Assessment of impaired self-awareness after moderate-to-severe traumatic brain injury: a comparison of assessment tools.

OBJECTIVE: To compare different assessment methods of impaired self-awareness (ISA). METHODS: We included 37 patients with moderate-to-severe traumatic brain injury (TBI) at a subacute/chronic stage, and 33 healthy controls. ISA was assessed with three methods: discrepancy scores (comparison between patient and proxy ratings) on three scales (Patient Competency Rating Scale (PCRS), Awareness Questionnaire (AQ) and Dysexecutive Questionnaire (DEX)); clinician rating with the Self-Awareness of Deficits Interview (SADI); and the difference between prediction or estimation of performance and actual performance on two cognitive tasks. RESULTS: Clinician-patient discrepancy scores appeared more sensitive than relative-patient discrepancy. The AQ was the most sensitive. The discrepancy scores were strongly correlated one with each other. Correlations with the SADI were weaker. Patients did not overestimate their performance on cognitive tasks, and the prediction did not significantly correlate with other measures of ISA. DISCUSSION/CONCLUSION: Results support the multidimensional nature of ISA: discrepancy scores assess meta-cognitive knowledge (understanding that a function/skill is affected), while the SADI takes into account anticipatory awareness (ability to set realistic goals) and estimation of performance assesses anticipatory and situational awareness. Assessment of these different domains may provide a comprehensive overview of an individual's self-awareness.

Co-existence of depression and post-concussion syndrome one month after mild traumatic brain injury.

BACKGROUND: Previous studies suggest an association between Post-concussion syndrome (PCS) and depression, both highly prevalent after mTBI. OBJECTIVE: To assess the prevalence and risk-factors of depression among patients with PCS 1 month after mTBI. METHODS: We prospectively screened 372 mTBI patients admitted in two academic Emergency Departments between 2017 and 2019. One month after mTBI, we administered the Rivermead Post-concussion symptoms Questionnaire (RPQ) and the Patient Health Questionnaire (PHQ-9) questionnaires over the telephone. PCS and depression were defined by RPQ ≥ 12 and PHQ-9 ≥ 10. Multivariate multinomial regression identified baseline factors associated with PCS and depression. RESULTS: Two hundred and eight completed RPQ and PHQ-9. Forty-seven patients (22.5%) met criteria for PCS, among which 22 (46.8%) met criteria for depression (PCS+D+). Patients with PCS but without depression were less likely to present with an associated injury (Coefficient = -1.6, p = 0.047) and to report initial sadness (Coefficient = -2.5, p = 0.03). Initial sadness (Coefficient = -1.3, p = 0.047), associated injury (Coefficient = -1.9, p = 0.008), as well as initial nausea (Coefficient = -1.8, p = 0.002), and male sex (Coefficient = 1.8, p = 0.002), were associated with the absence of depression and PCS in comparison with PCS+D+ patients. CONCLUSION: Among patients with PCS 1 month after mTBI, those with depression are more likely to present with initial sadness and with an associated injury.

Rehabilitation of working memory after acquired brain injury and multiple sclerosis: A systematic review.

The objective is to study the effectiveness of working memory (WM) rehabilitation after Acquired brain injury (ABI) and multiple sclerosis (MS). A systematic database search of published studies, following PRISMA recommendations, with assessment of methodological quality and risk of bias, was conducted. The results were analysed according to the rehabilitation method used. 31 studies (including 14 class I) were included, and 11 different training programs were identified. Despite great variability in training methodology and outcome measures, the results were positive overall. However, only three rehabilitation programs showed a transfer effect to WM (near) and daily life with long-term maintenance. The results were more variable for protocols limited to the use of computerized n-back training tasks. Overall, the current evidence supports multi-task WM training rather than single-task-limited program. It also supports early and long duration training, with some therapist support. However, it is not possible, to date, to make strong recommendations regarding the rehabilitation program to be used preferentially. Although results are encouraging, level of evidence remains modest, particularly regarding the maintenance of the therapeutic effect after the end of training, and the transfer to everyday life skills. The influence of rehabilitation parameters (training duration, therapist involvement … ) remains difficult to assess.

The 20-item dysexecutive questionnaire after severe traumatic brain injury: Distribution of the total score and its significance.

TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01437683..

Discriminative value of different combinations of tests to detect unilateral neglect in patients with right hemisphere damage.

BACKGROUND AND PURPOSE: This study was undertaken to assess the most sensitive combination of tests to detect peripersonal unilateral neglect (UN) after stroke. METHODS: The present study is a secondary analysis of a previously reported multicentric study of 203 individuals with right hemisphere damage (RHD), mainly subacute stroke, 11 weeks postonset on average, and 307 healthy controls. A battery of seven tests, providing 19 age- and education-adjusted z-scores, were given: the bells test, line bisection, figure copying, clock drawing, overlapping figures test, and reading and writing. Statistical analyses used a logistic regression and a receiver operating characteristic (ROC) curve after adjustment on demographic variables. RESULTS: A combination of four z-scores based on the following three tests provided good discrimination of patients with RHD from matched healthy controls: the starting point and the difference between the number of omissions on left and right sides from the bells test, rightward deviation in bisection of long lines (20 cm), and left-sided omissions in a reading task. The area under the ROC curve was 0.865 (95% confidence interval = 0.83-0.901), with sensitivity = 0.68, specificity = 0.95, accuracy = 0.85, positive predictive value = 0.90, and negative predictive value = 0.82. CONCLUSIONS: The most sensitive and parsimonious combination of tests to detect UN after stroke relies on four scores from three simple tests (bells test, line bisection, and reading). Future study is warranted to assess its ability to account for the functional difficulties of UN in daily life in the patient's actual environment.

Rehabilitation and outcomes after complicated vs uncomplicated mild TBI: results from the CENTER-TBI study.

BACKGROUND: Despite existing guidelines for managing mild traumatic brain injury (mTBI), evidence-based treatments are still scarce and large-scale studies on the provision and impact of specific rehabilitation services are needed. This study aimed to describe the provision of rehabilitation to patients after complicated and uncomplicated mTBI and investigate factors associated with functional outcome, symptom burden, and TBI-specific health-related quality of life (HRQOL) up to six months after injury. METHODS: Patients (n = 1379) with mTBI from the Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI) study who reported whether they received rehabilitation services during the first six months post-injury and who participated in outcome assessments were included. Functional outcome was measured with the Glasgow Outcome Scale - Extended (GOSE), symptom burden with the Rivermead Post Concussion Symptoms Questionnaire (RPQ), and HRQOL with the Quality of Life after Brain Injury - Overall Scale (QOLIBRI-OS). We examined whether transition of care (TOC) pathways, receiving rehabilitation services, sociodemographic (incl. geographic), premorbid, and injury-related factors were associated with outcomes using regression models. For easy comparison, we estimated ordinal regression models for all outcomes where the scores were classified based on quantiles. RESULTS: Overall, 43% of patients with complicated and 20% with uncomplicated mTBI reported receiving rehabilitation services, primarily in physical and cognitive domains. Patients with complicated mTBI had lower functional level, higher symptom burden, and lower HRQOL compared to uncomplicated mTBI. Rehabilitation services at three or six months and a higher number of TOC were associated with unfavorable outcomes in all models, in addition to pre-morbid psychiatric problems. Being male and having more than 13 years of education was associated with more favorable outcomes. Sustaining major trauma was associated with unfavorable GOSE outcome, whereas living in Southern and Eastern European regions was associated with lower HRQOL. CONCLUSIONS: Patients with complicated mTBI reported more unfavorable outcomes and received rehabilitation services more frequently. Receiving rehabilitation services and higher number of care transitions were indicators of injury severity and associated with unfavorable outcomes. The findings should be interpreted carefully and validated in future studies as we applied a novel analytic approach. TRIAL REGISTRATION: ClinicalTrials.gov NCT02210221.

Atropine-induced toxicity after off-label sublingual administration of eyedrop for sialorrhoea treatment in neurological disabled patients.

Sialorrhea is a troublesome and disabling symptom defined by the unintentional loss of saliva from the mouth, usually associated with swallowing disorders. Today there is no consensus about the management of sialorrhoea, but off-label use of ophthalmic atropine eyedrop administered sublingually may offer benefits, despite limited safety data. We report 2 cases of atropine overdose after sublingual administration illustrating that atropine can expose to severe adverse effects when administered sublingually. The noncompartmental pharmacokinetic study of atropine performed in 1 patient highlighted that systemic absorption of sublingual atropine was effective (Cmax [1 h] = 2.2 ng mL-1 ; approximately) after a single dose of 1 mg.

Age-Related Changes in the Association Between Traumatic Brain Injury and Dementia in Older Men and Women.

OBJECTIVE: To investigate age-related changes in the association between traumatic brain injury (TBI) and dementia in older men and women separately. SETTING: A total of 243 general practices in the UK. PARTICIPANTS: This study included 4760 patients who received a first TBI diagnosis between 1995 and 2010 (index date), and 4760 patients without TBI who were matched to those with TBI by age, sex, index year, Charlson Comorbidity Index, alcohol dependence, and physician (index date: a randomly selected visit date). DESIGN: Retrospective cohort study. MAIN MEASURES: Incidence of dementia in the decade following index date. RESULTS: Within 10 years of index date, 8.8% of men with TBI and 4.8% of those without TBI were diagnosed with dementia, while the respective figures were 9.0% and 6.7% in women (P values < .01). There was a significant association between TBI and dementia in men (hazard ratio [HR] = 2.29, 95% confidence interval [CI]: 1.64-3.19) and in women (HR = 1.33, 95% CI: 1.07-1.64). Furthermore, the association between TBI and dementia was significant in men aged 60 to 70 (HR = 2.51, 95% CI: 1.27-4.96) and 71 to 80 years (HR = 3.00, 95% CI: 1.82-4.93), whereas the relationship was only significant and potentially unreliable in women aged 81 to 90 years (HR = 1.49, 95% CI: 1.03-2.14). CONCLUSIONS: The age-related relationship between TBI and dementia differed between men and women. More research of a prospective nature and including behavioral data is needed to better understand these differences.

Relationships between neuropsychological impairments and functional outcome eight years after severe traumatic brain injury: Results from the PariS-TBI study.

BACKGROUND/OBJECTIVES: The objective was to assess the relationships between neuropsychological impairments, functional outcome and life satisfaction in a longitudinal study of patients after a severe traumatic brain injury (TBI) (PariS-TBI study). PATIENTS: Out of 243 survivors, 86 were evaluated 8 years post-injury. They did not significantly differ from patients lost-to-follow up except for the latter being more frequently students or unemployed before the injury. METHODS: Outcome measures included the Glasgow Outcome Scale-Extended (GOS-E), a functional independence questionnaire, employment, mood, fatigue and satisfaction with life. Neuropsychological outcome was assessed by two ways: performance-based outcome measures, using neuropsychological tests and patient and relative-based measures. RESULTS: Neuropsychological measures were not significantly related to initial injury severity nor to gender, but were significantly related to age and education. After statistical correction for multiple comparisons, cognitive testing and cognitive questionnaires were significantly correlated with most outcome measures. By contrast, satisfaction with life was only related with patient-rated questionnaires. A regression analysis showed that the Trail-Making-Test-A was the best predictor of functional outcome, in addition to education duration. CONCLUSIONS: Cognitive measures, particularly slowed information processing speed, were significant indicators of functional outcome at a long-term post-injury, beyond and above demographics or injury severity measures.

Impact of Combined Transcranial Direct Current Stimulation and Speech-language Therapy on Spontaneous Speech in Aphasia: A Randomized Controlled Double-blind Study.

OBJECTIVE: Aphasia recovery depends on neural reorganization, which can be enhanced by speech-language therapy and noninvasive brain stimulation. Several studies suggested that transcranial direct current stimulation (tDCS) associated with speech-language therapy may improve verbal performance evaluated by analytic tests, but none focused on spontaneous speech. We explored the effect of bihemispheric tDCS on spontaneous speech in patients with poststroke aphasia. METHODS: In this multicentric controlled randomized cross-over double-blind study, we included 10 patients with poststroke aphasia (4 had aphasia >6 months and 6 with aphasia <6 months). We combined the sessions of speech-language therapy and bihemispheric tDCS (2 mA, 20 min). After three baseline speech evaluations (1/week), two different conditions were randomly consecutively proposed: active and sham tDCS over 3 weeks with 1 week of washout in between. The main outcome measure was the number of different nouns used in 2 min to answer the question "what is your job." RESULTS: There was no significant difference between conditions concerning the main outcome measure (p = .47) nor in the number of verbs, adjectives, adverbs, pronouns, repetitions, blank ideas, ideas, utterances with grammatical errors or paraphasias used. Other cognitive functions (verbal working memory, neglect, or verbal fluency) were not significantly improved in the tDCS group. No adverse events occurred. CONCLUSION: Our results differed from previous studies using tDCS to improve naming in patients with poststroke aphasia possibly due to bihemispheric stimulation, rarely used previously. The duration of the rehabilitation period was short given the linguistic complexity of the measure. This negative result should be confirmed by larger studies with ecological measures.

Blue-Enriched White Light Therapy Reduces Fatigue in Survivors of Severe Traumatic Brain Injury: A Randomized Controlled Trial.

OBJECTIVE: Fatigue is one of the disabling sequelae of traumatic brain injury (TBI), with repercussions on quality of life, rehabilitation, and professional reintegration. Research is needed on effective interventions. We evaluated efficacy of blue-enriched white light (BWL) therapy on fatigue of patients with severe TBI. SETTING: Physical Medicine and Rehabilitation and Physiology departments of University hospitals. PARTICIPANTS: Adult patients with fatigue symptoms following severe TBI, Fatigue Severity Scale (FSS) score 4 or more, Epworth Sleepiness Scale (ESS) score 10 or more, and/or Pittsburgh Sleep Quality Index (PSQI]) more than 5 were randomly assigned to one of 2 parallel groups: a BWL therapy group, with 30-minute exposure to waking white light enriched with blue for 4 weeks, and a group without light therapy (N-BWL), no light. DESIGN: Randomized controlled trial. ClinicalTrials.gov number: NCT02420275. MAIN MEASURES: The primary outcome measure was the response of the FSS to 4 weeks of treatment. In addition, we assessed latency change of the P300 component of event-related potentials before and after therapy. RESULTS: Significant improvement in the FSS score (P = .026) was found in the BWL group compared with the N-BWL group. CONCLUSION: BWL phototherapy reduces fatigue in patients with severe TBI.

Social cognition and traumatic brain injury: current knowledge.

The notion of social cognition is an umbrella term which refers to a set of processes which permit the perception of social cues from the self and others, the interpretation and understanding of own and other's emotions, beliefs and behaviors, and the generation of responses to these inferences to guide social behavior. This paper is an introduction to our special issue of Brain Injury devoted to the study of social cognition after traumatic brain injury.

Treatment of social cognition impairments in patients with traumatic brain injury: a critical review.

Objective: The aim of this study is to review published research on treatment of social cognition impairments in patients with traumatic brain injury (TBI).Methods: Following the PRISMA guidelines, a PubMed literature search was conducted, followed by a manual search in recently published papers. Main criteria for selection were that patients had sustained a TBI, and that social cognition was the main target of treatment. A total of 16 papers and three reviews were selected and included in the present review.Results: Five studies (including three randomized controlled trials (RCT)) addressed facial affect recognition, one study specifically addressed emotional prosody, two RCTs used a combination of treatment strategies addressing social perception deficits. Six studies, including two RCTs, addressed social communication skills or theory of mind. Finally, two RCTs reported the effectiveness of a more global approach, addressing multiple domains of social cognition, such as emotion perception, social skills training, and theory of mind.Discussion/conclusion: Although there has been much less research on treatment of social cognition in patients with TBI as compared with psychiatric conditions, the findings reported in the present review are encouraging. Further multicenter large-scale RCTs are needed, with special emphasis on the generalization of treatment effects to social skills in everyday life.

Practitioners' opinions on traumatic brain injury care pathways in Finland and France: different organizations, common issues.

OBJECTIVE: In traumatic brain injury (TBI), differences in health-care contexts have profound effects on care pathways. Objectives were to compare TBI pathways of care and practitioners' views on quality of care issues in two large European areas: Varsinais-Suomi, Finland and Ile-de-France, France. METHODS: Thematic analysis of semi-structured interviews was conducted with TBI practitioners (n = 10) from all stages of TBI care. Interviews addressed organization and financing of care, decision-making on care transitions, and perceived issues. The structure-process-outcome model of Donabedian was used to classify findings related to quality of care issues. RESULTS: Main differences in organization of care pathways for people with TBI were related to financing modalities, number of pathway alternatives, inpatient versus outpatient rehabilitation, and indirect versus direct referrals to rehabilitation. Similar categories of issues were raised in the two settings. Issues in structures involved availability of services, financial access, and heterogeneity of expertise. Issues in processes involved diagnosis and follow-up, training regarding cognitive impairments, decision-making for referrals, transition delays, and care pathways of very severely affected patients. CONCLUSIONS: These findings provide clues to address care pathways in further comparative studies. Determinants of care pathway quality could be classified as direct or indirect, binding or adaptive organizational factors.

Psychometric properties of the French version of the Rating Scale of Attentional Behaviour.

The Rating Scale of Attentional Behaviour (RSAB) was devised by Ponsford and Kinsella to assess the impact of attentional impairments on everyday behaviour. The scale includes 14 items. The objective of this study was to assess the psychometric properties of a French translation of the RSAB. A sample of 196 healthy participants and 27 patients with chronic acquired brain injury was included. For healthy participants, both self and a relative's ratings were independently recorded. For the patients, a therapist's rating was obtained in addition. The scale showed good internal consistency. A mild significant effect of education duration was found in the healthy control group. Principal component analysis in healthy participants (self-assessment) yielded three underlying factors accounting for 58.2% of the variance. The scale was able to adequately discriminate patients from healthy controls. The area under the ROC curve was 0.76 both for self- and proxy ratings. In the patient group, the item related to fatigue was the one that obtained the highest ranking. RSAB ratings were poorly related to neuropsychological testing, but proxy ratings were significantly correlated with other questionnaires assessing cognitive failures, mood and fatigue.

Subjective complaints after acquired brain injury: presentation of the Brain Injury Complaint Questionnaire (BICoQ).

The objective of the present study was to present a new complaint questionnaire designed to assess a wide range of difficulties commonly reported by patients with acquired brain injury. Patients (n = 619) had been referred to a community re-entry service at a chronic stage after brain injury, mainly traumatic brain injury (TBI). The Brain Injury Complaint Questionnaire (BICoQ) includes 25 questions in the following domains: cognition, behavior, fatigue and sleep, mood, and somatic problems. A self and a proxy questionnaire were given. An additional question was given to the relative, about the patient's awareness of his difficulties. The questionnaires had a good internal coherence, as measured with Cronbach's alpha. The most frequent complaints were, in decreasing order, mental slowness, memory troubles, fatigue, concentration difficulties, anxiety, and dual tasking problems. Principal component analysis with varimax rotation yielded six underlying factors explaining 50.5% of total variance: somatic concerns, cognition, and lack of drive, lack of control, psycholinguistic disorders, mood, and mental fatigue/slowness. About 52% of patients reported fewer complaints than their proxy, suggesting lack of awareness. The total complaint scores were not significantly correlated with any injury severity measure, but were significantly correlated with disability and poorer quality of life (Note: only factor 2 [cognition/lack of drive] was significantly related to disability.) The BICoQ is a simple scale that can be used in addition to traditional clinical and cognitive assessment measures, and to assess awareness of everyday life problems.

Self-awareness four years after severe traumatic brain injury: discordance between the patient's and relative's complaints. Results from the PariS-TBI study.

OBJECTIVE: To evaluate the patient's awareness of his or her difficulties in the chronic phase of severe traumatic brain injury (TBI) and to determine the factors related to poor awareness. DESIGN/SETTING/SUBJECTS: This study was part of a larger prospective inception cohort study of patients with severe TBI in the Parisian region (PariS-TBI study). Intervention/Main measures: Evaluation was carried out at four years and included the Brain Injury Complaint Questionnaire (BICoQ) completed by the patient and his or her relative as well as the evaluation of impairments, disability and quality of life. RESULTS: A total of 90 patient-relative pairs were included. Lack of awareness was measured using the unawareness index that corresponded to the number of discordant results between the patient and relative in the direction of under evaluation of difficulties by the patient. The only significant relationship found with lack of awareness was the subjective burden perceived by the relative (Zarit Burden Inventory) ( r = 0.5; P < 0.00001). There was no significant relationship between lack of awareness and injury severity, pre-injury socio-demographic data, cognitive impairments, mood disorders, functional independence (Barthel index), global disability (Glasgow Outcome Scale), return to work at four years or quality of life (Quality Of Life after Brain Injury scale (QOLIBRI)). CONCLUSION: Lack of awareness four years post severe TBI was not related to the severity of the initial trauma, sociodemographic data, the severity of impairments, limitations of activity and participation, or the patient's quality of life. However, poor awareness did significantly influence the weight of the burden perceived by the relative.

Impact of extended monitoring-guided intensive care on outcome after severe traumatic brain injury: A prospective multicentre cohort study (PariS-TBI study).

OBJECTIVE: We evaluated whether an integrated monitoring with systemic and specific monitoring affect mortality and disability in adults with severe traumatic brain injury (sTBI). METHODS: Adults with severeTBI (Glasgow Coma Scale [GCS] ≤ 8) admitted alive in intensive care units (ICUs) were prospectively included. Primary endpoints were in-hospital 30-day mortality and extended Glasgow outcome score (GOSE) at 3 years. Association with the intensity of monitoring and outcome was studied by comparing a high level of monitoring (HLM) (systemic and ≥3 specific monitoring) and low level of monitoring (LLM) (systemic and 0-2 specific monitoring) and using inverse probability weighting procedure. RESULTS: 476 patients were included and IPW was used to improve the balance between the two groups of treatments (HLM/LMM). Overall hospital mortality (at 30 days) was 43%, being significantly lower in HLM than LLM group (27% vs. 53%: RR, 1.63: 95% CI: 1.23-2.15). The 14-day hospital mortality was also lower in the HLM group than expected, based upon the CRASH prediction model (35%). At 3 years, disability was not significantly different between the monitoring groups. CONCLUSIONS: After adjustment, HLM group improved short-term mortality but did not show any improvement in the 3-year outcome compared with LLM.

Objective and Subjective Burden of Informal Caregivers 4 Years After a Severe Traumatic Brain Injury: Results From the PariS-TBI Study.

OBJECTIVE: Prospective assessment of informal caregiver (IC) burden 4 years after the traumatic brain injury of a relative. SETTING: Longitudinal cohort study (metropolitan Paris, France). PARTICIPANTS: Home dwelling adults (N = 98) with initially severe traumatic brain injury and their primary ICs. MAIN OUTCOME MEASURES: Informal caregiver objective burden (Resource Utilization in Dementia measuring Informal Care Time [ICT]), subjective burden (Zarit Burden Inventory), monetary self-valuation of ICT (Willingness-to-pay, Willingness-to-accept). RESULTS: Informal caregivers were women (81%) assisting men (80%) of mean age of 37 years. Fifty-five ICs reported no objective burden (ICT = 0) and no/low subjective burden (average Zarit Burden Inventory = 12.1). Forty-three ICs reported a major objective burden (average ICT = 5.6 h/d) and a moderate/severe subjective burden (average Zarit Burden Inventory = 30.3). In multivariate analyses, higher objective burden was associated with poorer Glasgow Outcome Scale-Extended scores, with more severe cognitive disorders (Neurobehavioral Rating Scale-revised) and with no coresidency status; higher subjective burden was associated with poorer Glasgow Outcome Scale-Extended scores, more Neurobehavioral Rating Scale-revised disorders, drug-alcohol abuse, and involvement in litigation. Economic valuation showed that on average, ICs did not value their ICT as free and preferred to pay a mean Willingness-to-pay = &OV0556;17 per hour to be replaced instead of being paid for providing care themselves (Willingness-to-accept = &OV0556;12). CONCLUSION: Four years after a severe traumatic brain injury, 44% of ICs experienced a heavy multidimensional burden.

Loss to Follow-Up and Social Background in an Inception Cohort of Patients With Severe Traumatic Brain Injury: Results From the PariS-TBI Study.

OBJECTIVES: To assess determinants of loss to follow-up (FU) at 2 time points of an inception traumatic brain injury (TBI) cohort. DESIGN AND PARTICIPANTS: The PariS-TBI study consecutively included 504 adults with severe TBI on the accident scene (76% male, mean age 42 years, mean Glasgow Coma Scale 5). No exclusion criteria were used. MAIN MEASURE: Loss to FU at 1 and 4 years was defined among survivors as having no outcome data other than survival status. RESULTS: Among 257 1-year survivors, 118 (47%) were lost to FU at 1 year and 98 (40%) at 4 years. Main reasons for loss to FU were impossibility to achieve contact (109 at 1 year, 52 at 4 years) and refusal to participate (respectively 5 and 24). At 1 year, individuals not working preinjury or with nonaccidental traumas were more often lost to FU in univariate and multivariable analyses. At 4 years, loss to FU was significantly associated with preinjury alcohol abuse and unemployment. Relationship with injury severity was not significant. CONCLUSIONS: Socially disadvantaged persons are underrepresented in TBI outcome research. It could result in overestimation of outcome and biased estimates of sociodemographic characteristics' effects. These persons, particularly unemployed individuals, require special attention in clinical practice.