipsilateral or contralesional M1.

Objective:

To test the safety, feasibilityand efficacy of simultaneous high-frequency rTMS of bilateral motor/premotor areas using the H5-coil, associated with unilateral motor training of the paretic UE.

Methods:

Twenty patients with UE motor involvement from first-ever chronic stroke under went 11 sessions of 30 minutes of upper limb motor training (MT) of the paretic UE, each followed by rTMS with the symmetric H5-coil, designed to stimulate both hemispheres simultaneously(40 2s-trains at 20 Hz, 20 sec inter-train interval, 1600 pulses), at 90% of resting motor threshold (RMT). Clinical measurements were collected before the first (T0) and after the last treatment session (T1), plus one-month follow-up (T2) and included: FM-UE score, modified Ashworth scale (MAS) global score as the sum of shoulder, elbow and wrist scores (range 0-12), hand grip strength (JAMAR dynamometer).

Results:

In this study that included participants with mild to severe-moderate UE motor impairment, bilateral high-frequency rTMS of motor/premotor areas, following motor training, was associated with greater and more sustained motor improvement compared with motor training followed by sham. Such improvement was clinically relevant (FM-UE6 point) for 70% of subjects in the real group (vs 10%of the sham group).Interestingly, the investigators found that bilateral stimulation of motor/premotor areas was associated with a greater FM-UE improvement in more severely impaired patients, opposite to what observed in the sham group.

Conclusions:

It is possible that the wide bilateral, simultaneous stimulation may improve functional intra-and interhemispheric synchronization between motor and premotor areas and promote the unmasking of cortico-cortical and descending pathways

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