Feasibility of sensory tongue stimulation combined with task-specific therapy in people with spinal cord injury: a case study

Central effects of trigeminal electrical stimulation

This is a review of the literature on the main neuromodulation techniques, focusing on the possibility of introducing sensory threshold ULFTENS into them. Electro neuromodulation techniques have been in use for many years as promising methods of therapy for cognitive and emotional disorders. One of the most widely used forms of stimulation for orofacial pain is transcutaneous trigeminal stimulation on three levels: supraorbital area, dorsal surface of the tongue, and anterior skin area of the tragus. The purpose of this review is to trigger interest on using dental ULFTENS as an additional trigeminal neurostimulation and neuromodulation technique in the context of TMD. In particular, we point out the possibility of using ULFTENS at a lower activation level than that required to trigger a muscle contraction that is capable of triggering effects at the level of the autonomic nervous system, with extreme ease of execution and few side effects.

Motor and autonomic concomitant health improvements with neuromodulation and exercise (MACHINE) training: a randomised controlled trial in individuals with spinal cord injury

INTRODUCTION

Motor and autonomic dysfunctions are widespread among people with spinal cord injury (SCI), leading to poor health and reduced quality of life. Exercise interventions, such as locomotor training (LT), can promote sensorimotor and autonomic recovery post SCI. Recently, breakthroughs in SCI research have reported beneficial effects of electrical spinal cord stimulation (SCS) on motor and autonomic functions. Despite literature supporting the independent benefits of transcutaneous SCS (TSCS) and LT, the effect of pairing TSCS with LT is unknown. These therapies are non-invasive, customisable and have the potential to simultaneously benefit both sensorimotor and autonomic functions. The aim of this study is to assess the effects of LT paired with TSCS in people with chronic SCI on outcomes of sensorimotor and autonomic function.

METHODS AND ANALYSIS

Twelve eligible participants with chronic (>1 year) motor-complete SCI, at or above the sixth thoracic segment, will be enrolled in this single-blinded, randomised sham-controlled trial. Participants will undergo mapping for optimisation of stimulation parameters and baseline assessments of motor and autonomic functions. Participants will then be randomly assigned to either LT+TSCS or LT+Sham stimulation for 12 weeks, after which postintervention assessments will be performed to determine the effect of TSCS on motor and autonomic functions. The primary outcome of interest is attempted voluntary muscle activation using surface electromyography. The secondary outcomes relate to sensorimotor function, cardiovascular function, pelvic organ function and health-related quality of life. Statistical analysis will be performed using two-way repeated measures Analysis of variance (ANOVAs) or Kruskal-Wallis and Cohen's effect sizes.

ETHICS AND DISSEMINATION

This study has been approved after full ethical review by the University of British Columbia's Research Ethics Board. The stimulator used in this trial has received Investigation Testing Authorisation from Health Canada. Trial results will be disseminated through peer-reviewed publications, conference presentations and seminars.

TRIAL REGISTRATION NUMBER

NCT04726059.

Trigeminal electrical stimulation with ULFTENS of the dorsal anterior mucosal surface of the tongue: Effects on Heart Rate Variability (HRV)

BACKGROUND

Trigeminal electrical stimulation of the dorsal anterior mucosal surface of the tongue has demonstrated its efficacy in a variety of neurological disorders in which anatomical or functional alterations are present. The pathogenesis of such disorders is often linked to altered arousal circuits, and the benefits of tongue stimulation are attributed to the rebalancing of this system. Dental ULFTENS shows efficacy in acting on the muscular, autonomic system and control of the descending pathways that modulate pain. It is administered at the skin level in the area anterior to the tragus and not on the mucosal surface of the tongue. The use of this stimulation technique at the tongue level could have new applications and clinical results if it were able to reduce the activity of arousal circuits.

MATERIAL AND METHOD

A new intraoral device allowed electrical stimulation of the dorsal anterior mucosa of the tongue in 32 healthy young women. The effects on HRV were monitored by photoplethysmographic wave (PPG) and compared with a control group. The HRV parameters studied were RMSSD, HF, LF, LF/HF, REC, DET.

RESULTS

The group of stimulated subjects showed a significant change in some of the HRV parameters that was maintained even in the epoch after the end of electrical stimulation. This effect can be considered as a vagal activation and a change of HRV trend. The control group of unstimulated subjects showed an opposite trend. There were no undesirable or annoying effects of stimulation.

CONCLUSION

Stimulation of the dorsal anterior (trigeminal) mucosal surface of the tongue with ULFTENS applied with an intraoral device was shown to be able to increase HRV.

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.

Advanced rehabilitation technology in orthopaedics-a narrative review

INTRODUCTION

As the demand for rehabilitation in orthopaedics increases, so too has the development in advanced rehabilitation technology. However, to date, there are no review papers outlining the broad scope of advanced rehabilitation technology used within the orthopaedic population. The aim of this study is to identify, describe and summarise the evidence for efficacy for all advanced rehabilitation technologies applicable to orthopaedic practice.

METHODS

The relevant literature describing the use of advanced rehabilitation technology in orthopaedics was identified from appropriate electronic databases (PubMed and EMBASE) and a narrative review undertaken.

RESULTS

Advanced rehabilitation technologies were classified into two groups: hospital-based and home-based rehabilitation. In the hospital-based technology group, we describe the use of continuous passive motion and robotic devices (after spinal cord injury) and their effect on improving clinical outcomes. We also report on the use of electromagnetic sensor technology for measuring kinematics of upper and lower limbs during rehabilitation. In the home-based technology group, we describe the use of inertial sensors, smartphones, software applications and commercial game hardware that are relatively inexpensive, user-friendly and widely available. We outline the evidence for videoconferencing for promoting knowledge and motivation for rehabilitation as well as the emerging role of virtual reality.

CONCLUSIONS

The use of advanced rehabilitation technology in orthopaedics is promising and evidence for its efficacy is generally supportive.

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.

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.

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

Objectives

Materials and Methods

Results

Conclusions

Sensory Neuromodulation

We describe a model of neurological disease based on dysfunctional brain oscillators. This is not a new model, but it is not one that is widely appreciated by clinicians. The value of this model lies in the predictions it makes and the utility it provides in translational applications, in particular for neuromodulation devices. Specifically, we provide a perspective on devices that provide input to sensory receptors and thus stimulate endogenous sensory networks. Current forms of clinically applied neuromodulation, including devices such as (implanted) deep brain stimulators (DBS) and various, noninvasive methods such as transcranial magnetic stimulation (TMS) and transcranial current methods (tACS, tDCS), have been studied extensively. The potential strength of neuromodulation of a sensory organ is access to the same pathways that natural environmental stimuli use and, importantly, the modulatory signal will be transformed as it travels through the brain, allowing the modulation input to be consistent with regional neuronal dynamics. We present specific examples of devices that rely on sensory neuromodulation and evaluate the translational potential of these approaches. We argue that sensory neuromodulation is well suited to, ideally, repair dysfunctional brain oscillators, thus providing a broad therapeutic approach for neurological diseases.

Translingual Neurostimulation for the Treatment of Chronic Symptoms Due to Mild-to-Moderate Traumatic Brain Injury

Objective

To compare the efficacy of high- and low-frequency noninvasive translingual neurostimulation (TLNS) plus targeted physical therapy (PT) for treating chronic balance and gait deficits due to mild-to-moderate traumatic brain injury (mmTBI).

Design

Participants were randomized 1:1 in a 26-week double-blind phase 1/2 study (NCT02158494) with 3 consecutive treatment stages: in-clinic, at-home, and no treatment. Arms were high-frequency pulse (HFP) and low-frequency pulse (LFP) TLNS.

Setting

TLNS plus PT training was initiated in-clinic and then continued at home.

Participants

Participants (N=44; 18-65y) from across the United States were randomized into the HFP and LFP (each plus PT) arms. Forty-three participants (28 women, 15 men) completed at least 1 stage of the study. Enrollment requirements included an mmTBI ≥1 year prior to screening, balance disorder due to mmTBI, a plateau in recovery with current PT, and a Sensory Organization Test (SOT) score ≥16 points below normal.

Interventions

Participants received TLNS (HFP or LFP) plus PT for a total of 14 weeks (2 in-clinic and 12 at home), twice daily, followed by 12 weeks without treatment.

Main Outcome Measures

The primary endpoint was change in SOT composite score from baseline to week 14. Secondary variables (eg, Dynamic Gait Index [DGI], 6-minute walk test [6MWT]) were also collected.

Results

Both arms had a significant (P<.0001) improvement in SOT scores from baseline at weeks 2, 5, 14 (primary endpoint), and 26. DGI scores had significant improvement (P<.001-.01) from baseline at the same test points; 6MWT evaluations after 2 weeks were significant. The SOT, DGI, and 6MWT scores did not significantly differ between arms at any test point. There were no treatment-related serious adverse events.

Conclusions

Both the HFP+PT and LFP+PT groups had significantly improved balance scores, and outcomes were sustained for 12 weeks after discontinuing TLNS treatment. Results between arms did not significantly differ from each other. Whether the 2 dosages are equally effective or whether improvements are because of provision of PT cannot be conclusively established at this time.

Citrus fruits induced swallow syncope with atrioventricular block or sinus arrest

Swallow syncope is a relatively rare syndrome and caused by various foods and drinks. A 76-year-old man was admitted with frequent syncope while eating. Holter electrocardiogram revealed frequent occurrence of atrioventricular block during meals. Both atrioventricular block and sinus arrest were induced by only eating citrus fruits, citrus jelly, and acidic foods but not by other drinks and foods. These arrhythmias were suppressed after administration of atropine. No further episodes of syncope recurred after the implantation of a DDD pacemaker. This case indicated that acidic stimulation of citrus induced a vasovagal reflex via esophageal nociceptors leading to syncope.

Current state of balance assessment during transferring, sitting, standing and walking activities for the spinal cord injured population: A systematic review

CONTEXT

Comprehensive balance measures with high clinical utility and sound psychometric properties are needed to inform the rehabilitation of individuals with spinal cord injury (SCI).

OBJECTIVE

To identify the balance measures used in the SCI population, and to evaluate their clinical utility, psychometric properties and comprehensiveness.

METHODS

Medline, PubMed, Embase, Scopus, Web of Science, and the Allied and Complementary Medicine Database were searched from the earliest record to October 19/16. Two researchers independently screened abstracts for articles including a balance measure and adults with SCI. Extracted data included participant characteristics and descriptions of balance measures. Quality was evaluated by considering study design, sampling method and adequacy of description of research participants. Clinical utility of all balance measures was evaluated. Comprehensiveness was evaluated using the modified Systems Framework for Postural Control.

RESULTS

2820 abstracts were returned and 127 articles included. Thirty-one balance measures were identified; 11 evaluated a biomechanical construct and 20 were balance scales. All balance scales had high clinical utility. The Berg Balance Scale and Functional Reach Test were valid and reliable, while the mini-BESTest was the most comprehensive.

CONCLUSION

No single measure had high clinical utility, strong psychometric properties and comprehensiveness. The mini-BESTest and/or Activity-based Balance Level Evaluation may fill this gap with further testing of their psychometric properties.

Robotic assisted gait as a tool for rehabilitation of individuals with spinal cord injury: a systematic review

BACKGROUND

Spinal cord injury (SCI) is characterized by a total or partial deficit of sensory and motor pathways. Impairments of this injury compromise muscle recruitment and motor planning, thus reducing functional capacity. SCI patients commonly present psychological, intestinal, urinary, osteomioarticular, tegumentary, cardiorespiratory and neural alterations that aggravate in chronic phase. One of the neurorehabilitation goals is the restoration of these abilities by favoring improvement in the quality of life and functional independence. Current literature highlights several benefits of robotic gait therapies in SCI individuals.

OBJECTIVES

The purpose of this study was to compare the robotic gait devices, and systematize the scientific evidences of these devices as a tool for rehabilitation of SCI individuals.

METHODS

A systematic review was carried out in which relevant articles were identified by searching the following databases: Cochrane Library, PubMed, PEDro and Capes Periodic. Two authors selected the articles which used a robotic device for rehabilitation of spinal cord injury.

RESULTS

Databases search found 2941 articles, 39 articles were included due to meet the inclusion criteria. The robotic devices presented distinct features, with increasing application in the last years. Studies have shown promising results regarding the reduction of pain perception and spasticity level; alteration of the proprioceptive capacity, sensitivity to temperature, vibration, pressure, reflex behavior, electrical activity at muscular and cortical level, classification of the injury level; increase in walking speed, step length and distance traveled; improvements in sitting posture, intestinal, cardiorespiratory, metabolic, tegmental and psychological functions.

CONCLUSIONS

This systematic review shows a significant progress encompassing robotic devices as an innovative and effective therapy for the rehabilitation of individuals with SCI.

Exercise Training Promotes Functional Recovery after Spinal Cord Injury

The exercise training is an effective therapy for spinal cord injury which has been applied to clinic. Traditionally, the exercise training has been considered to improve spinal cord function only through enhancement, compensation, and replacement of the remaining function of nerve and muscle. Recently, accumulating evidences indicated that exercise training can improve the function in different levels from end-effector organ such as skeletal muscle to cerebral cortex through reshaping skeletal muscle structure and muscle fiber type, regulating physiological and metabolic function of motor neurons in the spinal cord and remodeling function of the cerebral cortex. We compiled published data collected in different animal models and clinical studies into a succinct review of the current state of knowledge.