Introduction: Repetitive transcranial magnetic stimulation (rTMS) treatment of ipsilesional (IL) or contralesional (CL) cortex combined with occupational/physical therapy (OT/PT) shows significant promise in chronic ischemic stroke (CIS). Here we describe a multifocal cortical magnetic stimulation protocol with a new wearable device called transcranial rotating permanent magnet stimulator (TRPMS) for a pilot clinical trial in CIS, and present preliminary results in one patient.
Hypothesis: Simultaneous repeated excitatory and inhibitory stimulations of IL and CL cortical sites, respectively cause perilesional functional cortical reorganization with recovery of motor function in CIS.
Methods: After informed consent, we treated a 58-year old male patient with a right middle cerebral artery thromboembolic infarct causing left sided hemiparesis. At the start of TRPMS treatment 19 months after the stroke he had a stable baseline on motor function tests. The treatment consisted of 4 two-week sessions (with intervening one-week rest periods) of daily (on week days) 40 min TRPMS stimulation (5 Hz, 25 ms pulse duration at 4 perilesional cortical sites, and 0.2 Hz, 100 ms pulse duration at 2 CL primary motor cortical sites) accompanied by OT/PT. Pretreatment, posttreatment and follow-up assessments were functional magnetic resonance imaging (fMRI) during attempted gripping movements, and grip strength, gait speed and Fugl-Meyer (FM) scale testing.
Results: After the 2nd treatment session movement-related fMRI showed increasing levels of neural activation of the stimulated intact cortex surrounding the lesion. Grip strength of the affected hand increased ~2.5 fold. Gait speed increased by ~15%. Left lower extremity motor function and sensation measures on the FM scale showed sustained increase by ~17% and ~30%, respectively. These changes persisted above the pretreatment levels at the 3-month follow-up. There were no adverse effects.
Conclusions: These findings suggest that the new TRPMS protocol might bring about some degree of functional cortical reorganization and motor recovery in CIS. We have therefore launched a randomized double-blind sham treatment-controlled clinical trial involving a four-week TRPMS treatment in 30 CIS patients.