Low-frequency antidromic pelvic neuromodulation as a potential enhancer of recovery after spinal cord injury: hypothetical promotion of spinal Renshaw cells and corticovagal plasticity.

Objectives: In all patients, LFAS To explore the effect of low frequency antidromic stimulation (LFAS) of the pelvic somatic serves on intestinal peristalsis and heart rate in individuals with chronic spinal cord ird injury and spasticity.

Setting: Hospital in Zürich, Switzerland.

Methods: Ten consecutive patients underwent laparoscopic implantation of neuroprosthesis to sciatic/femoral nerves - the LION procedure: 5 patients with Thoracic (T) SCI AIS A, 1 patient T4 AIS C, 1 patient C3 AIS A, and 3 patients with cervical injury (AIS B/C). At the end of the implantation, intestinal peristalsis observed laparoscopically was recorded before and after starting with LFAS at 10 Hz. On the first postoperative day, heart rates before and after the beginning of the same LFAS were checked. Statistical analyses were performed using a paired Student's t-test.

Results: LFAS Of the pelvic somatic nerves induced strong peristalsis in the small bowel and ascending/transverse colon without affecting the urinary bladder or descending colon/rectum, and a significant slowing of the heart rate in 8 patients with an overall reduction from 96.3 bpm (bpm) (P < 0.01).

Conclusions: This case series study reports on the effect of continuous antidromic pelvic neuromodulation (CAPN) on extraspinal somatic and autonomic pathways in chronic SCI. The discussion poses a novel hypothesis about the effect of CAPN on spinal pathways and activation of corticospinal pathways and neuroplasticity via the Renshaw cells. A rationale is provided for CAPN-induced activation of the vagus nerve (VN) and the existence of anastomotic pathways between the lumbosacral somatic nerves and the VN, and the capability of an activation of the motor functions of the VN. A second hypothesis is posed for the activation of cortico-vagal plasticity that may improve recovery after complete SCI by combining CAPN with neuromodulation of the VN.Trial registration NCT03441256.