Efficacy of repetitive transcranial magnetic stimulation for gait disturbance in HTLV-1 associated myelopathy

Abstract

BACKGROUND: Human T-cell leukemia virus type 1 (HTLV-1) associated myelopathy (HAM) can damage the spinal cord, causing paraplegia, spasticity, and gait disturbance. Currently, there are few effective treatments. OBJECTIVE: We investigated the efficacy of repetitive transcranial magnetic stimulation (rTMS) on gait disturbance in patients with HAM. METHODS: rTMS at 10 Hz was applied to HAM patients aged 30–80 years with an Osame’s Motor Disability Score between 3 and 6. The stimulation site on the skull was the position where motor evoked potentials were most evidently elicited and leg motor areas were stimulated. Resting motor thresholds (minimum stimulation to induce motor evoked potential) were also determined. Each participant underwent 10 sessions of 2400 stimuli. Clinical measurements, including walking speed and stride length, were obtained. RESULTS: From 119 patients with HAM recruited, 12 were included in the rTMS group and 18 who did not undergo rTMS comprised the control group. rTMS significantly improved walking speed and stride length compared to controls. Particularly, resting motor thresholds decreased after 10 sessions of rTMS. CONCLUSIONS: rTMS improves walking speed in patients with HAM and may be an effective alternative for treating gait disturbance in patients with HAM.