At the TIRR Memorial Hermann/UTHealth Spinal Cord Injury and Disability Research Center, Argyrios Stampas, MD, and his team are investigating the potential for home use of transcutaneous tibial nerve stimulation (TTNS) in patients with spinal cord injury. The research is funded by a TIRR Memorial Hermann Rehabilitation Innovations Award.
“Nearly everyone with spinal cord injury has some degree of bladder impairment, which researchers have identified as the number-one priority for improvement in quality of life with SCI,” says Dr. Stampas, an attending physician in the Spinal Cord Injury Program at TIRR Memorial Hermann and a clinical assistant professor in the department of Physical Medicine and Rehabilitation at McGovern Medical School at UTHealth. “The gold standard for treatment of neurogenic bladder involves the use of anticholinergic bladder medications, which have harmful side effects that ultimately lead to non-compliance. Evidence suggests that electric stimulation can produce the same results without the harmful side effects, but current practice is restricted to the clinic setting.”
In the clinic, percutaneous TNS is performed by trained healthcare technicians under physician supervision. They insert a needle into the skin to direct the electric current, a process that requires frequent clinic visits in a population with known accessibility challenges. Transcutaneous tibial nerve stimulation accomplishes the same result, using noninvasive surface electrodes. To date, the modality has been used only in the clinic setting.
Dr. Stampas’ research represents a substantive departure from the status quo by suggesting the use of TTNS at home to replace anticholinergic medications. “There’s a gap in our knowledge about the safety and feasibility of using TTNS at home for bladder neuromodulation in patients with SCI,” he says. “Our current study is based on the hypothesis that TTNS can be performed at home by those with SCI or their caregivers, and will lead to decreased use of bladder medication. It will also provide a dignified treatment for neurogenic bladder that can improve quality of life.”
A safe, affordable, lifelong TTNS program that can be used by people with SCI at home would significantly change life for the more than 1 million people living with spinal cord injury and its associated functional impairments. The researchers are currently applying the TTNS protocol to acutely injured SCI patients during inpatient rehabilitation, with application of electrodes by a research assistant. In an ongoing study with 19 participants, they reported 100 percent compliance and tolerability, no changes in pain scores during and after treatment, and no adverse events such as urinary tract infections or skin irritation.
“Preliminary data suggests that the control group followed the expected course of neurogenic bladder over time, with more bladder spasms, higher pressures and lower bladder capacity,” Dr. Stampas says. “The stimulation group has not followed this path. Based on this pilot data, we believe the TTNS protocol can be replicated at home by people with SCI or their caregivers and improve continence.”
Fourteen people with chronic SCI who perform intermittent indwelling catheterization will be recruited for the study. After the first week, they will be asked to discontinue their medication and rely solely on TTNS for three weeks to remain continent.
“We expect our work to generate preliminary data that will fundamentally increase our knowledge of TTNS in chronic neurogenic bladder and guide future studies on lifelong management of neurogenic bladder with TTNS,” Dr. Stampas says. “In a population known to have low financial resources and barriers to accessing medical care, we see this as an opportunity to develop a cost-saving intervention that will be sustainable at home."