Dizziness after traumatic brain injury: Results from an interview study

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).

Self-reported dizziness, balance, and multisensory impairment following mild traumatic brain injury: an exploratory study

Dizziness following mild traumatic brain injury (mTBI), or concussion, is common and can encompass multiple sensations reflecting diverse aetiologies. This exploratory study investigated the types of dizzy sensations experienced, their evolution, and relationship with other post-concussion symptoms. Thirty New Zealanders (24 female) aged 49 ± 16 years who experienced dizziness or imbalance following their injury completed the Dizziness Handicap Inventory, Visual Vertigo Analogue Scale, and the Hospital Anxiety and Depression Scale. Additional custom questionnaires probed subjective experiences of dizziness and balance, headaches, and difficulties with auditory processing and vision. Just over half the participants (56.7%) experienced a single mTBI. The median time interval since the injury was 16 months (IQR = 24 months). Participants usually reported multiple dizzy symptoms which developed within a week of the injury, although delays of up to six months were reported. Most participants (70%) felt their symptoms improved over time, while lack of improvement was associated with a history of multiple mTBI (P = 0.020). Moderate to strong correlations between questionnaire scores representing dizziness handicap, visual vertigo severity, and auditory processing difficulties (P < 0.001) suggest that dizziness and sensory impairment following mTBI are multi-modal and likely to benefit from holistic, multidisciplinary treatment.

Using interpretative phenomenological analysis to probe the lived experiences of persistent postural-perceptual dizziness (PPPD)

BACKGROUND

Persistent Postural-Perceptual Dizziness (PPPD) is a chronic neuro-vestibular condition characterised by subjective dizziness, non-spinning vertigo, and postural imbalance. Symptoms are typically induced by situations of visuo-vestibular conflict and intense visual-motion.

OBJECTIVE

Little research has focused on the lived experiences of people with PPPD. Therefore, our objective was to present an in-depth exploration of patient experiences and sense-making, and the effect of PPPD on psycho-social functioning.

METHODS

We conducted semi-structured interviews with 6 people with PPPD, who were recruited from an Audiovestibular department in Wales. We present a case-by-case Interpretive Phenomenological Analysis (IPA) for each participant and present common themes.

RESULTS

Our analysis revealed a range of superordinate and subordinate themes, individualised to each participant, but broadly described under the following headings: dismissal and non-belief, identity loss, dissociative experiences, poor psychological well-being and processes of sense-making.

CONCLUSION

The qualitative experiences documented in this study will help clinicians and researchers to better understand the lived experiences of PPPD, how PPPD patients make sense of their symptoms, and the psycho-social impacts of the condition.

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.

Health Care Resource Utilization and Costs for Adults With Mild Traumatic Brain Injury With Chronic Vestibular Impairment

OBJECTIVE

To quantify the economic burden of all-cause health care resource utilization (HCRU) among adults with and without chronic vestibular impairment (CVI) after a mild traumatic brain injury (mTBI).

DESIGN

Retrospective matched cohort study.

SETTING

IQVIA Integrated Data Warehouse.

PARTICIPANTS

People with mTBI+CVI (n=20,441) matched on baseline age, sex, year of mTBI event, and Charlson Comorbidity Index (CCI) score to people with mTBI only (n=20,441) (N=40,882).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

All-cause health HCRU and costs at 12 and 24 months post mTBI diagnosis.

RESULTS

People with mTBI+CVI had significantly higher all-cause HCRU and costs at both time points than those with mTBI only. Multivariable regression analysis showed that, when controlling for baseline variables, costs of care were 1.5 times higher for mTBI+CVI than mTBI only.

CONCLUSIONS

People who developed CVI after mTBI had greater overall HCRU and costs for up to 2 years after the injury event compared with people who did not develop CVI after controlling for age, sex, region, and CCI score. Further research on access to follow-up services and effectiveness of interventions to address CVI is warranted.

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.

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.

Relationship Between Cognitive Assessment and Balance Measures in Adolescents Referred for Vestibular Physical Therapy After Concussion

OBJECTIVE

To examine the relationship between cognitive and balance performance in adolescents with concussion.

DESIGN

Retrospective case series.

SETTING

Tertiary.

PATIENTS

Sixty patients.

INTERVENTIONS

Correlation analyses were performed to describe the relationship between symptoms, cognitive measure, and balance measure at the time of initiation of vestibular physical therapy.

MAIN OUTCOME MEASURES

Cognitive performance was assessed using the Immediate Post-concussion Assessment and Cognitive Testing (ImPACT). The dizziness and balance function measures included dizziness severity rating, Activities-specific Balance Confidence scale (ABC), Dizziness Handicap Inventory (DHI), Functional Gait Assessment, gait speed, Timed "UP and GO," Five Times Sit to Stand, and Sensory Organization Test (SOT). To account for multiple comparisons, the False Discovery Rate method was used.

RESULTS

Performance measures of balance were significantly correlated with cognitive measures. Greater total symptom scores were related to greater impairment in the ABC and DHI (r = 0.35-0.39, P ≤ 0.008) and worse performance in condition 2 of the SOT (r = -0.48, P = 0.004). Among the ImPACT composite scores, lower memory scores were correlated with impaired balance performance measures (r = 0.37-0.59, P ≤ 0.012). Lower visual memory was also correlated with worse ABC scores.

CONCLUSIONS

The significant relationships reported between the cognitive performance scores and balance measures may reflect that similar levels of functioning exist across domains in individuals with protracted recovery who receive vestibular physical therapy.

CLINICAL RELEVANCE

The weak-to-moderate relationships warrant the continuous use of multiple domains of assessment. A better understanding to the relationships between the domains of functioning after concussion may improve the overall management approach for adolescents with concussion.

Falls and fallers in traumatic brain injury (TBI) rehabilitation settings: an integrative review

PURPOSE

To critically appraise the research literature on the nature of falls and fallers in traumatic brain injury (TBI) rehabilitation settings.

METHOD

An integrative review of the literature using thematic analysis was undertaken. Papers identified via a systematic search strategy were independently appraised by two reviewers. A data extraction instrument was developed to record results and to aid identification of themes in the literature. Critical Appraisal Skills Programme instruments were utilised to conduct a methodological critique of the papers included.

RESULTS

Thirteen studies were identified as having between 4% and 100% TBI patients in their study cohorts. From these papers, up to 71% of falls took place in a patient's bedroom occurring in peaks and troughs over a 24-h period. With some divergent results, nine themes were identified describing faller characteristics including: (1) functional mobility impairments; (2) dizziness; (3) bladder and bowel dysfunction; (4) certain medications and number of medications prescribed; (5) executive functioning; (6) patient age; (7) fear of falling; (8) coma length following TBI; and (9) Functional Independence Measure (FIM™) total score, subscale scores and particular individual items.

CONCLUSIONS

Being a multifactorial phenomenon, falls are a complex clinical issue. Despite the heterogeneity of diagnosis related groups (DRGs) in the included studies, TBI patients were identified as a high falls risk patient population in several studies. Implications for Rehabilitation Due to multisystem impairments, falls in the traumatic brain injury (TBI) rehabilitation context are a multifactorial and significant clinical issue. When interpreting and generalising results from research into falls, clinicians need to be mindful that falls and faller characteristics may be dependent on study setting and patient population. There is need for context specific research into faller characteristics following a TBI; particularly in relation to post-traumatic amnesia.

Exercise prescription patterns in patients treated with vestibular rehabilitation after concussion

BACKGROUND AND PURPOSE

Individuals with concussion often complain of persistent dizziness and imbalance, and these problems have been treated with vestibular rehabilitation exercises. The purpose of this study is to describe the vestibular rehabilitation exercise prescriptions provided to individuals after concussion.

METHODS

A retrospective chart review of vestibular rehabilitation home exercise programmes prescribed by physical therapists for 104 participants who were diagnosed with concussion was conducted. Each of the exercises was classified by exercise type, duration and frequency. Frequency counts of the most common exercise types were recorded. Exercise progression patterns were examined by determining how exercise types were modified from visit to visit.

RESULTS

Eye-head coordination exercises were the most commonly prescribed exercise type (in 95% of participants), followed by standing static balance exercises (in 88% of participants), and ambulation exercises (in 76% of participants).

CONCLUSIONS

Understanding the prescription patterns of expert clinicians may elucidate the vestibular-related impairments of individuals after concussion and may provide a resource for therapists who may be starting vestibular rehabilitation programmes for management of individuals with concussion. To improve quality of care, future research should be directed to relate outcomes to the exercise prescription patterns.

Associations among self-reported balance problems, post-concussion symptoms and performance-based tests: a longitudinal follow-up study

PURPOSE

The main objectives of this study were to describe long-term self-reported balance problems and to explore their associations with post-concussion symptoms and performance-based tests.

METHOD

Prospective study of patients with mild traumatic brain injury (MTBI). Self-reported balance problems and post-concussion symptoms were measured with the Rivermead Post-concussion Symptoms Questionnaire at 1 and 4 years after injury. Performance-based tests were performed 4 years after injury and included posturography, the Dynamic Gait Index (DGI), walking speed tests, and the six-minute walk test.

RESULTS

Self-reported balance problems were reported in 31% of patients 4 years after injury and correlated significantly with post-concussion symptoms. The correlations with performance-based tests varied from ρ = 0.18 to ρ = 0.70 and were strongest for the maximum walking speed test (ρ = 0.70) and a dual-task test (ρ = 0.43). The DGI had a considerable ceiling effect.

CONCLUSIONS

Balance problems were long-term consequences of MTBI in one third of this study sample. Self-reported balance problems correlated with post-concussion symptoms and some of the performance-based tests. Future research needs to develop and evaluate appropriate rehabilitation strategies that also address the balance problems.

Traumatic brain injury and vestibular pathology as a comorbidity after blast exposure

Blasts or explosions are the most common mechanisms of injury in modern warfare. Traumatic brain injury (TBI) is a frequent consequence of exposure to such attacks. Although the management of orthopedic, integumentary, neurocognitive, and neurobehavioral sequelae in survivors of blasts has been described in the literature, less attention has been paid to the physical therapist examination and care of people with dizziness and blast-induced TBI (BITBI). Dizziness is a common clinical finding in people with BITBI; however, many US military service members who have been exposed to blasts and who are returning from Iraq and Afghanistan also complain of vertigo, gaze instability, motion intolerance, and other symptoms consistent with peripheral vestibular pathology. To date, few studies have addressed such "vestibular" complaints in service members injured by blasts. Given the demonstrated efficacy of treating the signs and symptoms associated with vestibular pathology, vestibular rehabilitation may have important implications for the successful care of service members who have been injured by blasts and who are complaining of vertigo or other symptoms consistent with vestibular pathology. In addition, there is a great need to build consensus on the clinical best practices for the assessment and management of BITBI and blast-related dizziness. The purpose of this review is to summarize the findings of clinicians and scientists conducting research on the effects of blasts with the aims of defining the scope of the problem, describing and characterizing the effects of blasts, reviewing relevant patients' characteristics and sensorimotor deficits associated with BITBI, and suggesting clinical best practices for the rehabilitation of BITBI and blast-related dizziness.