My brain injury in 2000 affected my balance and gait. Doctors assessed it by asking me to walk across a small room and back again. Aside from that observational method, which would not have apprised them of my habit of veering to the curb or having to consciously move my legs to walk, no diagnostic tool was used to assess my balance. In addition, no clinic provided treatment. Both approaches failed me, although receiving neurostimulation in the form of brain biofeedback and audiovisual entrainment probably assisted my balance recovery.
Today, treatment is available.
The University of Wisconsin-Madison Tactile Communication and Neurorehabilitation Laboratory (TCNL) developed a prescription neuromodulation device that, along with tailored in-clinic and at-home training, improves or restores balance and gait. In 2018, Health Canada approved the Portable Neuromodulation System (PoNS) as a Class II non-implantable medical device for 14-week treatment for chronic balance deficit due to mild-to-moderate traumatic brain injury (TBI). Recently, the FDA did as well.
I became aware of neuromodulation of the brain through the tongue during a webinar hosted by the Brain Injury Society of Toronto after the COVID-19 pandemic started. PoNS therapy fills the gap in brain injury treatment by targeting balance and gait impairments caused by multiple sclerosis, TBI, bilateral vestibular loss, stroke, balance impairment, and spinal cord injury.
According to Dr. Norman Doidge, author of The Brain’s Way of Healing, neuromodulation is the brain’s internal ability to restore “the balance between excitation and inhibition in the neural networks.”
Neurostimulation can trigger neuromodulation, which improves brain regulation. The location of neurostimulation varies from treatment to treatment. The ones I’ve used stimulate through the eyes, ears, skin, and, directly but noninvasively, the brain. PoNS uses the tongue.
Why the tongue?
First, the mouth maintains a constant pH and temperature in a protected environment. Saliva is an excellent conduit for electrical impulses to travel from the PoNS’s electrode array along nerve fibers to the brain.
Second, according to a 2018 systemic study of the tongue, the tongue has an extensive and highly organized representation in “multiple levels in the brain (cortex, mesencephalon, medulla oblongata, and limbic system), with the highest specificity and integration reached at the cortical level.”
In a 2010 pilot study, Wildenberg et al. determined that “simple electrical tongue stimulation, devoid of exogenous environmental information, can produce sustained beneficial behavioral effects.” Previous studies had also found similar results “when evaluating the efficacy of electrical stimulation through the tongue coupled to head-position information.”
Placing the PoNS device on the anterior dorsal surface of the tongue stimulates noninvasively cranial nerve V (the trigeminal nerve) and cranial nerve VII (the facial nerve). The stimulated neurons transmit impulses to the brainstem (pons varolli and medulla) and the cerebellum. Through self-regulation, these brain areas change in accordance with the activity being conducted during neuromodulation of the cranial nerves.
These properties make the tongue an ideal site for PoNS neurostimulation. Apparently, the electrical impulses feel like champagne bubbles.
As with other neurostimulation and neuromodulation treatments, the authors found that clinicians must balance training so that it challenges the person to achieve maximum performance but does not tip the person into excessive fatigue. This approach of combining tasks or activities with neurostimulation accords with other approaches in restoring healthy function, such as with tDCS. Training comprises movement, balance, gait, cognitive, and breath work and awareness. Except for the warm-up exercises to wake up the brain, these activity components are done concurrently using the PoNS device.
Clinics using the PoNS device have determined the optimal training time per day for each segment of training. Therapy includes regular and progressive updates as clients improve and adapt so that the level of challenge remains constant relative to their improvement in order for the therapy to be beneficial.
Like other neurostimulation and neuromodulation therapies, PoNS therapy probably works across a range of injuries and diseases because it activates the modulated neural networks’ homeostatic regulation. Doidge noted in his 2015 book that TCNL had registered no side effects. This finding is consistent with other noninvasive neurostimulation and neuromodulation therapies, which have little to no side effects when prescribed and used in accordance with clinical advice.
Clinical research continues to prove the efficacy of this therapy.
Although they are not side effects, two issues counter accessing PoNS therapy: cost and the ability to follow the home training prescription.
Private insurance may cover (some of) the cost, but Medicare in Canada does not unless it’s part of in-hospital, outpatient rehabilitation. As far as I know, neurostimulation of any kind is not provided as part of standard Medicare-covered neurorehabilitation.
The bigger issue is that people with brain injury may not follow the home training as prescribed if they do not have support to keep them on task. To regenerate neurons and restore neural networks, treatment must challenge a person and be done for the full length of time required. This means more fatigue than one is used to will set in before time is up. As I found with Lindamood-Bell’s visualization and verbalization training (or any cognitively challenging task), the urge to quit grew to irresistible levels before I was halfway done. But the trainer knew how to keep me on task. Without that support, I may not have reached the required training time.
In addition, impatience with PoNS therapy may lead to skipping the warm-up exercises, and the environment may distract.
For these reasons, a person with brain injury who lives alone and/or has no support for at-home training may require the clinic to check in daily to encourage the client to fulfill their daily regimen to achieve the full benefit.
Learning about and brainstorming how a person with brain injury can receive PoNS therapy is one more way health care professionals can aid their clients, helping them to overcome as much as possible the deficits that brain injury incurred in them, leading to improved health, better quality of life, and, as a result, improved mental health.
Copyright ©2026 Shireen Anne Jeejeebhoy
