Effects of repetitive transcranial magnetic stimulation on lower extremity spasticity and motor function in stroke patients

Abstract

Purpose: To investigate the effect of low-frequency repetitive transcranial magnetic stimulation (rTMS) on lower extremity (LE) spasticity, motor function and motor neurone excitability in chronic stroke patients.

Method: This study was a randomised sham-controlled cross-over trial with 1-week follow-up. A total of 20 post-stroke patients were randomised to receive active (n = 10) or sham (n = 10) rTMS. Fourteen of them (7 in each group) crossed over to the sham or active rTMS after a washout period of 1 month. Interventions consist of five consecutive daily sessions of active or sham rTMS to the unaffected lower extremity motor area (1000 pulses; 1 Hz; 90% of the tibialis anterior motor threshold). Outcome measures were modified modified ashworth scale (MMAS), the H-reflex, lower extremity section of Fugl–Mayer assessment (LE-FMA) and timed UP and GO (TUG) test. All outcomes were measured at three levels in each intervention period: pre- and post-intervention and 1-week follow-up.

Results: Friedman’s test revealed significant improvement in MMAS score only after active rTMS. This improvement lasted for one week after the active rTMS. Repeated measure analysis of variance (ANOVA) showed significant time*intervention interaction for LE-FMA. There are no differences between groups for the MMAS and LE-FMA. No significant change in H_max/M_max ratio and TUG test was noted.

Conclusion: Low-frequency rTMS over the LE motor area can improve clinical measures of muscle spasticity and motor function. More studies are needed to clarify the changes underlying this improvement in spasticity.

Implications for Rehabilitation

• Spasticity is a common disorder and one of the causes of long-term disability after stroke.

• Physical therapy modalities, oral medications, focal intervention and surgical procedures have been used for spasticity reduction.

• Beneficial effect of the repetitive transcranial magnetic stimulation (rTMS) for post-stroke upper extremity spasticity reduction and motor function improvement was demonstrated in previous studies.

• This study shows amelioration of lower extremity spasticity and motor function improvement after five daily sessions of inhibitory rTMS to the unaffected brain hemisphere which lasted for at least 1 week following the intervention.

Keywords:

• H-reflex
• motor function
• repetitive transcranial magnetic stimulation
• spasticity
• stroke

Acknowledgements

Special thanks to the Department of Physical Medicine and Rehabilitation of Firozgar University Hospital for their kind cooperation.

Declaration of interest

The authors report no conflict of interest. This study was done by the financial support from the Research Deputy, Tehran University of Medical Sciences.