Scientists have restored bladder control in patients with spinal cord injury, helping them urinate voluntarily, using a non-invasive and painless magnetic device.
In a small experimental study, neuroscientists stimulated the lower spinal cord (through the skin) with a magnetic device placed at the lumbar spine.
After only four sessions of mild magnetic stimulation spread out over four weeks, five male participants recovered significant bladder control.
The men had had spinal cord injuries for between five to 13 years, and had to use a catheter (a narrow tube slid into the bladder to drain urine) several times a day. Those who had injuries that impaired the use of their hands had to depend on a caregiver to insert the catheter.
Long-term catheter use can introduce bacteria, leading to urinary tract infections and permanent scarring. Bladder problems after spinal cord injuries can also lead to kidney failure and death.
Seeking to eliminate the need for catheters and their associated risks, researchers stimulated the spinal cord with a magnetic device, to access the cellular machinery that controls urination. (The magnetic device is approved by the US Food and Drug Administration for human use, though not for bladder rehabilitation, as was the case in this experiment).
“Most spinal cord injuries are not anatomically complete; the spinal cord retains a weak residual connection with the brain. By amplifying these faint signals and enhancing the spinal circuits’ ability to respond to them, we are restoring bladder function,” explained principal investigator Dr Daniel Lu.
Each participant got 15 minutes of weekly stimulation for four months. At first, there were no results, but after four sessions, there was measurable improvement and the benefit persisted for two to four weeks, suggesting that the spinal cord’s neural circuitry retains a memory of the treatment.
“All five men regained the ability to urinate on their own during stimulation. In one case, the patient was able to completely stop using a catheter and empty his bladder several times a day, up to four weeks after his last treatment,” said Dr Lu, adding that the men’s quality of life (based on a “before and after” questionnaire) improved by an average of 60 per cent.
While the ability to urinate at will improved in each patient, four still had to use a catheter at least once a day, but that was still a significant drop from more than six times a day before the treatment.
Moreover, the patients’ average bladder capacity increased from 244 millimetres to 404 millilitres, and the volume of urine they produced voluntarily rose from zero to 1,120 cubic centimetres a day.
The researchers plan to evaluate the approach with a larger number of men and women, to gain deeper understanding of how magnetic stimulation alters neural activity in the spinal cord.
They will also explore whether different stimulation patterns improve response in patients who didn’t benefit to the same degree as others in this study.
The technique, which was described in the journal Scientific Reports, could help reduce the social stigma associated with frequent catheter use.