Dizziness after traumatic brain injury: Overview and measurement in the clinical setting

Balance recovery and its link to vestibular agnosia in traumatic brain injury: a longitudinal behavioural and neuro-imaging study

BACKGROUND

Vestibular dysfunction causing imbalance affects c. 80% of acute hospitalized traumatic brain injury (TBI) cases. Poor balance recovery is linked to worse return-to-work rates and reduced longevity. We previously showed that white matter network disruption, particularly of right inferior longitudinal fasciculus, mediates the overlap between imbalance and impaired vestibular perception of self-motion (i.e., vestibular agnosia) in acute hospitalized TBI. However, there are no prior reports tracking the acute-longitudinal trajectory of objectively measured vestibular function for hospitalized TBI patients. We hypothesized that recovery of vestibular agnosia and imbalance is linked and mediated by overlapping brain networks.

METHODS

We screened 918 acute major trauma in-patients, assessed 146, recruited 39 acutely, and retested 34 at 6 months. Inclusion criteria were 18-65-year-old adults hospitalized for TBI with laboratory-confirmed preserved peripheral vestibular function. Benign paroxysmal positional vertigo and migraine were treated prior to testing. Vestibular agnosia was quantified by participants' ability to perceive whole-body yaw plane rotations via an automated rotating-chair algorithm. Subjective symptoms of imbalance (via questionnaires) and objective imbalance (via posturography) were also assessed.

RESULTS

Acute vestibular agnosia predicted poor balance recovery at 6 months. Recovery of vestibular agnosia and linked imbalance was mediated by bihemispheric fronto-posterior cortical circuits. Recovery of subjective symptoms of imbalance and objective imbalance were not correlated.

CONCLUSION

Vestibular agnosia mediates balance recovery post-TBI. The link between subjective dizziness and brain injury recovery, although important, is unclear. Therapeutic trials of vestibular recovery post-TBI should target enhancing bi-hemispheric connectivity and linked objective clinical measures (e.g., posturography).

Evidence of Peripheral Vestibular Impairment Among Adults With Chronic Moderate-Severe Traumatic Brain Injury

PURPOSE

Traumatic brain injury (TBI) is a leading cause of death and disability among adults in the United States. There is evidence to suggest the peripheral vestibular system is vulnerable to damage in individuals with TBI. However, there are limited prospective studies that describe the type and frequency of vestibular impairment in individuals with chronic moderate-severe TBI (> 6 months postinjury).

METHOD

Cervical and ocular vestibular evoked myogenic potentials (VEMPs) and video head impulse test (vHIT) were used to assess the function of otolith organ and horizontal semicircular canal (hSCC) pathways in adults with chronic moderate-severe TBI and in noninjured comparison (NC) participants. Self-report questionnaires were administered to participants with TBI to determine prevalence of vestibular symptoms and quality of life associated with those symptoms.

RESULTS

Chronic moderate-severe TBI was associated with a greater degree of impairment in otolith organ, rather than hSCC, pathways. About 63% of participants with TBI had abnormal VEMP responses, compared to only ~10% with abnormal vHIT responses. The NC group had significantly less abnormal VEMP responses (~7%), while none of the NC participants had abnormal vHIT responses. As many as 80% of participants with TBI reported vestibular symptoms, and up to 36% reported that these symptoms negatively affected their quality of life.

CONCLUSIONS

Adults with TBI reported vestibular symptoms and decreased quality of life related to those symptoms and had objective evidence of peripheral vestibular impairment. Vestibular testing for adults with chronic TBI who report persistent dizziness and imbalance may serve as a guide for treatment and rehabilitation in these individuals.

Cardiorespiratory fitness assessment and training in the early sub-acute phase of recovery following traumatic brain injury: a systematic review

OBJECTIVES

To examine the safety of cardiorespiratory fitness (CRF) assessment and training in the early sub-acute phase of recovery (≤3 months) following moderate-to-extremely severe traumatic brain injury (TBI).

METHODS

A systematic review was completed in accordance with the PRISMA guidelines. Studies investigating adults and adolescents ≥15 years with moderate-to-extremely severe TBI were considered for inclusion. The methodological quality of the included studies was evaluated according to the McMaster Guidelines for Critical Review Form - Quantitative Studies.

RESULTS

Eleven studies with a total of 380 participants were included in the review. Adverse events (AEs) and symptom monitoring were poorly reported. Only four studies reported on the occurrence of AEs, with a total of eight AEs reported. Three of the reported AEs were concussion-like symptoms with no further exercise-induced symptom exacerbation reported. No serious AEs were reported.

CONCLUSION

There is no evidence to suggest that CRF assessment and training is unsafe in the early sub-acute phase of recovery following moderate-to-extremely severe TBI. However, despite the low AE and symptom exacerbation rates identified, a timeframe for safe commencement was unable to be established due to poor reporting and/or monitoring of exercise-induced symptoms and AEs in the current literature.

Auditory Dysfunction After Head Trauma: Causes, Evaluation, and Treatment

Purpose of Review

Hearing loss after traumatic brain injury is common but often overlooked. This article reviews the etiology, pathophysiology, treatment methods, and outcomes for patients with hearing loss after traumatic brain injury.

Recent Findings

Common symptoms after TBI include hearing loss, tinnitus, hyperacusis, and dizziness. Recent literature has shown that debilitating auditory dysfunction can manifest even after mild head trauma.

Summary

There is a wide range of otologic pathologies that can occur after head trauma. All etiologies can lead to auditory dysfunction which in some cases may be permanent.

Community Reintegration After Traumatic Brain Injury

Achieving effective community reintegration is important to maximize recovery in patients with traumatic brain injury, simultaneously limiting caregiver burden and improving satisfaction with quality of life. Certain medical complications that are common after brain injury may impact community reintegration, and should be addressed by the physician in a systematic approach. Additionally certain social and environmental factors such as mobility or return to work or school may arise, and should be addressed proactively by the physician. Inpatient/residential or outpatient programs with case management and a multi-disciplinary team can facilitate community reentry for patients, and should be considered when available.

Concussion can increase the risk of visually induced motion sickness

Concussion can lead to various symptoms such as balance problems, memory impairments, dizziness, and/or headaches. It has been previously suggested that during self-motion relevant tasks, individuals with concussion may rely heavily on visual information to compensate for potentially less reliable vestibular inputs and/or problems with multisensory integration. As such, concussed individuals may also be more sensitive to other visually-driven sensations such as visually induced motion sickness (VIMS). To investigate whether concussed individuals are at elevated risk of experiencing VIMS, we exposed participants with concussion (n = 16) and healthy controls (n = 15) to a virtual scene depicting visual self-motion down a grocery store aisle at different speeds. Participants with concussion were further separated into symptomatic and asymptomatic groups. VIMS was measured with the SSQ before and after stimulus exposure, and visual dependence, self-reported dizziness, and somatization were recorded at baseline. Results showed that concussed participants who were symptomatic demonstrated significantly higher SSQ scores after stimulus presentation compared to healthy controls and those who were asymptomatic. Visual dependence was positively correlated with the level of VIMS in healthy controls and participants with concussion. Our results suggest that the presence of concussion symptoms at time of testing significantly increased the risk and severity of VIMS. This finding is of relevance with regards to the use of visual display devices such as Virtual Reality applications in the assessment and rehabilitation of individuals with concussion.

Overview of Treatment Options for Mild Traumatic Brain Injury: A Literature Review

The incidence and prevalence of concussion, a type of mild traumatic brain injury (mTBI), have steadily increased among athletes, both students and professionals, across a wide variety of sports, including, but not limited to, swimming, tennis, football, and boxing. Recent data have demonstrated that sports are one of the leading causes of concussions among student athletes. While the exact mechanism of concussion onset has yet to be fully elucidated, data suggest that the pathophysiology involves rotational acceleration and deceleration of the brain, leading to axon tearing and disturbance in the metabolic cascade of glucose. Concussive events can have debilitating effects on an athlete, including chronic traumatic encephalopathy (gradual degeneration of brain tissue) that is related to personality changes, emotional disorders, and even dementia. Common symptoms associated with concussion include dizziness, nausea, vomiting, and headaches. The physical assessment consists of a combination of tools involving the mental status examination, vital signs, cervical spine exam, eye exam, and neurological testing. The use of osteopathic manipulative medicine (OMM), pharmacotherapy, hyperbaric oxygen therapy (HBOT), aerobic exercise, balance, and/or vestibular therapy are many common treatment approaches for concussion and post-concussion sequelae. This literature review aims to provide insight into concussions, the current treatment options available, and the new developments in concussions per the Amsterdam 2022 International Consensus Statement on Concussion in Sport published in 2023.

The Efficacy of Vestibular Rehabilitation Therapy for Mild Traumatic Brain Injury: A Systematic Review and Meta-analysis

OBJECTIVE

Mild traumatic brain injury (mTBI) or concussion is a common yet undermanaged and underreported condition. This systematic review and meta-analysis aim to determine the efficacy of vestibular rehabilitation therapy (VRT) as a treatment option for mTBI.

METHOD

This review and meta-analysis was performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. It included randomized controlled trials and pre-VRT/post-VRT retrospective chart reviews. Records meeting the inclusion criteria were extracted from the following databases: MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL).

RESULTS

Eight articles met the inclusion criteria, from which 6 randomized controlled trials were included in the meta-analysis. VRT demonstrated significant improvement in decreasing perceived dizziness at the end of the intervention program as shown by Dizziness Handicap Inventory (DHI) scores (standardized mean difference [SMD] = -0.33, 95% confidence interval [CI]: -0.62 to -0.03, P = .03, I2 = 0%). However, no significant reduction in DHI was evident after 2 months of follow-up (SMD = 0.15, 95% CI: -0.23 to 0.52, P = .44, I2 = 0%). Quantitative analysis also depicted significant reduction in both Vestibular/Ocular Motor Screening (SMD = -0.40, 95% CI: -0.60 to -0.20, P < .0001, I2 = 0%) and Post-Concussion Symptom Scale (SMD= -0.39, 95% CI: -0.71 to -0.07, P = .02, I2 = 0%) following the intervention. Finally, there was no significant difference between intervention groups on Balance Error Scoring System scores (SMD = -31, 95% CI: -0.71 to 0.10, P = .14, I2 = 0%) and return to sport/function (95% CI: 0.32-30.80, P = .32, I2 = 82%).

CONCLUSIONS

Current evidence on the efficacy of VRT for mTBI is limited. This review and analysis provides evidence that supports the role of VRT in improving perceived symptoms following concussion. Although findings from this analysis suggest positive effects of VRT on included outcomes, the low certainty of evidence limits the conclusions drawn from this study. There is still a need for high-quality trials evaluating the benefit of VRT using a standardized approach.PROSPERO registration number: CRD42022342473.

Assessing the Effects of Mild Traumatic Brain Injury on Vestibular Home Exercise Performance with Wearable Sensors

After a mild traumatic brain injury (mTBI), dizziness and balance problems are frequently reported, affecting individuals' daily lives and functioning. Vestibular rehabilitation is a standard treatment approach for addressing these issues, but its efficacy in this population remains inconclusive. A potential reason for suboptimal outcomes is the lack of objective monitoring of exercise performance, which is crucial for therapeutic success. This study utilized wearable inertial measurement units (IMUs) to quantify exercise performance in individuals with mTBI during home-based vestibular rehabilitation exercises. Seventy-three people with mTBI and fifty healthy controls were enrolled. Vestibular exercises were performed, and IMUs measured forehead and sternum velocities and range of motions. The mTBI group demonstrated a slower forehead peak angular velocity in all exercises, which may be a compensatory strategy to manage balance issues or symptom exacerbation. Additionally, the mTBI group exhibited a larger forehead range of motion during specific exercises, potentially linked to proprioceptive deficits. These findings emphasize the usefulness of utilizing IMUs to monitor the quality of home-based vestibular exercises for individuals with mTBI and the potential for IMUs improving rehabilitation outcomes.

The effect of self-reported balance confidence on community integration after brain injury: an observational study

OBJECTIVE

To evaluate the correlation between self-reported balance confidence and community integration related to home management for community-dwelling adults with acquired brain injury (ABI).

METHODS

This is a study of 141 participants over the age of 18 with a history of ABI, living in the community, who completed an online survey. The survey included a series of demographic questions followed by the Activities-Specific Balance Confidence Scale (ABC) and the Home Integration subscale of the Community Integration Questionnaire (CIQ-H).

RESULTS

Data from 119 completed surveys were included in the analysis. Significant positive correlations were found between the ABC and the CIQ-H total scores (rs = 0.241, p = 0.008). There was no significant difference between CIQ-H total scores in individuals by injury type (traumatic vs non-traumatic) or by level of severity (mild, moderate, severe) (p > 0.05). There was no significant difference between ABC total scores by injury type (p > 0.05).

CONCLUSIONS

Higher levels of balance confidence may be associated with improved community integration related to home management for individuals with traumatic and non-traumatic BI. This study's results support future research to evaluate the integration of strategies to improve balance confidence as a component of interdisciplinary assessment and rehabilitation to maximize community integration in community-dwelling adults with ABI.

Associations between white matter integrity and postural control in adults with traumatic brain injury

Abnormalities of postural sway have been extensively reported in traumatic brain injury (TBI). However, the underlying neural correlates of balance disturbances in TBI remain to be elucidated. Studies in children with TBI have reported associations between the Sensory Organization Test (SOT) and measures of white matter (WM) integrity with diffusion tensor imaging (DTI) in brain areas responsible for multisensory integration. This study seeks to replicate those associations in adults as well as explore relationships between DTI and the Limits of Stability (LOS) Test. Fifty-six participants (43±17 years old) with a history of TBI were tested 30 days to 5 years post-TBI. This study confirmed results in children for associations between the SOT and the medial lemniscus as well as middle cerebellar peduncle, and revealed additional associations with the posterior thalamic radiation. Additionally, this study found significant correlations between abnormal LOS scores and impaired WM integrity in the cingulum, corpus callosum, corticopontine and corticospinal tracts, fronto-occipital fasciculi, longitudinal fasciculi, medial lemniscus, optic tracts and thalamic radiations. Our findings indicate the involvement of a broad range of WM tracts in the control of posture, and demonstrate the impact of TBI on balance via disruptions to WM integrity.

Self-Reported Symptoms of Vertigo and Imbalance Are Prevalent Among Adults With Chronic Moderate-Severe Traumatic Brain Injury: A Preliminary Analysis

PURPOSE

Dizziness and imbalance are common symptoms during the acute phase of traumatic brain injury (TBI). However, there is evidence to suggest that these symptoms persist into the chronic phase of injury. Few prospective studies have examined the frequency and type of dizziness and imbalance in adults with chronic moderate-severe TBI. The aim of this preliminary analysis was to investigate the prevalence of these symptoms in adults with chronic moderate-severe TBI.

METHOD

Twenty-four adults with chronic moderate-severe TBI and a group of 19 age-, sex-, and education-matched noninjured comparison participants were recruited. Self-reported dizziness and imbalance were measured using a modified version of a standard case history form. Significant associations between group (TBI group or noninjured comparison [NC] participants) and self-reports of dizziness, imbalance, and related symptoms (endorsed "yes" or "no") were explored.

RESULTS

The TBI group most reported lightheadedness (75%), vertigo (38%), and imbalance and/or falling (46%). The most common related symptom reported by the TBI group was headache (63%) and nausea (46%). Significant associations revealed that the TBI group responded "yes" in higher percentages than the NC group across all categories (dizziness, imbalance, and related symptoms). There were no statistically significant relationships among dizziness, imbalance, or headache symptoms within the TBI group.

CONCLUSIONS

These preliminary findings suggest that dizziness and imbalance are prevalent in adults with chronic moderate-severe TBI. Persistent vertiginous symptoms may point to an underlying vestibular impairment. However, further research is needed to characterize vestibular function in chronic moderate-severe TBI.

Research Letter: Rate of BPPV in Patients Diagnosed With Concussion

OBJECTIVE

The purpose of this study was to investigate the incidence of benign paroxysmal positional vertigo (BPPV) specifically among patients with dizziness in the rehabilitation phase of concussion recovery and to provide evidence regarding the importance of BPPV assessment in physical therapy concussion evaluations.

SETTING

Outpatient neurologic rehabilitation center at a suburban comprehensive rehabilitation hospital.

PARTICIPANTS

Fifty patients diagnosed with concussion and referred to vestibular physical therapy with complaints of dizziness were tested for BPPV within their first 3 visits.

DESIGN

In this prospective cohort study, a positive Dix-Hallpike test or Horizontal Roll test indicated the presence of BPPV.

MAIN MEASURES

The primary outcome measure was the presence of BPPV. Additional demographic and injury-specific variables were also considered. Among secondary outcomes, patient characteristics and Dizziness Handicap Inventory scores were compared on the basis of presence or absence of BPPV.

RESULTS

Eleven participants, 22%, tested positive for BPPV. Only fall, as the mechanism of injury, was statistically significant ( P < .05), with 72.7% of those who tested positive for BPPV reporting having been injured in a fall compared with 30.8% in the negative group. Nearly half, 45%, of the participants who were positive for BPPV had resolution of their BPPV within 1 visit.

CONCLUSION

This study is unique in its focus on mild traumatic brain injury in the rehabilitation phase of recovery. The results provide evidence regarding the importance of BPPV assessment in physical therapy concussion evaluations.

Vestibular Rehabilitation as an Early Intervention in Athletes Who are Post-concussion: A Systematic Review

Background

Sports-related concussions (SRC) are a common injury sustained by many athletes of all different age groups and sports. The current standard treatment is rest followed by aerobic activity. Minimal research has been done on the effects of vestibular rehabilitation for concussion treatment, especially in physical therapy practice.

Objective

The purpose of this study was to examine the effects of early intervention of vestibular rehabilitation (VRT) on an athlete's time to return to play compared to rest alone.

Study Design

Systematic Review.

Methods

Two searches were conducted (August 2021 and January 2022) using databases: CINAHL complete, MEDLINE, PubMed, and Wiley online database. One hand search was performed to find relevant articles. Search terms included "vestibular rehabilitation" or "vestibular therapy" and "concussion" or "mild traumatic brain injury" or "mTBI" and "athletes" or "sports" or "athletics" or "performance", and "early interventions" or "therapy" or "treatment". Inclusion criteria were athletes with a SRC, incorporation of vestibular rehabilitation in athletes' recovery, and early vestibular intervention tools. Tools used to assess quality and risk of bias were the PEDro scale and the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence. The PRISMA method for determining inclusion and exclusion criteria.

Results

Eleven articles were included, six randomized control trials and five retrospective cohort studies. Various balance interventions, visual interventions utilizing vestibulo-ocular reflex (VOR), and cervical manual therapy were used during VRT for athletes' post-concussion. Incorporating visual interventions and cervical manual therapy into early rehabilitation significantly reduced symptoms and time to return to sport. However, balance interventions did not have a significant effect on reducing time to return to sport when used as a sole intervention.

Conclusion

Addressing VRT deficits in the acute stages of a concussion may contribute to a quicker resolution of symptoms and a quicker return to sport. More research needs to be performed to determine the effectiveness of early intervention of VRT in concussion recovery.

Level of Evidence

1.

Occupational and Physiotherapy modalities used to support interdisciplinary rehabilitation after concussion: A Scoping Review

OBJECTIVE

To identify and describe occupational and physiotherapy rehabilitation modalities used to support an interdisciplinary rehabilitation in adults (aged 16 + years) with concussion.

METHODS

A scoping review methodology was used. Included studies were categorized according to Wade's elements of rehabilitation and the Danish White Paper definition of rehabilitation.

RESULTS

Ten studies were included in this review, addressing: "assessment" (n = 9), "goal-setting" (n = 4), "training" (n = 10), and "social participation and discharge support" (n = 4). Interventions were delivered mainly by physiotherapists or an interdisciplinary team. In two studies occupational therapists were part of the interdisciplinary team. Randomized controlled trials more often addressed several of the rehabilitation elements using interdisciplinary intervention delivery. No studies specifically aimed their intervention at patients with acute or subacute concussion.

CONCLUSION

The therapeutic modalities identified were: (i) manual and sensory motor interventions; (ii) physical exercises; and (iii) management of, or coping with, symptoms. More research is needed on how to better support social participation and discharge or return to work in the rehabilitation process. In addition, interventions delivered in the acute phases of concussion need further exploration.

Adults are not older adolescents: comparing physical therapy findings among adolescents, young adults and older adults with persistent post-concussive symptoms

OBJECTIVE

Individuals with persistent post-concussive symptoms (PPCS) may present with a myriad of physical symptoms. There is limited research available comparing the presence of examination findings among individuals with PPCS from different age groups.

METHODS

Retrospective case-control chart review of 481 patients with PPCS and 271 non-trauma controls. Physical assessments were categorized as ocular, cervical, and vestibular/balance. Differences in presentation were compared between PPCS and controls as well as between individuals with PPCS in three age groups: adolescents, young adults, and older adults.

RESULTS

All three PPCS groups had more abnormal oculomotor findings than their age-matched counterparts. When comparing PPCS patients from different age groups, no differences were seen in prevalence of abnormal smooth pursuits or saccades; however, adolescents with PPCS had more abnormal cervical findings and a lower prevalence of abnormal NPC, vestibular and balance findings.

CONCLUSION

Patients with PPCS presented with a different constellation of clinical findings based on their age. Adolescents were more likely to demonstrate evidence of cervical injury compared to younger and older adults, and adults were more likely to present with vestibular findings and impaired NPC. Adults with PPCS were more likely to present with abnormal oculomotor findings compared to adults with non-traumatic causes of dizziness.

Integrating Transcranial Direct Current Stimulation into an Existing Inpatient Physiotherapy Program to Enhance Motor Learning in an Adolescent with Traumatic Brain Injury: A Case Report

PURPOSE

Describe how transcranial direct current stimulation (tDCS) was incorporated into an inpatient physiotherapy program for an adolescent with severe traumatic brain injury (TBI), detail the motor learning focus of the physiotherapy sessions, and summarize gross motor progress.

METHOD

This case report describes an adolescent who received 20 minutes of anodal tDCS immediately prior to 16 physiotherapy sessions over four weeks. Potential side effects were tracked pre/post tDCS. Gross motor outcomes were measured pre-intervention, post-intervention, and three months post-intervention. Physiotherapy session content was analyzed using therapist documentation and the Motor Learning Strategies Rating Instrument.

RESULTS

The youth tolerated tDCS well. The primary side effect was itchiness under the electrodes during tDCS sessions. His mobility progressed from wheelchair use pre- 'tDCS + physiotherapy' to ambulation with a walker post-intervention. His Gross Motor Function Measure score increased 33.1% points pre/post intervention. Session tasks often had several foci (e.g., skill acquisition, strength, and balance) with task focus changing as the youth progressed. Various motor learning strategies were layered within tasks to support performance and learning.

CONCLUSIONS

tDCS was successfully integrated into an existing inpatient physiotherapy program for an adolescent with TBI. This protocol provides a structure for implementing, monitoring, and measuring tDCS + physiotherapy in pediatric rehabilitation.

Why are patients with acute traumatic brain injury not routinely assessed or treated for vestibular dysfunction in the UK? A qualitative study

OBJECTIVES

Vestibular dysfunction is common in patients with acute traumatic brain injury (aTBI). Persisting vestibular symptoms (ie, dizziness and imbalance) are linked to poor physical, psychological and socioeconomic outcomes. However, routine management of vestibular dysfunction in aTBI is not always standard practice. We aimed to identify and explore any healthcare professional barriers or facilitators to managing vestibular dysfunction in aTBI.

DESIGN

A qualitative approach was used. Data were collected using face to face, semi-structured interviews and analysed using the Framework approach.

SETTING

Two major trauma centres in London, UK.

PARTICIPANTS

28 healthcare professionals participated: 11 occupational therapists, 8 physiotherapists and 9 surgical/trauma doctors.

RESULTS

Vestibular assessment and treatment were not routinely undertaken by trauma ward staff. Uncertainty regarding responsibility for vestibular management on the trauma ward was perceived to lead to gaps in patient care. Interestingly, the term dizziness was sometimes perceived as an 'invisible' and vague phenomenon, leading to difficulties identifying or 'proving' dizziness and a tendency for making non-specific diagnoses. Barriers to routine assessment and treatment included limited knowledge and skills, a lack of local or national guidelines, insufficient training and concerns regarding the practical aspects of managing vestibular dysfunction. Of current trauma ward staff, therapists were identified as appropriate healthcare professionals to adopt new behaviours regarding management of a common form of vestibular dysfunction (benign paroxysmal positional vertigo). Strategies to support this behaviour change include heightened clarity around role, implementation of local or national guidelines, improved access to training and multidisciplinary support from experts in vestibular dysfunction.

CONCLUSIONS

This study has highlighted that role and knowledge barriers exist to multidisciplinary management of vestibular dysfunction in aTBI. Trauma ward therapists were identified as the most appropriate healthcare professionals to adopt new behaviours. Several strategies are proposed to facilitate such behaviour change.

TRIAL REGISTRATION NUMBER

ISRCTN91943864.

Dizziness After Traumatic Brain Injury: A Prospective TRACK-TBI Analysis of Risk Factors, Quality of Life, and Neurocognitive Effects

OBJECTIVE

To determine the longitudinal incidence of dizziness and its association with demographic factors, neurocognitive effects, functionality, and quality of life.

STUDY DESIGN

Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) is a prospective, longitudinal cohort study in which TBI patients were assessed at the emergency department and 2-week, 3-month, 6-month, and 12-month follow-up via telephone and/or in-person visits.

SETTING

Multicenter study in emergency departments of 18 academic medical centers in the United States.

PATIENTS

A total of 1,514 patients 17 years or older with a diagnosis of TBI, injury occurrence within 24 hours of admission, fluency in English or Spanish, and completed Rivermead Post-Concussion Symptoms Questionnaire (RPQ) at 12 months were enrolled between February 2014 and August 2018.

MAIN OUTCOME MEASURE

RPQ, Short Form-12 Version 2, Wechsler Adult Intelligence Scale IV, Trail Making Test, Patient Health Questionnaire-9, PROMIS-PAIN, and Glasgow Outcome Scale-Extended Revised. The primary outcome measure was a self-report of "feelings of dizziness" on RPQ at 12 months post-TBI.

RESULTS

Of the 1,514 participants, 1,002 (66%) were male and 512 (34%) were female. The mean age was 41.6 (SD, 17.4) years. At 12 months, 26% experienced dizziness, with 9% experiencing moderate or severe dizziness. Dizziness was strongly associated with headache (odds ratio [OR], 3.45; 95% confidence interval [CI], 2.92-4.07; p < 0.001), nausea (OR, 4.43; 95% CI, 3.45-5.69; p < 0.001), worse hearing (OR, 3.57; 95% CI, 2.64-4.82; p < 0.001), noise sensitivity (OR, 3.02; 95% CI, 2.54-3.59; p < 0.001), and light sensitivity (OR, 3.51; 95% CI, 2.91-4.23; p < 0.001). In multivariable regression models, participants with severe dizziness demonstrated lower performance compared with those without new or worse dizziness on the Wechsler Adult Intelligence Scale IV (-6.64; p < 0.001), Trail Making Test part A (7.90; p = 0.003) and part B (19.77; p = 0.028), and Short Form-12 physical (-13.60; p < 0.001) and mental health (-11.17; p < 0.001), after controlling for age, sex, education, and TBI severity.

CONCLUSION

Dizziness is common among TBI patients and relates to quality of life and neurocognitive performance.

Rationale and methodology for examining the acute effects of aerobic exercise combined with varying degrees of virtual reality immersion on cognition in persons with TBI

Persons with Traumatic Brain Injury (TBI) commonly present with long-term cognitive deficits in executive function, processing speed, attention, and learning and memory. While specific cognitive rehabilitation techniques have shown significant success for deficits in individual domains, aerobic exercise training represents a promising approach for an efficient and general treatment modality that might improve many cognitive domains concurrently. Existing studies in TBI report equivocal results, however, and are hampered by methodological concerns, including small sample sizes, uncontrolled single-group designs, and the use of suboptimal exercise modalities for eliciting cognitive improvements in this population. One particularly promising modality involves the application of environmental enrichment via virtual reality (VR) during aerobic exercise in persons with TBI, but this has yet to be investigated. One approach for systematically developing an optimal aerobic exercise intervention for persons with TBI involves the examination of single bouts of aerobic exercise (i.e., acute aerobic exercise) on cognition. Acute exercise research is a necessary first step for informing the development of high-quality exercise training interventions that are more likely to induce meaningful beneficial effects. To date, such an acute exercise paradigm has yet to be conducted in persons with TBI. To that end, we propose an acute exercise study that will investigate the acute effects of aerobic exercise with incremental degrees of environmental enrichment (VR) relative to a control comparison condition on executive function (divided attention and working memory) and processing speed in 24 people with TBI.

Visual disorders and mal de debarquement syndrome: a potential comorbidity questionnaire-based study

Aim: Mal de debarquement syndrome (MdDS) is a neurological condition characterized by a constant sensation of self-motion; onset may be motion-triggered (MT) or non-motion-triggered/spontaneous (NMT/SO). People with MdDS experience similar symptoms to those with vertical heterophoria, a subset of binocular visual dysfunction. Hence, we aimed to explore potential visual symptom overlaps. Methods: MdDS patients (n = 196) and controls (n = 197) completed a visual health questionnaire. Results: Compared with controls, the MdDS group demonstrated higher visual disorder scores and visual complaints. NMT/SO participants reported unique visual symptoms and a higher prevalence of mild traumatic brain injury. Conclusion: Our findings suggest visual disorders may coexist with MdDS, particularly the NMT/SO subtype. The difference in visual dysfunction frequency and medical histories between subtypes, warrants further investigation into differing pathophysiological mechanisms.

A Comparison of Generalized and Individualized Vestibular Rehabilitation Therapy in a Military TBI Sample

OBJECTIVE

To compare clinical outcomes between active duty service members receiving generalized versus individualized vestibular rehabilitation treatment (GVRT and IVRT, respectively) for persistent vestibular-related symptoms following mild traumatic brain injury (mTBI).

SETTING

An outpatient TBI rehabilitation clinic.

PARTICIPANTS

Fifty-seven participants with persistent vestibular-related symptoms following mTBI were randomly assigned to the GVRT (n = 28) or IVRT (n = 29) group, stratified by dizziness-related impairment severity. Forty-two participants (n = 21 per group) completed the posttreatment evaluation and were included in analyses.

DESIGN

We employed a single-site, randomized, pre-/posttest experimental design. The GVRT program consisted of eight 45-minute group-based treatment sessions and IVRT consisted of three 30-minute one-on-one treatment sessions both to be completed within 8 weeks. Group assignment was not blinded to study personnel or participants. Research evaluations were completed approximately 2 weeks prior to treatment initiation and following treatment completion.

MAIN MEASURES

Outcome measures included Dizziness Handicap Inventory (DHI) and Activities-specific Balance Confidence Scale (ABC) total scores, Sensory Organization Test (SOT) composite equilibrium and sensory input ratio scores, Head Shake SOT (HS-SOT) conditions 2 and 5, and horizontal and vertical Dynamic Visual Acuity. Separate mixed-effects models were used to compare clinical outcomes between the GVRT and IVRT groups.

RESULTS

Both groups demonstrated significant improvement from pre- to posttreatment on self-reported dizziness-related impairment (DHI [F(1,41) = 16.28, P < .001]) and balance performance with and without head movement (composite equilibrium score [F(1,41) = 16.58, P < .001, effect size [ES] = 0.43], somatosensory [F(1,41) = 6.79, P = .013, ES = 0.26], visual [F(1,41) = 6.49, P = .015, ES = 0.29], vestibular [F(1,41) = 22.31, P < .001, ES = 0.55], and HS-SOT condition 5 [F(1,38) = 23.98, P < .001, ES = 0.64]). Treatment effects did not differ between groups on any of the outcome measures.

CONCLUSIONS

We provide preliminary evidence that differences in clinical outcomes do not exist between participants receiving generalized versus individualized VR. Further research is needed to determine comparative effectiveness between these 2 treatment approaches for persistent vestibular-related symptoms following mTBI.

Neuro-Visual and Vestibular Manifestations of Concussion and Mild TBI

PURPOSE OF REVIEW

Mild traumatic brain injury, or concussion, is a major cause of disability. Vestibular and visual dysfunction following concussion is common and can negatively affect patients' well-being and prolong recovery. Etiologies of visual and vestibular symptoms are numerous, including ocular, neuro-ophthalmic, otologic, and neuro-vestibular conditions. Some etiologies are benign and may be treatable, while others are potentially vision or life-threatening, making a focused history and examination essential. This review offers an approach to the evaluation and treatment of the most common neuro-visual and vestibular impairments that may result from concussion.

RECENT FINDINGS

Treatment of concussion including exercise, computerized programs, transcranial magnetic stimulation, gene therapy, stem cell therapy, and nanoparticles has shown promise. Many novel therapies are in the pipework for visual and vestibular recovery after concussion; however, the treatment mainstay remains therapy and evaluation for co-existing diseases.

Relationship between Dizziness and the Core Vestibular Projection Injury in Patients with Mild Traumatic Brain Injury

Some studies have reported that a core vestibular projection (CVP) injury is associated with dizziness following a brain injury using diffusion tensor tractography (DTT). On the other hand, there has been no DTT study on dizziness caused by a CVP injury in patients with mild traumatic brain injury (TBI). In this study, DTT was used to examine the relationship between dizziness and CVP injury in patients with mild TBI. Forty-three patients with mild TBI and twenty-nine normal subjects were recruited. The patients were classified into two groups based on the dizziness score: group A, patients with a dizziness score less than 2 on the sub-item score for dizziness in the Rivermead Post-concussion Symptoms Questionnaire; group B, patients with a dizziness score above 2. The tract volume (TV) in group B was significantly lower than group A and the control group (p < 0.05). By contrast, the TV in group A was similar to the control group (p > 0.05). Regarding the correlation, the dizziness score of all patients showed a strong negative correlation with the TV of the CVP (r = −0.711, p < 0.05). DTT revealed the CVP injury in patients with dizziness after mild TBI. In addition, the severity of dizziness of these patients was closely related to the injury severity of the CVP.

Gaze stability in young adults with previous concussion history

BACKGROUND

Disruption of visual-vestibular interaction after concussion can cause gaze instability with head movements. The long-term impact of concussion on gaze stability is unknown.

OBJECTIVE

This cross-sectional comparative pilot study examined gaze stability in the chronic stage after concussion (greater than one year). A secondary objective was to examine the relationship between gaze stability and sleep.

METHODS

Outcome measures included: 1. Gaze stability in logMAR (mean loss of dynamic visual acuity (DVA) in the yaw and pitch planes); 2. Pittsburgh Sleep Quality Index (PSQI); 3. Epworth Sleepiness Scale (ESS). Post-Concussion Symptom Scale (PCSS), time since injury, and number of concussions were collected for the people with concussion.

RESULTS

The study sample included thirty-four adults (mean age 23.35±1.3 years). Seventeen had a history of 1-9 concussions, with a mean duration of 4.4±1.9 years since last concussion; and 17 were age and sex-matched controls. Mean pitch plane DVA loss was greater in the concussion group compared to the control group (p = 0.04). Participants with previous concussion had lower sleep quality based on the PSQI (p = 0.01) and increased daytime sleepiness based on the ESS (p = 0.01) compared to healthy controls. Mean DVA loss in the pitch plane was significantly correlated with the PSQI (r = 0.43, p = 0.01) and the ESS (r = 0.41, p = 0.02).

CONCLUSION

Significant differences in dynamic visual acuity may be found in young adults long after a concussion, compared with those who have no concussion history. Furthermore, loss of dynamic visual acuity was associated with poorer sleep quality and higher daytime sleepiness.

The development and the inter-rater agreement of a treatment protocol for vestibular/oculomotor rehabilitation in children and adolescents post-moderate-severe TBI

Introduction:There is limited evidence investigating the effect of vestibular/oculomotor rehabilitation programs in children and adolescents post moderate-severe TBI at the sub-acute stage.Objective:To describe the development of a treatment protocol for vestibular/oculomotor interventions in this population, and to assess the inter-rater agreement of this protocol as an initial step of a clinical trial.Method:The protocol was developed by 10 health professionals, address the high variability of balance performance, the high prevalence of vestibular/oculomotor abnormalities and the low prevalence of symptoms reported in this population.Results:The protocol enables the clinician to use the assessment during the treatment exercise selection. The training position was defined by the Pediatric Balance Scale. Vestibular/oculomotor exercises were selected using a quantified version of the Vestibular/Ocular Motor Screening. The exercise protocol was selected based on impairment in function or reproduction of symptoms. The protocol planning was implemented by two assessors in 27 children and adolescents post-moderate-severe TBI (median age 14.1 [6-18.4] years) in the sub-acute stage (median 40 [14-162] days since injury). Very high agreement was found (k > 0.72) in all the parameters.Conclusion: This protocol could reliably be used in a randomized control trial that assesses the effect of vestibular/oculomotor rehabilitation program in children and adolescents post moderate-severe TBI at the sub-acute stage.

Inner Ear Symptoms Are Prevalent in Patients with High Head Abbreviated Injury Scale Scores after Blunt Head Trauma

INTRODUCTION

The purpose of this article was to determine the prevalence of inner ear symptoms in patients with blunt head trauma and to explore whether the severity of head trauma was associated with the incidence of such symptoms.

METHODS

We performed a retrospective review of 56 patients admitted with blunt head trauma who underwent audiovestibular evaluation within 1 month after injury. Two scales were used to measure the severity of trauma; these were the Glasgow Coma Scale (GCS) and the Head Abbreviated Injury Scale (H-AIS). Patients with sensorineural-type hearing loss, or dizziness with nystagmus, were considered to have inner ear symptoms.

RESULTS

About half of all patients (45%) with blunt head trauma showed trauma-related inner ear symptoms. Patients with inner ear symptoms were significantly more likely to have H-AIS scores ≥4 than those without inner ear symptoms (p = 0.004), even without concomitant temporal bone fracture (p > 0.05). Also, patients with inner ear symptoms required a statistically significantly longer time (measured from admission) before undergoing their ontological evaluations than did those without such symptoms (p = 0.002), possibly due to prolonged bed rest and use of sedatives.

CONCLUSION

Thus, detailed history-taking and early evaluation using trauma scales are essential for all patients suffering from severe head trauma. It may be necessary to initiate early treatment of traumatic inner ear diseases.

Relating Self-Reported Balance Problems to Sensory Organization and Dual-Tasking in Chronic Traumatic Brain Injury

BACKGROUND

Individuals who have experienced a traumatic brain injury (TBI) often have residual balance problems. It remains unclear whether these balance problems are driven by vestibular dysfunction or gait automaticity deficits, particularly in the chronic stages of TBI recovery, because most studies include only acute/subacute cases.

OBJECTIVES

Compare performance on the Sensory Organization Test vestibular score and Dual-Task test in individuals with and without subjective balance problems at least 1 year after a TBI. Investigate the ability of each test to predict perceived balance problems.

DESIGN

Prospective cohort study.

SETTING

Rehabilitation department within a single institution.

PARTICIPANTS

Fifty adults (21-71 years) with a history of mild, moderate, or severe TBI 1 to 5 years following nonpenetrating TBI.

INTERVENTIONS

N/A.

METHODS

Measures included the Dual-Task test, Sensory Organization Test, Neurobehavioral Symptom Inventory, Dizziness Handicap Inventory, and assessments of four cognitive domains and depression. Participants who endorsed "feeling dizzy" and "loss of balance" on the Neurobehavioral Symptom Inventory were classified as symptomatic (n = 26) and others as asymptomatic (n = 24). T-tests, chi-square, and regression analyses predicting the Dizziness Handicap Inventory total score were performed.

RESULTS

Dual-task gait cost was negatively associated with the Dizziness Handicap Inventory (P = .044), controlling for depression and gender, whereas vestibular scores failed to predict balance-related disability. Symptomatic individuals endorsed more balance problems (P < .001) and depression symptoms (P = .007), had poorer dual-task cognitive output (P = .036), and slower dual-task gait velocity (P = .036) than asymptomatic participants. Groups did not differ on Sensory Organization Test scores.

CONCLUSIONS

The nature of balance problems in chronic TBI may be related to automaticity of gait. These findings suggest that patients in the chronic stages of TBI may benefit from dual-task assessments and interventions. Balance rehabilitation should be tailored to patient needs and assess cognition and affect.

Oculomotor Deficits and Symptom Severity Are Associated With Poorer Dynamic Mobility in Chronic Mild Traumatic Brain Injury

Oculomotor deficits, vestibular impairments, and persistent symptoms are common after a mild traumatic brain injury (mTBI); however, the relationship between visual-vestibular deficits, symptom severity, and dynamic mobility tasks is unclear. Twenty-three individuals (mean age 55.7 ± 9.3 years) with persistent symptoms after mTBI, who were between 3 months to 2 years post-injury were compared with 23 age and sex-matched controls. Oculomotor deficits [depth perception, near-point convergence, baseline visual acuity (BLVA), perception time], vestibular deficits (dynamic visual acuity in the pitch and yaw planes), dynamic mobility measured by the Functional Gait Assessment (FGA), and symptoms measured by the Post-Concussion Symptom Scale (PCSS) and Dizziness Handicap Inventory (DHI) were compared between groups. Participants with mTBI had poorer performance on the FGA (p < 0.001), higher symptom severity on the PCSS (p < 0.001), and higher DHI scores (p < 0.001) compared to controls. Significant differences were seen on specific items of the FGA between individuals with mTBI and controls during walking with horizontal head turns (p = 0.002), walking with vertical head tilts (p < 0.001), walking with eyes closed (p = 0.003), and stair climbing (p = 0.001). FGA performance was correlated with weeks since concussion (r = −0.67, p < 0.001), depth perception (r = −0.5348, p < 0.001), near point convergence (r = −0.4717, p = 0.001), baseline visual acuity (r = −0.4435, p = 0.002); as well as with symptoms on the PCSS (r = −0.668, p < 0.001), and DHI (r = −0.811, p < 0.001). Dynamic balance deficits persist in chronic mTBI and may be addressed using multifaceted rehabilitation strategies to address oculomotor dysfunction, post-concussion symptoms, and perception of handicap due to dizziness.

The timeframe for safe resumption of high-level mobility following traumatic brain injury is currently unknown: a systematic review

PURPOSE

To examine the safety of high-level mobility (HLM) prescription in the early sub-acute phase of recovery following moderate-to-extremely severe traumatic brain injury (TBI) with specific focus on provocation of concussion-like symptoms.

DESIGN

Systematic review. PROSPERO ID: CRD42017069369.

MAIN MEASURES

Extracted data included study design, brain injury severity, time to commence HLM, type of HLM, physiological and symptom monitoring, and rate of adverse events.

RESULTS

Nineteen studies were included in the review. Fifteen studies included participants who commenced HLM within 6 weeks of injury, with the earliest time to commencement being 3 days. Overall, adverse events and symptom monitoring were poorly reported. A total of six adverse events were reported across three studies. One of the six adverse events was a concussion-like symptom. No falls were reported. No studies monitored concussion-like symptom provocation in direct relation to HLM.

CONCLUSION

A safe timeframe for return to HLM after moderate-to-extremely severe TBI could not be determined due to insufficient reporting of symptom monitoring and adverse events. Further research into the safety of HLM in the early sub-acute rehabilitative stage after moderate-to-extremely severe TBI is required in order to better understand potential sequelae in this population.IMPLICATIONS FOR REHABILITATIONHigh-level mobility assessment and training is commonly reported in the early sub-acute phase of recovery following moderate-to-extremely severe traumatic brain injury.There is no consensus on a safe timeframe to commence high-level mobility assessment or training after moderate-to-extremely severe traumatic brain injury.High-level mobility assessment and training appears to be safe in the early sub-acute phase following moderate-to-extremely severe traumatic brain injury, however, adverse events and symptoms are poorly reported.Clinicians should continue to proceed with caution when assessing and prescribing high-level mobility for patients with moderate-to-extremely severe traumatic brain injury in the early sub-acute phase of recovery and monitor for risks such as falls and exacerbation of concussion-like symptoms.

Altered Processing of Complex Visual Stimuli in Patients with Postconcussive Visual Motion Sensitivity

BACKGROUND AND PURPOSE

Vestibular symptoms are common after concussion. Vestibular Ocular Motor Screening identifies vestibular impairment, including postconcussive visual motion sensitivity, though the underlying functional brain alterations are not defined. We hypothesized that alterations in multisensory processing are responsible for postconcussive visual motion sensitivity, are detectable on fMRI, and correlate with symptom severity.

MATERIALS AND METHODS

Twelve patients with subacute postconcussive visual motion sensitivity and 10 healthy control subjects underwent vestibular testing and a novel fMRI visual-vestibular paradigm including 30-second "neutral" or "provocative" videos. The presence of symptoms/intensity was rated immediately after each video. fMRI group-level analysis was performed for a "provocative-neutral" condition. Z-statistic images were nonparametrically thresholded using clusters determined by Z > 2.3 and a corrected cluster significance threshold of P = .05. Symptoms assessed on Vestibular Ocular Motor Screening were correlated with fMRI mean parameter estimates using Pearson correlation coefficients.

RESULTS

Subjects with postconcussive visual motion sensitivity had significantly more Vestibular Ocular Motor Screening abnormalities and increased symptoms while viewing provocative videos. While robust mean activation in the primary and secondary visual areas, the parietal lobe, parietoinsular vestibular cortex, and cingulate gyrus was seen in both groups, selective increased activation was seen in subjects with postconcussive visual motion sensitivity in the primary vestibular/adjacent cortex and inferior frontal gyrus, which are putative multisensory visual-vestibular processing centers. Moderate-to-strong correlations were found between Vestibular Ocular Motor Screening scores and fMRI activation in the left frontal eye field, left middle temporal visual area, and right posterior hippocampus.

CONCLUSIONS

Increased fMRI brain activation in visual-vestibular multisensory processing regions is selectively seen in patients with postconcussive visual motion sensitivity and is correlated with Vestibular Ocular Motor Screening symptom severity, suggesting that increased visual input weighting into the vestibular network may underlie postconcussive visual motion sensitivity.

Vestibular agnosia in traumatic brain injury and its link to imbalance

Vestibular dysfunction, causing dizziness and imbalance, is a common yet poorly understood feature in patients with TBI. Damage to the inner ear, nerve, brainstem, cerebellum and cerebral hemispheres may all affect vestibular functioning, hence, a multi-level assessment—from reflex to perception—is required. In a previous report, postural instability was the commonest neurological feature in ambulating acute patients with TBI. During ward assessment, we also frequently observe a loss of vertigo sensation in patients with acute TBI, common inner ear conditions and a related vigorous vestibular-ocular reflex nystagmus, suggesting a ‘vestibular agnosia’. Patients with vestibular agnosia were also more unbalanced; however, the link between vestibular agnosia and imbalance was confounded by the presence of inner ear conditions. We investigated the brain mechanisms of imbalance in acute TBI, its link with vestibular agnosia, and potential clinical impact, by prospective laboratory assessment of vestibular function, from reflex to perception, in patients with preserved peripheral vestibular function. Assessment included: vestibular reflex function, vestibular perception by participants’ report of their passive yaw rotations in the dark, objective balance via posturography, subjective symptoms via questionnaires, and structural neuroimaging. We prospectively screened 918 acute admissions, assessed 146 and recruited 37. Compared to 37 matched controls, patients showed elevated vestibular-perceptual thresholds (patients 12.92°/s versus 3.87°/s) but normal vestibular-ocular reflex thresholds (patients 2.52°/s versus 1.78°/s). Patients with elevated vestibular-perceptual thresholds [3 standard deviations (SD) above controls’ average], were designated as having vestibular agnosia, and displayed worse posturography than non-vestibular-agnosia patients, despite no difference in vestibular symptom scores. Only in patients with impaired postural control (3 SD above controls’ mean), whole brain diffusion tensor voxel-wise analysis showed elevated mean diffusivity (and trend lower fractional anisotropy) in the inferior longitudinal fasciculus in the right temporal lobe that correlated with vestibular agnosia severity. Thus, impaired balance and vestibular agnosia are co-localized to the inferior longitudinal fasciculus in the right temporal lobe. Finally, a clinical audit showed a sevenfold reduction in clinician recognition of a common peripheral vestibular condition (benign paroxysmal positional vertigo) in acute patients with clinically apparent vestibular agnosia. That vestibular agnosia patients show worse balance, but without increased dizziness symptoms, explains why clinicians may miss treatable vestibular diagnoses in these patients. In conclusion, vestibular agnosia mediates imbalance in traumatic brain injury both directly via white matter tract damage in the right temporal lobe, and indirectly via reduced clinical recognition of common, treatable vestibular diagnoses.

Alterations in Resting-State Functional Brain Connectivity and Correlations with Vestibular/Ocular-Motor Screening Measures in Postconcussion Vestibular Dysfunction

BACKGROUND AND PURPOSE

Vestibular symptoms after concussion are common and associated with protracted recovery. The purpose of this study is to define resting-state functional MRI (rs-fMRI) brain connectivity alterations in patients with postconcussion vestibular dysfunction (PCVD) and correlations between rs-fMRI connectivity and symptoms provoked during Vestibular/Ocular-Motor Screening (VOMS) assessment.

METHODS

Prospective IRB approved study.

STUDY GROUP

12 subjects with subacute PCVD (2-10 weeks); control group: 10 age-matched subjects without history of concussion or vestibular impairment. Both groups underwent clinical vestibular assessment. rs-fMRI was acquired on 3.0T Siemens Trio with a 12-channel head coil. rs-fMRI data analysis included independent component analysis-based functional connectivity group differences, graph theory analysis, and ROI-to-ROI connectivity correlation analysis with VOMS clinical derivatives. Group difference maps between resting-state networks were calculated using dual regression method and corrected for multiple comparisons. Correlation analysis between ROI-to-ROI rs-fMRI brain activation and VOMS assessment ratings was performed using Pearson correlation coefficient, with a significance threshold of P ≤ .05.

RESULTS

Compared to controls, PCVD group demonstrated significantly increased rs-fMRI connectivity between the default-mode network and right middle frontal gyrus and right postcentral gyrus; and between a vestibular-sensorimotor network and right prefrontal cortex. Significant positive correlations were found between clinical derivative VOMS scores and components of the vestibular, visual networks, and multisensory processing cortical representations.

CONCLUSION

Altered rs-fMRI brain connectivity with increased connectivity of visual input, multisensory processing, and spatial memory in PCVD is correlative with clinical derivative VOMS scores, suggesting maladaptive brain plasticity underlying vestibular symptomatology.

Measurement Properties of the Dizziness Handicap Inventory-Children and Adolescents for Children and Adolescents Postconcussion

PURPOSE

The purpose of this study was to examine and report the construct validity, internal consistency, and item structure of the Dizziness Handicap Inventory-Children and Adolescents (DHI-CA) in postconcussion children and adolescents.

METHODS

A retrospective chart review was conducted for 132 participants. Data were extracted on the DHI-CA, Sports Concussion Assessment Tool-III symptom inventory, and Vestibulo-ocular Motor Screening. The DHI-CA was examined for validity, internal consistency, and factor structure.

RESULTS

The DHI-CA had fair convergent validity (rs = 0.30-0.40), but discriminant validity findings were inconclusive. The functional subscale demonstrated least consistent loadings and 4 items had cross-loading. Reliability analysis indicated possible item redundancy given that the overall Cronbach α was higher than the subscales.

CONCLUSION

Despite demonstrating convergent validity, structural inconsistencies and possible item redundancy warrant further exploration and restructuring of the DHI-CA. Caution is recommended while making clinical decisions based on the DHI-CA results alone.

VIDEO ABSTRACT

For more insights from the authors, see Supplemental Digital Content 1, available at: http://links.lww.com/PPT/A303.

The integrated functions of the cardiac autonomic and vestibular/oculomotor systems in adolescents following severe traumatic brain injury and typically developing controls

INTRODUCTION

The cardiac autonomic control system (CACS) is frequently impaired post-traumatic brain injury (TBI). However, the prevalence of vestibular/oculomotor impairment is less studied. These two systems interact during position change and contribute to blood-pressure regulation through the vestibulo-sympathetic reflex. Aim: To assess the CACS, the vestibular/oculomotor systems and their integrative function in adolescents post-TBI compared to typically-developing (TD) adolescents. Methods: 19 adolescents in the subacute stage following a severe TBI (14-117 days post injury) and 19 age and sex matched TD controls were recruited. Heart Rate Variability (HRV) was assessed at rest and during a modified tilt-test. A quantified version of the Vestibular/Ocular-Motor Screening (VOMS) was also administered. Results: At rest, the TBI group had higher HR and lower HRV values (p < .001). All participants with TBI demonstrated impairments in the VOMS (median of positive tests: 5 [range 2-9]) compared to only 6 out of 19 in the TD participants (median 0 [0-2]) (z = -5.34; p < .001). In response to the modified tilt test, the HRV increased significantly in the lifting period and decreased significantly once in standing only in the TBI group (z = -2.85, p = .025). Conclusion: Adolescents post severe TBI demonstrated impairments in the CACS, positive tests on the VOMS and significantly greater changes in the modified tilt test as compared to TD. Clinical trial gov. number: NCT03215082.

Veterans with dizziness recruit compensatory saccades in each semicircular canal plane although VOR gain is normal

BACKGROUND

Exposure to brain injury via blast or blunt mechanisms disrupts multiple sensorimotor systems simultaneously. Large numbers of US Gulf War era and Operation Iraqi/Enduring Freedom veterans with traumatic brain injury (TBI) are suffering the symptom of dizziness - presumed due to "Multi-Sensory Impairment", a clinical pattern of damage to the auditory, visual and vestibular sensorimotor systems.

OBJECTIVE

To describe the oculomotor response to rapid head rotation in a population of veterans with dizziness. We also describe the reliability of using the video head impulse test (vHIT) in a veteran population.

METHODS

We used the vHIT to evaluate the vestibular-ocular reflex (VOR) gain and presence of compensatory saccades (CS) in each semicircular canal of 81 veterans (31% TBI) with dizziness. Data was collected using the ICS Otometric™ vHIT. Data was processed using both the Otometric™ software and custom software written in MATLAB™. This data was evaluated through Kruskal-Wallis rank-sum test and analysis of regression.

RESULTS

Veterans with dizziness recruit CS in all semicircular canal planes even though their VOR gain is normal. The vHIT is a reliable clinical test to quantify the metrics of the VOR and CS in veterans.

CONCLUSION

Veterans with dizziness symptoms use compensatory saccades in all planes of semicircular canal rotation, despite having normal peripheral VOR gain during rapid head rotation. The video head impulse test is a stable measure of vestibular slow phase and metrics of compensatory saccades in veterans with dizziness.

Vestibular and Balance Dysfunction Following Sport-Related Concussion

Purpose

Sport-related concussion is a significant public health concern that requires a multidisciplinary team to appropriately manage. Athletes often report dizziness and imbalance following concussion, and these symptoms can predict increased time to recover. Vestibular diagnostic evaluations provide important information regarding the athlete's oculomotor, gaze stability, and balance function in order to identify deficits for rehabilitation. These measures also describe objective function helpful for determining when an athlete is ready to return to play. The purpose of this clinical focus article is to provide background on the current understanding of the effects of concussion on the peripheral and central vestibular system, as well as information on a protocol that can be used for acute concussion assessment. Case studies describing 3 common postconcussion presentations will highlight the usefulness of this protocol.

Conclusion

Sport-related concussion is a highly visible disorder with many symptoms that may be evaluated in the vestibular clinic. A thoughtful protocol evaluating the typical presentation of these patients may help guide the multidisciplinary team in determining appropriate management and clearance for return to sport.

Altered White Matter Integrity after Mild to Moderate Traumatic Brain Injury

(1) Background: White matter changes among individuals with mild-to-moderate traumatic brain injury (TBI) may be sensitive imaging markers reflecting functional impairment, particularly in the context of post-concussion syndrome. The objective of this study was to examine the altered white matter integrity in mild-to-moderate TBI patients compared with age-matched normal controls. (2) Methods: Diffusion tensor imaging data from 15 individuals with TBI and 15 control subjects were retrospectively obtained. We investigated and compared white matter integrity in both groups, with regard to fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD) and examined the relationship with cognitive dysfunction and impaired balance in patients. (3) Results: In comparison with controls, the TBI patients had significantly decreased FA as well as increased RD, in the right corticospinal tract. Decreased RD was observed in the left cerebellar area near the middle cerebellar peduncle. Decreased AD was observed in the left inferior cerebellar peduncle, showing positive correlation with poor balance control. We observed decreased FA and increased AD in the left superior longitudinal fasciculus showing positive and negative correlation, respectively, with cognitive function in the TBI group. (4) Conclusions: Altered white matter integrity in mild-to-moderate TBI cases may be indicative of cognitive dysfunction and impaired balance.

Balance Assessment in Traumatic Brain Injury: A Comparison of the Sensory Organization and Limits of Stability Tests

Balance problems are common after a traumatic brain injury (TBI). Symptoms of dizziness, unsteadiness, or imbalance have been most frequently attributed to sensory organization problems involving the use of visual, proprioceptive, and/or vestibular information for postural control. These problems can be assessed with the Sensory Organization Test (SOT). However, as head trauma can affect any brain region, areas responsible for voluntary control of movements involved in dynamic balance tasks, such as the motor cortex and its projections, could also be compromised, which would likely affect one's limits of stability. The Limits of Stability (LOS) balance test has received little attention in TBI. In the present study, we compared the prevalence of SOT versus LOS abnormalities in a cohort of 48 patients, the majority classified as having mild or moderate chronic TBI. Compared with a normative database provided by the balance testing manufacturer, a larger portion of our cohort presented abnormalities in the LOS test. Dizziness Handicap Inventory (DHI) results indicated mild disability, with the five activities most frequently endorsed as problematic being: looking up, performing quick head movements, performing ambitious such as sports or dancing activities, feeling frustrated, and performing strenuous house/yard work. Although regression analysis revealed that both tests significantly predicted subjective scores on the DHI, more LOS than SOT testing variables were important predictors of DHI results indicating disability. These results suggest that the LOS test is an informative tool that should be included in any objective balance evaluations that screen TBI patients with balance complaints.

Results From a Randomized Controlled Trial to Address Balance Deficits After Traumatic Brain Injury

OBJECTIVE

To evaluate the efficacy of an in-home 12-week physical therapy (PT) intervention that utilized a virtual reality (VR) gaming system to improve balance in individuals with traumatic brain injury (TBI).

SETTING

Home-based exercise program (HEP).

PARTICIPANTS

Individuals (N=63; traditional HEP n=32; VR n=31) at least 1 year post-TBI, ambulating independently within the home, not currently receiving PT services.

MAIN OUTCOME MEASURES

Primary: Community Balance and Mobility Scale (CB&M); Secondary: Balance Evaluation Systems Test (BESTest), Activities-Specific Balance Confidence Scale (ABC), Participation Assessment with Recombined Tools-Objective (PART-O).

RESULTS

No significant between-group differences were observed in the CB&M over the study duration (P=.9983) for individuals who received VR compared to those who received a HEP to address balance deficits after chronic TBI nor in any of the secondary outcomes: BESTest (P=.8822); ABC (P=.4343) and PART-O (P=.8822). However, both groups demonstrated significant improvements in CB&M and BESTest from baseline to 6, 12, and at 12 weeks follow-up (all P's <.001). Regardless of treatment group, 52% of participants met or exceeded the minimal detectable change of 8 points on the CB&M at 24 weeks and 38% met or exceeded the minimal detectable change of 7.81 points on the BESTest.

CONCLUSION

This study did not find that VR training was more beneficial than a traditional HEP for improving balance. However, individuals with chronic TBI in both treatment groups demonstrated improvements in balance in response to these interventions which were completed independently in the home environment.

Concussion - Part I: The need for a multifaceted assessment

INTRODUCTION

Concussion is among the most commonly occurring sport and recreation injuries in today's society. An understanding of the heterogenous nature of concussion will assist in directing a multifaceted and comprehensive interdisciplinary assessment following injury.

PURPOSE

The purpose of this masterclass article is to summarize the current state of the evidence in the area of concussion, describe typical symptom presentations and assessment techniques that may assist in directing appropriate management following concussion.

IMPLICATIONS

A comprehensive assessment including a thoughtful differential diagnosis will assist the clinician to direct care appropriately and efficiently in individuals who have suffered a concussion.

Treatment of Pediatric Concussion

Concussions have gained attention in medical literature, legal literature, and lay media over the past several years as a public health affecting children, particularly those who do not improve in the first few days after an injury. We discuss strategies for acute management immediately after a concussion and an introduction to medical and non-medical options for treatment of the complex symptoms that persist in some patients with concussions. We examine the role of rest and exercise during recovery. We briefly discuss the role of the multidisciplinary approach to concussion in a setting that engages multiple specialists. Finally, we address policy changes related to sport-concussions and their efficacy in improving long term outcomes.

Peripheral Vestibular Organ Degeneration After Temporal Bone Fracture: A Human Otopathology Study

OBJECTIVES/HYPOTHESIS

Vestibular symptoms are a common sequela of temporal bone fractures (TBFs). The mechanisms of injury to the peripheral vestibular system following TBF, however, are not well described. Herein, we aimed to investigate the histopathology of the peripheral vestibular system in patients who sustained TBFs.

STUDY DESIGN

Retrospective human specimen analysis.

METHODS

Specimens from the National Temporal Bone Pathology Registry with (cases) and without (controls) TBFs were evaluated. Specimens were analyzed by light microscopy for vestibular hair cell and/or dendritic degeneration, presence of endolymphatic hydrops, blockage of the endolymphatic duct, and number of Scarpa ganglion cells (ScGCs) in the superior and inferior vestibular nerves.

RESULTS

Seven temporal bones (TBs) from five individuals with TBFs, and seven TBs from six age-matched individuals without a history of head injury met inclusion and exclusion criteria. All fractures involved the otic capsule. Severe degeneration of the cristae was identified in the semicircular canals in all TBF cases. The utricular and saccular maculae showed mild to severe degeneration in the TBF cases. Vestibular hydrops (n = 2 TBs) and blockage of the endolymphatic duct (n = 3 TBs) were also present in the TBF cases. There was a decrease of 52.6% in the mean total ScGC count in the TBF cases (n = 3 TBs) compared to age-matched controls (n = 7 TBs, P = .015). There was a mean loss of 53% of the ScGCs in the superior vestibular nerve and a mean loss of 52.3% of the ScGCs in the inferior vestibular nerve compared to age-matched controls (P = .033 and P = .021, respectively).

CONCLUSIONS

In a cohort of patients with TBFs, there were distinct peripheral vestibular changes including reduction of ScGCs.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:752-760, 2020.

A Pilot Randomised Double-Blind Study of the Tolerability and efficacy of repetitive Transcranial Magnetic Stimulation on Persistent Post-Concussion Syndrome

This study investigates the effect of Repetitive Transcranial Magnetic Stimulation (rTMS) on persistent post-concussion syndrome (PCS). The study design was a randomized (coin toss), placebo controlled, and double-blind study. Thirty-seven participants with PCS were assessed for eligibility; 22 were randomised and 18 completed the study requirements. Half the participants with PCS were given an Active rTMS intervention and the other half given Sham rTMS over 3 weeks. Follow ups were at the end of treatment and at 30 and 60 days. The primary outcome measure was the Rivermead Post-Concussion Symptoms Questionnaire (RPQ3 & RPQ13). The results indicate participants with more recent injuries (<12 month), who received Active rTMS, showed significant improvements compared to those of: 1) the same subgroup who received Sham, and 2) those with a longer duration of injury (>14 months) who received Active rTMS. This improvement predominantly manifested in RPQ13 in the follow up periods 1 and 2 months after the intervention (RPQ13 change (mean ± SD): at 1 month, Active = −21.8 ± 6.6, Sham = −2.2 ± 9.8; at 2 months, Active = −21.2 ± 5.3, Sham = −5.4 ± 13.7). No improvement was found in the subgroup with longer duration injuries. The results support rTMS as a tolerable and potentially effective treatment option for individuals with a recent (<1 year) concussion.

Balance in chronic traumatic brain injury: correlations between clinical measures and a self-report measure

OBJECTIVE

To assess associations among commonly used self-report and clinical measures of balance in chronic TBI.

DESIGN

Cross-sectional analysis of balance in a convenience sample of individuals at least one year post TBI.

MAIN OUTCOME MEASURES

Activities-Specific Balance Confidence Scale (ABC) (self-reported balance impairment), Community Balance and Mobility Scale (CB&M) (clinical measure validated in TBI), and Balance Evaluation Systems Test (BESTest) (clinical measure not validated in TBI).

METHODS

Fifty-nine individuals (64% male, mean age 48.2 years) ambulating independently within the home participated in testing. Pearson correlation coefficients were used to quantify the direction and magnitude of the relationships among the three balance impairment measures.

RESULTS

A significant positive correlation was noted between the ABC and CB&M (r = 0.42, p = 0.0008), between the ABC and BESTest (r = 0.46, p = 0.0002), and between the CB&M and BESTest (r = 0.86, p < 0.0001).

CONCLUSIONS

This is the first study we are aware of in the chronic moderate to severe TBI population directly comparing patient's self-reported balance impairment with clinical measures. Positive correlations were found between the self-report measure and both clinical measures. Overall, individuals with chronic TBI tend to self-report less impaired balance than clinical measures indicate. These results provide preliminary evidence to support the need for validation of the BESTest in this population.

ABBREVIATIONS

ABC: Activities-specific balance confidence scale; BESTest: balance evaluation systems test; BOS: base of support; COM: center of mass; CB&M: community balance and mobility scale; CI: confidence interval; IQR: interquartile range; PTs: physical therapists; SD: standard deviation; SE: standard error; TBI: traumatic brain injury.

Electrophysiological testing in concussion: A guide to clinical applications

The diagnosis of mild traumatic brain injury in concussion is difficult since it is often unwitnessed, the patient’s recall is unreliable and initial clinical examination is often unrevealing, correlating poorly with the extent of brain injury. At present, there are no objective biomarkers of mild traumatic brain injury in concussion. Thus, a sensitive gold standard test is required to enable the effective and safe triage of patients who present to the acute services. As well as triage, objective monitoring of patients’ recovery over time and separate from clinical features that patients may develop following the injury (e.g. depression and migraine) is also needed. In contrast to neuroimaging, which is widely used to investigate traumatic brain injury patients, electrophysiology is readily available, is cheap and there are internationally recognized standardised methodologies. Herein, we review the existing literature on electrophysiological testing in concussion and mild traumatic brain injury; specifically, electroencephalogram, polysomnography, brainstem auditory evoked potentials, electro- and videonystagmography, vestibular evoked myogenic potentials, visually evoked potentials, somatosensory evoked potentials and transcranial magnetic stimulation.

The Gaze Stabilization Test Following Concussion

BACKGROUND

Concussion can cause vestibular dysfunction and oculomotor abnormalities which can lead to dizziness and protracted recovery time. There are few clinically useful, functional measures of the vestibulo-ocular reflex (VOR) post-concussion.

PURPOSE

The purpose of this study was to examine the gaze stabilization test (GST) in those referred for vestibular physical therapy following concussion, to determine the association between GST and other measures of recovery following concussion, and to examine the effect of demographic variables on GST performance.

RESEARCH DESIGN

Retrospective chart review.

STUDY SAMPLE

One hundred fifty-eight individuals who sustained a concussion and were referred to vestibular physical therapy.

DATA COLLECTION AND ANALYSIS

Horizontal and vertical GST scores (HGST and VGST), neurocognitive testing results, and demographic data were extracted retrospectively from the patient health record. Correlations between GST velocity and neurocognitive test results and between GST and patient-reported outcomes were examined. Differences in GST performance among patient subgroups were examined using one-way analysis of variance.

RESULTS

Subjects included individuals aged 12 to 43 years (mean = 20, standard deviation [SD] = 7), with most having sport-related concussion (67%). The mean time from injury to GST was 215 days (SD = 241) and the mean time from physical therapy evaluation to GST was 48 days (SD = 54). HGST and VGST had a weak positive correlation to the Activities-Specific Balance Confidence Scale (r = 0.20, r = 0.21) and weak negative correlation to the Dizziness Handicap Inventory (r = -0.18, r = -0.22). HGST had a weak positive correlation to the visual motor processing speed domain of the immediate post-concussion assessment and cognitive test (r = 0.20). Male patients achieved significantly higher velocities than female patients on HGST and VGST (p = 0.02, p = 0.01).

CONCLUSIONS

The present study details the use of GST in patients with concussion and demonstrates an association with common outcome measures in vestibular rehabilitation. Results indicate that patients who achieved higher velocities on GST perceived lower handicap due to dizziness and had higher confidence in their balance. GST may be a relevant test of VOR in this population, as it is a more functional test of the VOR required for sports. Future work is needed to further evaluate the role of GST in concussion management.

Investigating the validity and reliability of Electrovestibulography (EVestG) for detecting post-concussion syndrome (PCS) with and without comorbid depression

Features from Electrovestibulography (EVestG) recordings have been used to classify and measure the severity of both persistent post-concussion syndrome (PCS) and major depressive disorder. Herein, we examined the effect of comorbid depression on the detection of persistent PCS using EVestG. To validate our previously developed EVestG classifier for PCS detection, the classifier was tested with a new blind dataset (N = 21). The unbiased accuracy for identifying the new PCS from controls was found to be >90%. Next, the PCS group (N = 59) was divided into three subgroups: PCS with no-depression (n = 18), PCS with mild-depression (n = 27) and PCS with moderate/severe-depression (n = 14). When moderate/severe depression was present, PCS classification accuracy dropped to 83%. By adding an EVestG depression feature from a previous study, separation accuracy of each PCS subgroup from controls was >90%. A four and three-group (excluding mild-depression subgroup) classification, achieved an accuracy of 74% and 81%, respectively. Correlation analysis indicated a significant correlation (R = 0.67) between the depression feature and the MADRS depression score as well as between the PCS-specific feature and Rivermead Post-Concussion Questionnaire (RPQ) (R = −0.48). No significant correlation was found between the PCS-specific feature and the MADRS score (R = 0.20) or between RPQ and the depression feature (R = 0.12). The (PCS-specific and depression-specific) EVestG features used herein have the potential to robustly detect and monitor changes, relatively independently, in both persistent PCS and its depression comorbidity. Clinically, this can be particularly advantageous.

The effects of vestibular rehabilitation on dizziness and balance problems in patients after traumatic brain injury: a randomized controlled trial

OBJECTIVE:

To investigate the effects of group-based vestibular rehabilitation in patients with traumatic brain injury.

DESIGN:

A single-blind randomized controlled trial.

SETTING:

University Hospital (recruitment and baseline assessments) and Metropolitan University (experimental intervention).

SUBJECTS:

A total of 65 patients (45 women) with mild-to-moderate traumatic brain injury (mean age 39.4 ± 13.0 years) were randomly assigned to intervention ( n = 33) or control group ( n = 32).

INTERVENTION:

Group-based vestibular rehabilitation for eight weeks. Participants were tested at baseline (3.5 ± 2.1 months after injury) and at two post-intervention follow-ups (2.7 ± 0.8 and 4.4 ± 1.0 months after baseline testing).

MAIN MEASURES:

Primary outcome: Dizziness Handicap Inventory. Secondary outcome: High-Level Mobility Assessment Tool. Other outcomes: Vertigo Symptom Scale; Rivermead Post-concussion Symptoms Questionnaire; Hospital Anxiety and Depression Scale; and Balance Error Scoring System. Between-group differences were analyzed with a linear mixed-model analysis for repeated measurements.

RESULTS:

At baseline, no group differences were revealed (personal factors, clinical characteristics and outcome measures). At the first follow-up, statistically significant mean differences in favor of the intervention were found in the primary (-8.7, 95% confidence interval (CI): -16.6 to -0.9) and secondary outcomes (3.7 points, 95% CI: 1.4-6.0). At the second follow-up, no significant between-group differences were found. No significant between-group differences in the other outcomes were found at the two follow-ups.

CONCLUSION:

The intervention appeared to speed up recovery for patients with dizziness and balance problems after traumatic brain injury. However, the benefits had dissipated two months after the end of the intervention.