A Case-Oriented Approach Exploring the Relationship Between Visual and Vestibular Disturbances and Problems of Higher-Level Mobility in Persons With Traumatic Brain Injury

Pathway of care for visual and vestibular rehabilitation after mild traumatic brain injury: a critical review

PRIMARY OBJECTIVE

To review the pathway to care for treatment and management of patients receiving visual and vestibular rehabilitation after mild traumatic brain injury (mTBI).

METHODS & PROCEDURES

English scientific peer-reviewed articles from PubMed, CINAHL, Embase, and PsycINFO between 2000 and 2020 were first screened by title and abstract, then those selected underwent full-text review and analysis.

MAIN OUTCOMES & RESULTS

The database search yielded 1640 results and after title and abstract review, 75 articles were selected for full-text screening, from which 8 were included in the qualitative synthesis. Current evidence includes a limited number of retrospective cohort studies and case studies.

CONCLUSIONS

Many patients with visual and vestibular deficits following mTBI do not receive rehabilitation services until months following their injury as there is no standardized pathway to care for patients for visual and vestibular rehabilitation. Barriers to establishing a standardized pathway are the lack of natural history data for visual and vestibular function following mTBI and the lack of randomized clinical trials establishing the efficacy of rehabilitation in patients following mTBI.

Vision Evaluation Tools for Adults With Acquired Brain Injury: A Scoping Review

Background. Unrecognized visual deficits (VDs) following an acquired brain injury (ABI) may impact clients’ rehabilitation. Little is known about evaluation tools used in vision rehabilitation. Purpose. To systematically explore the literature describing evaluation tools used for VD on adults with ABI. Method. Using a scoping review methodology, we searched in MEDLINE(Ovid), Embase, CINAHL, PsycINFO, and the grey literature from inception to 2020. Quantitative and thematic analyses were performed. Findings. Of the 83 studies reporting on 86 evaluation tools, 47% used multiple tools to assess VD. Tools were mostly used by occupational therapists and psychologists to evaluate intermediate, intermediate to high, and high-level visual skills. Clinicians tend to select specific tools that focus on different levels of the hierarchy of visual skills. Implications. Future research should investigate the optimal timeframe for assessment of VD and the psychometric properties of tools to ensure comprehensive VD evaluation.

Visual Dysfunction after Repetitive Mild Traumatic Brain Injury in a Mouse Model and Ramifications on Behavioral Metrics

Mild traumatic brain injury (mTBI) is a major cause of morbidity and mortality with a poorly understood pathophysiology. Animal models have been increasingly utilized to better understand mTBI and recent research has identified visual deficits in these models that correspond to human literature. While visual impairment is being further characterized within TBI, the implications of impaired vision on behavioral tasks commonly utilized in animal models has not been well described thus far. Visual deficits may well confound behavioral tests that are believed to be isolated to cognitive functioning such as learning and memory. We utilized a mouse model of repetitive mTBI (rmTBI) to further characterize visual deficits using an optomotor task, electroretinogram, and visually evoked potential, and located likely areas of damage to the visual pathway. Mice were tested on multiple behavioral metrics, including a touchscreen conditional learning task to better identify the contribution of visual dysfunction to behavioral alterations. We found that rmTBI caused visual dysfunction resulting from damage distal to the retina that likely involves pathology within the optic nerve. Moreover, loss of vision led to poorer performance of rmTBI animals on classic behavioral tests such as the Morris water maze that would otherwise be attributed solely to learning and memory deficits. The touchscreen conditional learning task was able to differentiate rmTBI induced learning and memory dysfunction from visual impairment and is a valuable tool for elucidating subtle changes resulting from TBI.

Evaluating the Vestibulo-Ocular Reflex Following Traumatic Brain Injury: A Scoping Review

Purpose:To identify the tests and tools used to evaluate vestibulo-ocular reflex (VOR) function after traumatic brain injury (TBI) in all age groups and across TBI severity.Methods: An electronic search was conducted to include relevant peer-reviewed literature published up to November 2019. Studies included those done with humans, of all ages, and had assessments of oculomotor and/or vestibulo-ocular function in TBI.Results: Of the articles selected (N = 48), 50% were published in 2018/2019. A majority targeted mild TBI, with equal focus on non-computerized versus computerized measures of VOR. Computerized assessment tools used were videonystagmography, dynamic visual acuity/gaze stability, rotary chair, and caloric irrigation. Non-computerized tests included the head thrust, dynamic visual acuity, gaze stability, head shaking nystagmus, rotary chair tests and the vestibular/oculomotor screening tool. High variability in administration protocols were identified. Namely: testing environment, distances/positioning/equipment used, active/passive state, procedures, rotation frequencies, and variables observed.Conclusions: There is a rapid growth of literature incorporating VOR tests in mild TBI but moderate and severe TBI continues to be under-represented. Determining how to pair a clinical test with a computerized tool and developing standardized protocols when administering tests will help in developing an optimal battery assessing the VOR in TBI.

Pediatric traumatic brain injury and abusive head trauma

Childhood traumatic brain injury (TBI) commonly occurs during brain development and can have direct, immediately observable neurologic, cognitive, and behavioral consequences. However, it can also disrupt subsequent brain development, and long-term outcomes are a combination of preinjury development and abilities, consequences of brain injury, as well as delayed impaired development of skills that were immature at the time of injury. There is a growing number of studies on mild TBI/sport-related concussions, describing initial symptoms and their evolution over time and providing guidelines for effective management of symptoms and return to activity/school/sports. Mild TBI usually does not lead to long-term cognitive or academic consequences, despite reports of behavioral/psychologic issues postinjury. Regarding moderate to severe TBI, injury to the brain is more severe, with evidence of a number of detrimental consequences in various domains. Patients can display neurologic impairments (e.g., motor deficits, signs of cerebellar disorder, posttraumatic epilepsy), medical problems (e.g., endocrine pituitary deficits, sleep-wake abnormalities), or sensory deficits (e.g., visual, olfactory deficits). The most commonly reported deficits are in the cognitive-behavioral field, which tend to be significantly disabling in the long-term, impacting the development of autonomy, socialization and academic achievement, participation, quality of life, and later, independence and ability to enter the workforce (e.g., intellectual deficits, slow processing speed, attention, memory, executive functions deficits, impulsivity, intolerance to frustration). A number of factors influence outcomes following pediatric TBI, including preinjury stage of development and abilities, brain injury severity, age at injury (with younger age at injury most often associated with worse outcomes), and a number of family/environment factors (e.g., parental education and occupation, family functioning, parenting style, warmth and responsiveness, access to rehabilitation and care). Interventions should identify and target these specific factors, given their major role in postinjury outcomes. Abusive head trauma (AHT) occurs in very young children (most often <6 months) and is a form of severe TBI, usually associated with delay before appropriate care is sought. Outcomes are systematically worse following AHT than following accidental TBI, even when controlling for age at injury and injury severity. Children with moderate to severe TBI and AHT usually require specific, coordinated, multidisciplinary, and long-term rehabilitation interventions and school adaptations, until transition to adult services. Interventions should be patient- and family-centered, focusing on specific goals, comprising education about TBI, and promoting optimal parenting, communication, and collaborative problem-solving.

Dizziness-related disability following mild-moderate traumatic brain injury

OBJECTIVE

To investigate the associations between dizziness-related disability after mild- moderate Traumatic Brain Injury (TBI) and personal factors, injury-related factors and post-injury functioning using the International Classification of Functioning, Disability and Health (ICF) as a framework.

METHODS

Baseline assessments for a Randomised Controlled Trial (RCT) were obtained for 65 patients (mean age 39.2 years; SD 12.9 years; 70.8% women) who had dizziness and reduced balance 2-6 months after injury. The severity of the brain injury, physical and psychological self-reported symptoms and results from the performance based tests were used as independent variables. The main outcome measure (dependent variable) was the Dizziness Handicap Inventory (DHI).

RESULTS

Multivariate analyses showed that, the dizziness-related disability was predicted by pre-injury comorbidities (p ≤ 0.05) and was associated with self-reported vertigo symptoms (p < 0.001), reduced performance-based balance (p ≤ 0.05) and psychological distress (p ≤ 0.05). These factors accounted for 62% of the variance in DHI.

CONCLUSION

Dizziness and balance problems after mild-moderate TBI appear to be complex biopsychosocial phenomena. Assessments linked to the ICF domains of functioning might contribute to a broader understanding of the needs of these patients. Further, prospective clinical studies with non-dizzy control groups are needed to investigate dizziness-related disability after TBI.

Vestibular Rehabilitation After Traumatic Brain Injury: Case Series

BACKGROUND AND PURPOSE

There has been an increasing focus on vestibular rehabilitation (VR) after traumatic brain injury (TBI) in recent years. However, detailed descriptions of the content of and patient responses to VR after TBI are limited. The purposes of this case series are (1) to describe a modified, group-based VR intervention and (2) to examine changes in self-reported and performance-based outcome measures.

CASE DESCRIPTION

Two women and 2 men (aged 24-45 years) with mild TBI, dizziness, and balance problems participated in an 8-week intervention consisting of group sessions with guidance, individually modified VR exercises, a home exercise program, and an exercise diary. Self-reported and performance-based outcome measures were applied to assess the impact of dizziness and balance problems on functions related to activity and participation.

OUTCOMES

The intervention caused no adverse effects. Three of the 4 patients reported reduced self-perceived disability because of dizziness, diminished frequency and severity of dizziness, improved health-related quality of life, reduced psychological distress, and improved performance-based balance. The change scores exceeded the minimal detectable change, indicating a clinically significant change or improvement in the direction of age-related norms. The fourth patient did not change or improve in most outcome measures.

DISCUSSION

A modified, group-based VR intervention was safe and appeared to be viable and beneficial when addressing dizziness and balance problems after TBI. However, concurrent physical and psychological symptoms, other neurological deficits, and musculoskeletal problems might influence the course of central nervous system compensation and recovery. The present case series may be useful for tailoring VR interventions to patients with TBI. Future randomized controlled trials are warranted to evaluate the short- and long-term effects of VR after TBI.

Postural perturbations induced by a moving virtual environment are reduced in persons with brain injury when gripping a mobile object

BACKGROUND AND PURPOSE

Gripping a mobile (unfixed) object increases standing postural stability in healthy individuals. We tested whether the same strategy is effective for stabilizing upright posture perturbed by a moving environment (virtual perturbation) in participants with traumatic brain injury (TBI).

METHODS

Fifteen participants with mild-to-moderate postural deficits after TBI and a comparison group of 15 age-matched healthy subjects participated in the study. Participants stood for 1 minute in front of a large screen with a projected three-dimensional image of a boat; for 30 seconds the boat remained stationary (no visual stimulation condition), and for 30 seconds the boat rocked on the water at a speed of 15°/s (visual stimulation condition). The visual stimulation was applied in pseudorandom order (during either the first or second half of the 1-minute trial). To analyze postural stability, the displacement and velocity of the center of mass in the sagittal and frontal planes were compared between groups and across 4 experimental conditions, including standing with/without visual stimulation and with/without gripping a 300-g object (short wooden stick) in the dominant hand.

RESULTS

Participants with TBI showed greater instability under all experimental conditions. The visual stimulation significantly increased postural oscillations in the sagittal plane by 35% to 63% across groups. Gripping a stick significantly reduced the stimulation-induced instability in the sagittal plane by 19% to 29%, although not to the level of the no-stimulation condition in either group.

CONCLUSION

The stabilizing effect of gripping an external object in participants with TBI was confirmed. A possibility of using this effect as a balance aid strategy requires further investigation.

High-level mobility in chronic traumatic brain injury and its relationship with clinical variables and magnetic resonance imaging findings in the acute phase

OBJECTIVES

To compare high-level mobility in individuals with chronic moderate-to-severe traumatic brain injury (TBI) with matched healthy controls, and to investigate whether clinical variables and magnetic resonance imaging (MRI) findings in the acute phase can predict high-level motor performance in the chronic phase.

DESIGN

A longitudinal follow-up study.

SETTING

A level 1 trauma center.

PARTICIPANTS

Individuals (N=136) with chronic TBI (n=65) and healthy matched peers (n=71).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

High-Level Mobility Assessment Tool (HiMAT) and the revised version of the HiMAT performed at a mean of 2.8 years (range, 1.5-5.4y) after injury.

RESULTS

Participants with chronic TBI had a mean HiMAT score of 42.7 (95% confidence interval [CI], 40.2-45.2) compared with 47.7 (95% CI, 46.1-49.2) in the control group (P<.01). Group differences were also evident using the revised HiMAT (P<.01). Acute-phase clinical variables and MRI findings explained 58.8% of the variance in the HiMAT score (P<.001) and 59.9% in the revised HiMAT score (P<.001). Lower HiMAT scores were associated with female sex (P=.031), higher age at injury (P<.001), motor vehicle collisions (P=.030), and posttraumatic amnesia >7 days (P=.048). There was a tendency toward an association between lower scores and diffuse axonal injury in the brainstem (P=.075).

CONCLUSIONS

High-level mobility was reduced in participants with chronic, either moderate or severe TBI compared with matched peers. Clinical variables in the acute phase were significantly associated with high-level mobility performance in participants with TBI, but the role of early MRI findings needs to be further investigated. The findings of this study suggest that the clinical variables in the acute phase may be useful in predicting high-level mobility outcome in the chronic phase.