Magnetic stimulation helps stroke rehab

As a rehabilitation technique for stroke, repetitive magnetic stimulation of the brain (rTMS) improves patient movement on the side of the body affected by the stroke.With rTMS, a magnet is used to slow nerve activity on the side of the brain not affected by the stroke. Previous research has suggested that after a stroke, the unaffected side becomes hyperactive, sending signals to the affected side that actually impair the patient's ability to move the arms and legs.Researchers from Harvard Medical School in Boston, USA, studied 15 patients who were randomly selected to undergo active or fake rTMS, applied to the unaffected side of the brain. Patient movement and brain activity were assessed before, during, and after treatment.

It was found that active rTMS was associated with significant improvements in movement in the affected hand over the study period, but no improvements were seen with the fake rTMS. At the same time, brain activity decreased in the unaffected side, and it increased in the affected side in the active treatment patients. In a simple reaction-time task, patients were an average of 30 percent faster after five days of rTMS and the effect persisted for 2 weeks. Interestingly, the improvement was cumulative. Patients were, on average, 10, 20, 27, and 30 percent faster on days two, three, four, and five, respectively. These movement improvements were significant compared to fake stimulation.The findings indicate that the magnitude and duration of movement benefits can be safely increased after more than one rTMS session. With five consecutive sessions, sustained improvements in movement in stroke patients were noted over the 2-week study period. There was no evidence that five sessions of rTMS adversely affected the patients' thinking ability or promoted seizures.

The researchers call for larger studies to replicate their findings and to maximize response to treatment.

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