A Prospective, Multicenter Study to Assess the Safety and Efficacy of Translingual Neurostimulation Plus Physical Therapy for the Treatment of a Chronic Balance Deficit Due to Mild-to-Moderate Traumatic Brain Injury

Improvement in gait and functional abilities in an adult with posterior cortical atrophy after translingual neuromodulation with neurorehabilitation physical therapy: a case report

BACKGROUND

Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterized by progressive damage to the brain's visual and association areas, resulting in impaired spatial awareness, visual processing, and functional independence.

PURPOSE

This report examines the effects of a 14-week treatment protocol consisting of translingual neuromodulation via a portable neuromodulation stimulator (PoNS®1) in conjunction with physical therapy on balance, gait, and functional mobility in an adult male with PCA.

CASE DESCRIPTION

Assessments included objective and subjective measures of balance and gait - the 10-Metre Walk Test, Functional Gait Assessment (FGA), Dynamic Gait Index (DGI), Community Balance and Mobility Scale (CB&M), Neuro-Quality of Life (Neuro-QoL), and Activities-specific Balance Confidence (ABC) Scale. These were performed at baseline and weeks 4, 8, and 14 to evaluate the protocol's efficacy in improving balance, stability, and gait.

OUTCOMES

Postural stability, balance, gait patterning, and gait speed improved, enhancing daily functioning abilities and self-confidence. Gait speed improved by 0.48 m/s (comfortable) and 0.46 m/s (fast), exceeding MDC thresholds. The participant's FGA score increased 21 points and DGI increased 17 points, both exceeding their respective MDC thresholds (6 points for FGA, 3.2 points for DGI), reflecting marked gait improvements. The CB&M score rose 24 points, exceeding the MDC of 9.6 points. Despite these gains, gait speed remained below age-related norms.

CONCLUSION

Given the largely positive response to the protocol, further investigation should be undertaken to continue to explore the efficacy of PoNS® and physical therapy to determine its viability as a treatment for symptoms of PCA.

Translingual neural stimulation induced changes in intra- and inter-network functional connectivity in mild-moderate traumatic brain injury patients

Introduction

Mild-to-moderate traumatic brain injury (mmTBI) that lead to deficits in balance and gait are difficult to resolve through standard therapy protocols, and these deficits can severely impact a patient's quality of life. Recently, translingual neural stimulation (TLNS) has emerged as a potential therapy for mmTBI-related balance and gait deficits by inducing neuroplastic changes in the brain gray matter structure. However, it is still unclear how interactions within and between functional networks in brain are affected by TLNS. The current study aimed to extend our previous resting-state functional connectivity (RSFC) study investigating the effects of TLNS intervention on outcome measures related to gait and balance.

Methods

An experimental PoNS device was utilized to deliver the TLNS. The 2-week TLNS intervention program, specifically stimulation during focused physical therapy focused on recovery of gait and balance, included twice-daily treatment in the laboratory and the same program at home during the intervening weekend. The resting-state fMRI datasets at pre- and post-interventions were collected by 3T MRI scanner with nine mmTBI patients. All participants also received both Sensory Organization Test (SOT) and Dynamic Gait Index (DGI) testing pre- and post-intervention as part of the behavioral assessment.

Results

Compared to baseline, TLNS intervention led to statistically significant improvements in both the SOT [t (8) = 2.742, p = 0.028] and the DGI [t (8) = 2.855, p = 0.024] scores. Moreover, significant increases in intra- and inter-network RSFC were observed, particularly within the visual, default mode, dorsal attention, frontoparietal (FPN), and somatosensory (SMN) networks. Additionally, there were significant correlations between the SOT and inter-network FC [between FPN and SMN, r (9) = -0.784, p = 0.012] and between the DGI and intra-network FC [within SMN, r (9) = 0.728, p = 0.026].

Discussion

These findings suggest that TLNS intervention is an effective in increasing somatosensory processing, vestibular-visual interaction, executive control and flexible shifting, and TLNS may be an effective approach to inducing brain network plasticity and may serve as a potential therapy for mmTBI-related gait and balance deficits.

ALSUntangled #75: Portable neuromodulation stimulator therapy

Spurred by patient interest, ALSUntangled herein examines the potential of the Portable Neuromodulation Stimulator (PoNS™) in treating amyotrophic lateral sclerosis (ALS). The PoNS™ device, FDA-approved for the treatment of gait deficits in adult patients with multiple sclerosis, utilizes translingual neurostimulation to stimulate trigeminal and facial nerves via the tongue, aiming to induce neuroplastic changes. While there are early, promising data for PoNS treatment to improve gait and balance in multiple sclerosis, stroke, and traumatic brain injury, no pre-clinical or clinical studies have been performed in ALS. Although reasonably safe, high costs and prescription requirements will limit PoNS accessibility. At this time, due to the lack of ALS-relevant data, we cannot endorse the use of PoNS as an ALS treatment.

Trigeminal nerve stimulation: a current state-of-the-art review

Nearly 5 decades ago, the effect of trigeminal nerve stimulation (TNS) on cerebral blood flow was observed for the first time. This implication directly led to further investigations and TNS' success as a therapeutic intervention. Possessing unique connections with key brain and brainstem regions, TNS has been observed to modulate cerebral vasodilation, brain metabolism, cerebral autoregulation, cerebral and systemic inflammation, and the autonomic nervous system. The unique range of effects make it a prime therapeutic modality and have led to its clinical usage in chronic conditions such as migraine, prolonged disorders of consciousness, and depression. This review aims to present a comprehensive overview of TNS research and its broader therapeutic potentialities. For the purpose of this review, PubMed and Google Scholar were searched from inception to August 28, 2023 to identify a total of 89 relevant studies, both clinical and pre-clinical. TNS harnesses the release of vasoactive neuropeptides, modulation of neurotransmission, and direct action upon the autonomic nervous system to generate a suite of powerful multitarget therapeutic effects. While TNS has been applied clinically to chronic pathological conditions, these powerful effects have recently shown great potential in a number of acute/traumatic pathologies. However, there are still key mechanistic and methodologic knowledge gaps to be solved to make TNS a viable therapeutic option in wider clinical settings. These include bimodal or paradoxical effects and mechanisms, questions regarding its safety in acute/traumatic conditions, the development of more selective stimulation methods to avoid potential maladaptive effects, and its connection to the diving reflex, a trigeminally-mediated protective endogenous reflex. The address of these questions could overcome the current limitations and allow TNS to be applied therapeutically to an innumerable number of pathologies, such that it now stands at the precipice of becoming a ground-breaking therapeutic modality.

Real world evidence of improved attention and cognition during physical therapy paired with neuromodulation: a brain vital signs study

Background

Non-invasive neuromodulation using translingual neurostimulation (TLNS) has been shown to advance rehabilitation outcomes, particularly when paired with physical therapy (PT). Together with motor gains, patient-reported observations of incidental improvements in cognitive function have been noted. Both studies in healthy individuals and case reports in clinical populations have linked TLNS to improvements in attention-related cognitive processes. We investigated if the use of combined TLNS/PT would translate to changes in objective neurophysiological cognitive measures in a real-world clinical sample of patients from two separate rehabilitation clinics.

Methods

Brain vital signs were derived from event-related potentials (ERPs), specifically auditory sensation (N100), basic attention (P300), and cognitive processing (N400). Additional analyses explored the attention-related N200 response given prior evidence of attention effects from TLNS/PT. The real-world patient sample included a diverse clinical group spanning from mild-to-moderate traumatic brain injury (TBI), stroke, Multiple Sclerosis (MS), Parkinson's Disease (PD), and other neurological conditions. Patient data were also acquired from a standard clinical measure of cognition for comparison.

Results

Results showed significant N100 variation between baseline and endpoint following TLNS/PT treatment, with further examination showing condition-specific significant improvements in attention processing (i.e., N100 and N200). Additionally, CogBAT composite scores increased significantly from baseline to endpoint.

Discussion

The current study highlighted real-world neuromodulation improvements in neurophysiological correlates of attention. Overall, the real-world findings support the concept of neuromodulation-related improvements extending beyond physical therapy to include potential attention benefits for cognitive rehabilitation.

Neurostimulation for Traumatic Brain Injury: Emerging Innovation

Traumatic brain injury (TBI) is a significant source of brain deficit and death among neurosurgical patients, with limited prospects for functional recovery in the cases of moderate-to-severe injury. Until now, the relevant body of literature on TBI intervention has focused on first-line, invasive treatment options (namely craniectomy and hematoma evacuation) with underwhelming focus on non-invasive therapies following surgical stabilization. Recent advances in our understanding of the impaired brain have encouraged deeper investigation of neurostimulation strategies, owed largely to its demonstrated livening of damaged neural circuitry and capacity to stabilize erratic network activity. The objective of the present study is to provide a scoping review of new knowledge in neurostimulation published in the PubMed, Scopus, and Google Scholar databases from inception to November 2022. We critically assess and appraise the available data on primary neurostimulation delivery techniques, with marked emphasis on restorative opportunities for accessory neurostimulation in the interdisciplinary care of moderate-to-severe TBI (msTBI) patients. These data identify two primary future directions: 1) to relate obtained gain-of-function outcomes to hemodynamic and histological changes and 2) to develop a clearer understanding of neurostimulation efficacy, when combined with pharmacologic interventions or other modulatory techniques, for complex brain insult.

Translingual neural stimulation affects resting-state functional connectivity in mild-moderate traumatic brain injury

BACKGROUND AND PURPOSE

Traumatic brain injury (TBI) can lead to movement and balance deficits. In addition to physical therapy, brain-based neurorehabilitation efforts have begun to show promise in improving these deficits. The present study investigated the effectiveness of translingual neural stimulation (TLNS) on patients with mild-to-moderate TBI (mmTBI) and related brain connectivity using a resting-state functional connectivity (RSFC) approach.

METHODS

Resting-state images with 5-min on GE750 3T scanner were acquired from nine participants with mmTBI. Paired t-test was used for calculating changes in RSFC and behavioral scores before and after the TLNS intervention. The balance and movement performances related to mmTBI were evaluated by Sensory Organization Test (SOT) and Dynamic Gait Index (DGI).

RESULTS

Compared to pre-TLNS intervention, significant behavioral changes in SOT and DGI were observed. The analysis revealed increased RSFC between the left postcentral gyrus and left inferior parietal lobule and left Brodmann Area 40, as well as the increased RSFC between the right culmen and right declive, indicating changes due to TLNS treatment. However, there were no correlations between the sensory/somatomotor (or visual or cerebellar) network and SOT/DGI behavioral performance.

CONCLUSIONS

Although the limited sample size may have led to lack of significant correlations with functional assessments, these results provide preliminary evidence that TLNS in conjunction with physical therapy can induce brain plasticity in TBI patients with balance and movement deficits.

Wearable Technologies Using Peripheral Neuromodulation to Enhance Mobility and Gait Function in Older Adults - A Narrative Review

BACKGROUND

Mounting evidence suggests that wearable technologies using peripheral neuromodulation can provide novel ways of improving mobility and gait function in various patient populations including older adults. The purpose of this narrative review is to provide an overview of wearable technologies/devices to improve mobility and gait function through noninvasive peripheral neuromodulation in older adults over the age of 65 and to indicate the suggested mechanism of action behind these technologies.

METHODS

We performed searches for articles and conference abstracts written in English, using the following databases: Embase Classic+Embase from 1947 to July 15, 2021; Ovid MEDLINE®; Epub Ahead of Print, In-Process, In-Data-Review & Other Non-Indexed Citations, Daily and Versions® from 1946 to July 15, 2021; PubMed; and Scopus.

RESULTS

Forty-one technologies met the inclusion/exclusion criteria. We found that the primary implementation of the 41 technologies can be divided into three main categories: sensory substitution, sensory augmentation (open loop, closed loop), and motor stimulation. Using these technologies, various aspects of mobility are treated or addressed, including e.g., gait function, fall risk, foot drop, navigating environment, postural control.

CONCLUSIONS

This narrative review summarizes wearable technologies that are currently commercially available and in stages of research and development. Overall, studies suggest that wearable peripheral neuromodulation technologies can improve aspects of mobility for older adults. Existing literature suggests that these technologies may lead to physiological changes in the brain through sensory re-weighting or other neuroplastic mechanisms to enhance the performance of mobility and gait function in older adults over the age of 65.

The role of electrical stimulation for rehabilitation and regeneration after spinal cord injury

Electrical stimulation is used to elicit muscle contraction and can be utilized for neurorehabilitation following spinal cord injury when paired with voluntary motor training. This technology is now an important therapeutic intervention that results in improvement in motor function in patients with spinal cord injuries. The purpose of this review is to summarize the various forms of electrical stimulation technology that exist and their applications. Furthermore, this paper addresses the potential future of the technology.

Cranial Nerve Noninvasive Neuromodulation in Adults With Neurological Conditions: Protocol for a Scoping Review

BACKGROUND

Cranial nerve noninvasive neuromodulation (CN-NINM) via translingual nerve stimulation (TLNS) is a promising new intervention combined with neurological rehabilitation to improve outcomes for persons with neurological conditions. A portable neuromodulation stimulation (PoNS) device rests on the tongue and stimulates cranial nerves V and VII (trigeminal and facial nerves, respectively). Emerging evidence suggests that CN-NINM using the PoNS device, combined with targeted physical therapy, improves balance and gait outcomes but has not yet been comprehensively reviewed.

OBJECTIVE

This review will describe CN-NINM via TLNS and its applications, effects, and implications for rehabilitation science in adult populations with neurological conditions. We will identify how CN-NINM via TLNS is currently being incorporated into neurological rehabilitation and identify gaps in evidence with respect to this novel technology.

METHODS

Joanna Briggs Institute methodology will be used to conduct this scoping review. Electronic databases MEDLINE, AMED, CINAHL, Embase, and Web of Science will be searched, as well as gray literature databases ProQuest, DuckDuckGo, and Google. Studies published in English and French between 2000 and 2021 will be included. Two reviewers will independently screen all titles and abstracts and full-text papers that meet the inclusion criteria. Data will be extracted and collated in a table to synthesize the results. Extracted data will be reported in a comprehensive summary.

RESULTS

The final manuscript is intended for submission to an indexed journal in September 2021.

CONCLUSIONS

This scoping review will be the first, to our knowledge, to address the current evidence on CN-NINM. The results will inform the use of CN-NINM in neurological rehabilitation and the development of recommendations for future research.

TRIAL REGISTRATION

Open Science Framework 10.17605/OSF.IO/XZQFM; https://osf.io/xzqfm.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/29965.

An updated brief overview on post-traumatic headache and a systematic review of the non-pharmacological interventions for its management

INTRODUCTION

Post-traumatic headache (PTH), a common type of headache secondary to traumatic brain injury (TBI) or whiplash, carries a relevant burden on patients. PTH is still an undertreated condition because of limited pharmacological treatment options. Therefore, multimodal non-pharmacologic approaches, which account for comorbidities and biopsychosocial factors, are often used in PTH patients.

AREAS COVERED

After providing a brief overview of PTH, a systematic review was conducted, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations on recently published (2015-2020) papers on non-pharmacological interventions for PTH. We also collected data on ongoing trials on this topic. Studies and results are reviewed and discussed.

EXPERT OPINION

PTH is one of the most common complications of TBI and accounts for almost 4% of symptomatic headache disorders. The most common clinical presentations of PTH are migraine-like or tension type (TTH)-like headache, neck pain, cognitive complaints, and psychological/psychiatric symptoms. Growing evidence suggests that combined pharmacological and non-pharmacological interventions, encompassing noninvasive neuromodulation, physical therapy, cognitive-behavioral treatment, and education, may be the best approaches for PTH and related comorbidities. Acute/preemptive pharmacological treatments for PTH include drugs used for migraine and TTH. When PTH management is multidisciplinary, the patient benefits most.

Portable neuromodulation induces neuroplasticity to re-activate motor function recovery from brain injury: a high-density MEG case study

BACKGROUND

In a recent high-profile case study, we used functional magnetic resonance imaging (fMRI) to monitor improvements in motor function related to neuroplasticity following rehabilitation for severe traumatic brain injury (TBI). The findings demonstrated that motor function improvements can occur years beyond current established limits. The current study extends the functional imaging investigation to characterize neuromodulation effects on neuroplasticity to further push the limits.

METHODS

Canadian Soldier Captain (retired) Trevor Greene (TG) survived a severe open-TBI when attacked with an axe during a 2006 combat tour in Afghanistan. TG has since continued intensive daily rehabilitation to recover motor function, experiencing an extended plateau using conventional physical therapy. To overcome this plateau, we paired translingual neurostimulation (TLNS) with the continuing rehabilitation program.

RESULTS

Combining TLNS with rehabilitation resulted in demonstrable clinical improvements along with corresponding changes in movement evoked electro-encephalography (EEG) activity. High-density magneto-encephalography (MEG) characterized cortical activation changes in corresponding beta frequency range (27 Hz). MEG activation changes corresponded with reduced interhemispheric inhibition in the post-central gyri regions together with increased right superior/middle frontal activation suggesting large scale network level changes.

CONCLUSIONS

The findings provide valuable insight into the potential importance of non-invasive neuromodulation to enhance neuroplasticity mechanisms for recovery beyond the perceived limits of rehabilitation.

The Effects of a Wearable Sensory Prosthesis on Gait and Balance Function After 10 Weeks of Use in Persons With Peripheral Neuropathy and High Fall Risk - The walk2Wellness Trial

BACKGROUND

Sensory peripheral neuropathy (PN) is associated with gait, balance problems and high fall risk. The walk2Wellness trial investigates effects of long-term, home-based daily use of a wearable sensory prosthesis on gait function, balance, quality of life and fall rates in PN patients. The device (Walkasins®, RxFunction Inc., MN, United States) partially substitutes lost nerve function related to plantar sensation providing directional tactile cues reflecting plantar pressure measurements during standing and walking. We tested the null hypothesis that the Functional Gait Assessment (FGA) score would remain unchanged after 10 weeks of use.

METHODS

Participants had PN with lost plantar sensation, gait and balance problems, an FGA score < 23 (high fall risk), and ability to sense tactile stimuli above the ankle. Clinical outcomes included FGA, Gait Speed, Timed Up&Go (TUG) and 4-Stage Balance Test. Patient-reported outcomes included Activities-Specific Balance Confidence (ABC) scale, Vestibular Disorders Activities of Daily Living Scale, PROMIS participation and satisfaction scores, pain rating, and falls. Evaluations were performed at baseline and after 2, 6, and 10 weeks. Subjects were not made aware of changes in outcomes. No additional balance interventions were allowed.

RESULTS

Forty-five participants of 52 enrolled across four sites completed in-clinic assessments. FGA scores improved from 15.0 to 19.1 (p < 0.0001), normal and fast gait speed from 0.86 m/s to 0.95 m/s (p < 0.0001) and 1.24 m/s to 1.33 m/s (p = 0.002), respectively, and TUG from 13.8 s to 12.5 s (p = 0.012). Four-Stage Balance Test did not improve. Several patient-reported outcomes were normal at baseline and remained largely unchanged. Interestingly, subjects with baseline ABC scores lower than 67% (high fall risk cut-off) increased their ABC scores (49.9% to 59.3%, p = 0.01), whereas subjects with ABC scores above 67% showed a decrease (76.6% to 71.8%, p = 0.019). Subjects who reported falls in the prior 6 months (n = 25) showed a decrease in the number of fall-risk factors (5.1 to 4.3, p = 0.023) and a decrease in fall rate (13.8 to 7.4 falls/1000 days, p = 0.014). Four pre-study non-fallers (n = 20) fell during the 10 weeks.

CONCLUSION

A wearable sensory prosthesis presents a new way to treat gait and balance problems and manage falls in high fall-risk patients with PN.

TRIAL REGISTRATION

ClinicalTrials.gov (#NCT03538756).

Brain Vital Signs Detect Information Processing Differences When Neuromodulation Is Used During Cognitive Skills Training

Background: Neuromodulation through translingual neurostimulation (TLNS) has been shown to initiate long-lasting processes of neuronal reorganization with a variety of outcomes (i.e., neuroplasticity). Non-invasive TLNS is increasingly accessible through the Portable Neuromodulation Stimulator (PoNS^®), a medical device that delivers electrical stimulation to the tongue to activate the trigeminal (V) and facial (VII) cranial nerves. Anecdotal reports from previous clinical studies have suggested incidental improvements in cognitive function. To objectively explore this observation, we examined TLNS-related effects on the semantic N400 brain vital sign cognitive response during cognitive skills training in healthy individuals. Methods: Thirty-seven healthy volunteers were randomized to receive simultaneous TLNS (treatment) or no TLNS (control) while undergoing cognitive skills training. Cognitive training was conducted for two 20-min sessions (morning and afternoon/evening) over 3 consecutive days. Brain vital signs were evaluated at baseline, Day 1, and Day 3. Analyses focused on cognitive processing as measured by N400 changes in amplitude and latency. Results: Over the 3-day course of cognitive training, the N400 amplitude decreased significantly in the control group due to habituation (p = 0.028). In contrast, there was no significant change in the TLNS treatment group. Conclusion: TLNS led to a sustained N400 response during cognitive skills training, as measured by the brain's vital signs framework. The study findings suggest differential learning effects due to neuromodulation, consistent with increased attention and cognitive vigilance.

Brain Vital Signs Detect Cognitive Improvements During Combined Physical Therapy and Neuromodulation in Rehabilitation From Severe Traumatic Brain Injury: A Case Report

Using a longitudinal case study design, we have tracked the recovery of motor function following severe traumatic brain injury (TBI) through a multimodal neuroimaging approach. In 2006, Canadian Soldier Captain (retired) Trevor Greene (TG) was attacked with an axe to the head while on tour in Afghanistan. TG continues intensive daily rehabilitation, which recently included the integration of physical therapy (PT) with neuromodulation using translingual neurostimulation (TLNS) to facilitate neuroplasticity. Recent findings with PT + TLNS demonstrated that recovery of motor function occurred beyond conventional time limits, currently extending past 14-years post-injury. To investigate whether PT + TLNS similarly resulted in associated cognitive function improvements, we examined event-related potentials (ERPs) with the brain vital signs framework. In parallel with motor function improvements, brain vital signs detected significant increases in basic attention (as measured by P300 response amplitude) and cognitive processing (as measured by contextual N400 response amplitude). These objective cognitive improvements corresponded with TG's self-reported improvements, including a noteworthy and consistent reduction in ongoing symptoms of post-traumatic stress disorder (PTSD). The findings provide valuable insight into the potential importance of non-invasive neuromodulation in cognitive rehabilitation, in addition to initial indications for physical rehabilitation.

A Review of the Evidence and Current Applications of Portable Translingual Neurostimulation Technology

OBJECTIVES

Translingual neurostimulation (TLNS) with adjunct physical rehabilitation is used to treat balance and gait deficits in several chronic neurological conditions. The purpose of this review is to summarize and appraise the evidence currently available on the portable TLNS device and to assess its potential clinical application.

MATERIALS AND METHODS

In this narrative review, MEDLINE, EMBASE, Web of Science, and Google Scholar were searched for primary research investigating the use of portable TLNS devices on any neurologic condition. Data were extracted, reviewed, and appraised with respect to study design, conduct, and reporting.

RESULTS

Five randomized controlled trials (RCTs), three quasi-experimental trials, and seven case reports/series were found. Most studies demonstrated improvements in balance and gait deficits secondary to traumatic brain injury and multiple sclerosis, but evidence is also present to a lesser degree for stroke and balance disorder patients. In these studies, the feasibility and safety of TLNS have been convincingly demonstrated. Functional magnetic resonance studies have also suggested a plausible neuroplastic therapeutic mechanism. However, the efficacy of TLNS remains unclear due to bias and confounding within studies, and heterogeneity of results between studies.

CONCLUSIONS

TLNS is a promising treatment modality for various chronic neurological conditions that are often refractory to conventional therapy. However, TLNS technology remains largely investigational as high-quality RCTs are still required to elucidate efficacy, optimal dosages, necessary treatment durations, and treatment durability. Further research to develop an appropriate control group is needed for scientifically valid comparisons of TLNS.