Cervical spinal cord stimulation improved arm function in seven people with chronic post-stroke weakness

What happened

Seven people with profound arm and hand weakness after stroke (Fugl-Meyer Assessment scores of 15 to 35) had two stimulation leads placed on one side of the cervical spinal cord for four weeks. This paper reports the final outcomes of the study.

With stimulation switched on, motor function improved immediately regardless of how severe the impairment was: strength rose by 32% and Fugl-Meyer scores by 5.6 points on average. Three of the seven, who had residual corticospinal connections to finger muscles, improved hand and finger movement. Participants did only 8.6 hours of motor activity in total, 5.5 of them with stimulation on, yet ended the study an average of 6.6 Fugl-Meyer points above baseline. Spasticity decreased in all seven. No serious adverse events occurred.

Why it matters

Standard rehabilitation rarely delivers the high doses of practice needed for improvement in chronic stroke. A stimulator that assists movement directly, without an intensive therapy programme, could be developed into a fully implanted aid for daily use.

Caveats

This entry is based on the abstract and the limitations section of the full text. The trial had seven participants and leads implanted for only four weeks, so durability is unknown. The full text lists the absence of a control group as a limitation. The authors' suggestion that spared sensory function predicts response comes from a preliminary analysis.