James H. Semans

Electrical Stimulation of the Conus medullaris in the Paraplegic

In 1970 we carried out the first electrode implantation of the conus medullaris of a 17-year-old male paraplegic to control the emptying of his paralyzed bladder. Our patient has used electromicturition for 6 years to successfully empty his bladder and prevent urinary infection. To date, a total of 11 paraplegic patients have been implanted (6 males, 5 females). The cause of the paraplegia was the result of trauma, and the implants were performed from 16 days to 15 years postinjury. All the patients had experienced numerous urinary infections and required constant catheter drainage, and it was the opinion of our urologic associate that current methods of control of the bladder problem were of no avail. The bladder was considered to be atonic in 7 patients and spastic in 4. The results indicate that after a follow-up of 1--6 years, 8 patients have complete control of voiding by electrical stimulation (4 female, 4 male). 2 of the males required partial sphincterotomy to improve emptying, but none of the females experienced sphincter interference. One male quadriparetic patient died 7 months postimplantation of pneumonia and hepatitis. There have been no infections related to the implantable device; however, 1 female broke the connecting wires to the spinal cord electrode during a paraplegic basketball game. In addition to the induced electrical contraction of the bladder, we have observed increased autonomic activity below the level of the spinal cord transection, improved defecation, reduction of spasticity in the paralyzed legs, penile erection in males, and reduction of decalcification of the long bones. This group of patients represents the longest use of an implantable electronic device to control bladder function.