Repetitive transcranial magnetic stimulation (rTMS) has been widely explored as a tool for treating a variety of disorders, including depression (Martin et al. 2003; Couturier et al. 2005), pain (Lima & Fregni 2008), and motor disorders following Parkinson’s disease (Elahi et al. 2009) and stroke (Corti et al. 2011). Experimental studies in humans have shown that low frequency rTMS (<1 Hz) can reduce the excitability of the motor cortex whereas high frequency rTMS (>1 Hz) causes an increase in motor cortical excitability (Kobayashi & Pascual-Leone 2003). Given the ability for rTMS to modulate cortical excitability, there has been much interest in exploring its potential to facilitate supraspinal connectivity or restore the balance of interhemispheric inhibition (in stroke) as a means to promote motor recovery and function.
The recovery of functional ambulation following motor-incomplete SCI has been shown to be associated with enhanced excitability of motor cortical areas (Winchester et al. 2005) and corticospinal connectivity to the lower limb (Thomas & Gorassini 2005). Recently, Kumru et al. (2013) explored the potential efficacy of combining rTMS with locomotor training on gait outcomes in people with sub-acute (<12 months) motor-incomplete SCI (ASIA D). Seventeen subjects were randomized to either a control group with sham stimulation, or the rTMS group. Stimulation (sham or rTMS) was delivered while subjects lay supine, 5 times/week for 3 weeks. All subjects also received daily overground gait training for 1 hour for 3 weeks. The gait training session was performed within 30 minutes of the stimulation session. There was an additional 2 weeks of overground gait training only as a follow-up.
There were no adverse events reported from one RCT study (Kumru et al. 2013). In this study, both groups were comparable on all outcome measures at baseline, except for the modified Ashworth scale, which was lower in the sham stimulation group. Although the authors report significant within-group changes in LEMS and 10MWT in the rTMS group, but not the sham stimulation group, there were actually no significant between-group differences at the end of the 3-week training period. Both groups were comparable in the LEMS, 10MWT, TUG, WISCI-II, MAS, and SCI-SET. Analysis of the change scores after 3 weeks of training revealed significant improvements only in the LEMS and MAS, but baseline function was not taken into account in the statistical model.
There is level 1b evidence from one RCT (Kumru et al. 2013) that rTMS combined with overground locomotor training may not afford further benefits over overground locomotor training alone (with sham stimulation).
- rTMS combined with overground locomotor training may not afford further benefits over overground locomotor training alone.