Deep Repetitive Transcranial Magnetic Stimulation with H-coil on Lower Limb Motorfunction after Stroke: a Pilot Study

Journal: Archives of Physical Medicine and Rehabilitation95:1141-7(2014)

Authors: R Chieffo, S De Prezzo, E Houdayer, A Nuara, G Di Maggio, E Coppi, L Ferrari, L Straffi, F Spangnolo, S Velikova, M Sessa, M Comola, A Zangen, G Comi, L Leocani

Background:

Stroke is a leading cause of long term disability and non-invasive brain stimulation techniques have been recognized as a promising intervention for the treatment of post-stroke motor deficits. Although the ability to walk is impaired in more than 80% of post-stroke subjects, the pathophysiological reorganization of lower limb motor areas after stroke is still unclear as relatively fewer data are available compared with the upper extremity.The lower limb cortical motor areas are located deeply in the mesial cortical surface of the hemispheres. The H-coil, that effectively stimulates at a depth of about 3-5 cm below the skull, has been reported to require lower intensities of stimulation to obtain lower limb motor responses.

Objective:

To assess the efficacy of bilateral excitatory high frequency (20 Hz) stimulation over the lower limb motor area on lower limb motor function in subjects with chronic (> 6 months) subcortical stroke in a double-blind, placebo-controlled crossover study.

Methods:

This was a double-blind, placebo controlled, crossover study. Ten right-handed subjects affected by a first-ever subcortical stroke more than 6 months prior participated in the study. Deep TMS was delivered with an H-Coil targeting the lower limbs motor cortex representation. Each subject received both real and sham Deep TMS according to a random sequence crossover design. The two TMS cycles (real or sham) were composed of 11 sessions each, administered over 3 weeks and separated by a 4-week washout period.Lower limb functions were assessed by the lower limb Fugl-Meyer Assessment (FMA), used to evaluate and measure recovery in post-stroke patients, the 10-m walk test, and the 6-minute walk test, before and 1 day after the end of each treatment period, as well as at a 4-week follow-up.

Results:

Real rTMS treatment was associated with a significant improvement in lower limb. This effect persisted over time (follow-up) and was significantly greater than that observed with sham stimulation. A significant increase in walking speed was also found after real rTMS but this effect did not reach statistical significance in comparison with the sham stimulation.

Conclusions:

These data demonstrated that 3 weeks of high-frequency deep rTMS could induce long-term improvements in lower limb functions in the chronic post-stroke period, lasting at least 1 month after the end of the treatment.

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