N-of-1 Trial of Electrical Sensory Stimulation Therapy on the Tibial Innervated Area during Gait in a Case of Post-stroke Sensory Disturbance

BACKGROUND: Transcutaneous electrical sensory nerve stimulation (TESS) is used to enhance the recovery of sensorimotor function in post-stroke hemiparesis. However, TESS efficacy for post-stroke gait disturbance remains unknown. We hypothesized that TESS on the area innervated by the tibial nerve, targeting the superficial plantar sensation, combined with gait training would improve gait function in patients with gait disturbance caused by severe superficial sensory disturbance after stroke. CASE: A 42-year-old man was referred to the convalescent rehabilitation hospital 4 months after a left pontine hemorrhage. He showed severe superficial sensory disturbance without motor paresis in the right lower leg and planta pedis. Gait training with TESS on the tibial nerve innervated area was performed, targeting plantar sensation according to an N-of-1 study design of a single-case ABCAB that included two 10-min sessions of gait training without TESS (phase A), two gait training sessions with TESS targeting the right plantar sensation (phase B), and one session with TESS targeting the upper leg sensation as control (phase C). The patient showed increased gait distance and stride length, improved superficial sensation on the right planta pedis, and improved balance after phase B, but not after phases A and C. DISCUSSION: Gait training with TESS on the tibial nerve innervated area improved gait ability, superficial plantar sensation on the targeted side, and balance function in a post-stroke patient with sensory disturbance. Gait training with TESS may be effective for gait dysfunction caused by sensory disturbance in patients with central nervous system disorders.