Safety and efficacy of blood flow restriction exercise in individuals with neurological disorders: A systematic review.

OBJECTIVES: This systematic review evaluated the safety and efficacy of blood flow restriction exercise (BFRE) on skeletal muscle size, strength, and functional performance in individuals with neurological disorders (ND). METHODS: A literature search was performed in PubMed, CINAHL, and Embase. Two researchers independently assessed eligibility and performed data extraction and quality assessments. ELIGIBILITY CRITERIA: Study populations with ND, BFRE as intervention modality, outcome measures related to safety or efficacy. RESULTS: Out of 443 studies identified, 16 were deemed eligible for review. Three studies examined the efficacy and safety of BFRE, one study focused on efficacy results, and 12 studies investigated safety. Disease populations included spinal cord injury (SCI), inclusion body myositis (sIBM), multiple sclerosis (MS), Parkinson's disease (PD), and stroke. A moderate-to-high risk of bias was presented in the quality assessment. Five studies reported safety concerns, including acutely elevated pain and rating of perceived exertion levels, severe fatigue, muscle soreness, and cases of autonomic dysreflexia. Two RCTs reported a significant between-group difference in physical function outcomes, and two RCTs reported neuromuscular adaptations. CONCLUSION: BFRE seems to be a potentially safe and effective training modality in individuals with ND. However, the results should be interpreted cautiously due to limited quality and number of studies, small sample sizes, and a general lack of heterogeneity within and between the examined patient cohorts.

Screening for treatment-required sleep apnoea in patients with spinal cord injury within one year after injury in a rehabilitation setting.

PURPOSE: The current study aims to assess the efficacy of the Stop-Bang Questionnaire (SBQ) in screening treatment-required sleep apnoea following Spinal Cord Injury (SCI). Additionally, we explore the performance of combined questionnaires and pulse oximetry to determine the most cost-effective method. METHODS: The study employs a cross-sectional observational design. All patients admitted to in-hospital rehabilitation at the Spinal Cord Injury Centre of Western Denmark from September 2022 to February 2023 were continuously enrolled. Participating patients underwent SBQ screening, a standard sleep questionnaire, and cardiorespiratory monitoring, followed by an individual consultation with a physician. RESULTS: During the study period, 35 SCI patients were admitted, with 24 providing informed consent. Among the 24 included patients, there was a 75% prevalence of mild to severe sleep apnoea, and 46% had treatment-required sleep apnoea. The SBQ missed only one patient with treatment-required sleep apnoea but misclassified eight patients. Combining SBQ with the pulse oximetry demonstrated the best performance in identifying patients with sleep apnoea. CONCLUSION: The study indicates that SBQ alone is insufficient for screening treatment-required sleep apnoea. Exploratory analysis suggests that combining SBQ with a simple pulse oximetry measurement might enhance accuracy.

Convergence insufficiency in patients with post-concussion syndrome is accompanied by a higher symptom load: a cross-sectional study.

OBJECTIVE: To estimate the prevalence of convergence insufficiency (CI) in adult patients with post-concussion syndrome and determine the impact of CI on symptom load. METHODS: Cross-sectional study of 103 patients with neurological symptoms 2-6 months after a concussion. Symptoms were assessed with the Rivermead Post Concussion Symptoms Questionnaire (RPQ), and CI was diagnosed using near point of convergence, vergence facility, and the Convergence Insufficiency Symptom Survey. The RPQ score for patients with and without CI was compared, and sensitivity, specificity, and area under the receiver operating characteristic curve for the two visually related RPQ questions as indicators of CI were calculated. RESULTS: The proportion of patients diagnosed with symptomatic CI was 20.4% (95% confidence interval: 13.1-29.5%). The RPQ score was significantly higher for patients with symptomatic CI both before (p = .01) and after removal of the two visually related questions in the RPQ-questionnaire (p = .03). The two visually related RPQ questions were unable to detect CI. CONCLUSION: In patients with post-concussion syndrome, the load of nonvisual symptoms is higher in the presence of CI. A prospective interventional study on CI is required to study the relationship between CI and other post-concussion symptoms.

Occurrence, presence and severity of bruxism and its association with altered state of consciousness in individuals with severe acquired brain injury.

BACKGROUND: Excessive jaw muscle activity is a frequent complication after acquired brain injury (ABI). OBJECTIVE: The study aimed to identify the occurrence and severity of jaw muscle activity and its association with altered state of consciousness in patients with ABI. METHODS: A total of 14 severe ABI patients with varied altered state of consciousness were recruited. A single-channel electromyographic (EMG) device was used to assess the jaw muscle activity for three consecutive nights during Week 1 and Week 4 following admission. Differences in number of EMG episodes/h between Week 1 and 4 were analysed using non-parametric tests and association between the EMG activity and altered state of consciousness were analysed using Spearman's correlation test. RESULTS: Nine of fourteen (64%) patients showed indications of bruxism (cutoff: >15 EMG episodes/h). The average EMG episodes/h at admission were 44.5 ± 13.6 with no significant changes after Week 4 of admission (43 ± 12.9; p = .917). The EMG episodes/h ranged from 2 to 184 during Week 1 and 4-154 during Week 4. There were no significant correlations between the number of EMG episodes/h during the three nights and the individuals altered state of consciousness during Week 1 and Week 4. CONCLUSION: Patients with ABI had a conspicuously high but variable level of jaw muscle activity at admission and it tend to remain high after 4 week of hospitalisation which could potentially lead to adverse effects such as excessive tooth wear, headaches and pain in jaw muscles. The lack of associations between individuals altered level of consciousness and EMG activity could be due to low sample size and further studies are clearly warranted in this patient group with special needs. Single-channel EMG devices can record jaw muscle activity early in the hospitalisation period and might be a helpful tools for early detection of bruxism in ABI patients.

Estimating Day-to-Day Circadian Rhythm in Patients with Severe Acquired Brain Injury at the Beginning of In-Hospital Rehabilitation.

BACKGROUND: Patients with severe acquired brain injury (sABI) are likely to have a disturbed circadian rhythm in the early phase of neurorehabilitation. Circadian rhythm and sleep play an important role in the rehabilitation of patients with severe acquired brain injury (sABI). Research has also pointed out the importance of investigating novel ways of assessing sleep and circadian rhythm in patients with acquired brain injury. Established methods fail to apply to the heterogeneous and fluctuant biological or behavioral signals of the patients with sABI. Accelerometry (ACC) has proven a useful measure of circadian rhythm in sABI patients. However, ACC is unavailing if patients have limited motor activity due to a low consciousness level or severe paresis. Heart rate (HR) could be a viable alternative. In this study, we aim to present a novel model for the estimation of circadian rhythm and rhythm characteristics in both motor-active and -inactive patients using ACC and HR. Furthermore, we aim to present the results of the model in patients with sABI during their first three weeks of subacute in-hospital neurorehabilitation. METHODS: An explorative observational study. Continuous recordings of ACC and electrocardiography were conducted. The suggested model was applied to examine circadian rhythms. RESULTS: This study has proven the feasibility of a novel model for the analysis of circadian rhythm. Twenty-nine patients were included, 20 motor active and nine motor inactive. Estimates of rhythm characteristics have been presented along with estimates of circadian rhythm presence or absence for both groups. CONCLUSIONS: The model has been successfully applied in a population of patients with sABI. The circadian rhythm of patients undergoing in-hospital neurorehabilitation is fluctuating across time and highly variant between subjects within the first three weeks after admission to sub-acute neurorehabilitation.

Blood flow restriction exercise of the tibialis anterior in people with stroke: a preliminary study.

BACKGROUND: Blood flow restriction exercise (BFR-E) could be a useful training adjunct for patients with weakness after stroke to augment the effects of exercise on muscle activity. We aimed to examine neurophysiological changes (primary aim) and assess patient perceptions (secondary aim) following BFR-E. METHODS: Fourteen participants with stroke performed BFR-E (1 session) and exercise without blood flow restrictsion (Exercise only) (1 session), on two days, ≈7 days apart. In each session, two sets of tibialis anterior (TA) contractions were performed and electromyography (EMG) was recorded. Eight participants underwent transcranial magnetic stimulation (single-pulse stimulation, short interval intracortical inhibition (SICI), intracortical facilitation (ICF)) and peripheral electrical stimulation (maximal peak-to-peak M-wave (M-max)) of the TA before, immediately-after, 10-min-after and 20-min-after BFR-E and Exercise only. Numerical rating scores (NRS) for pain, discomfort, fatigue, safety, focus and difficulty were collected for all subjects (n = 14). Paired comparisons and linear mixed models assessed the effects of BFR-E and Exercise only. RESULTS: No adverse events due to exercise were reported. There was no contraction-number × condition interaction for EMG amplitude during exercise (p = 0.15), or time × condition interaction for single-pulse stmulation, SICI, ICF or M-max amplitude (p = 0.34 to p = 0.97). There was no difference between BFR-E and Exercise only in NRS scores (p = 0.10 to p = 0.50). CONCLUSION: Using our training paradigm, neurophysiological parameters, feasibility, tolerability and perceptions of safety were not different between BFR-E and Exercise only. As participants were generally well-functioning, our results are not generalizable to lower functioning people with stroke, different (more intense) exercise protocols or longer term training over weeks or months.

Evaluation of rest-activity cycles in patients with severe acquired brain injury: an observational study.

BACKGROUND: There is little knowledge about rest-activity cycles (RAC) in patients with severe-acquired brain injury (sABI) during early in-hospital rehabilitation. This study aimed to investigate if patients with sABI displayed unconsolidated RACs at the beginning of in-hospital rehabilitation, and how these changed over time. METHODS: This study was a prospective observational study. All patients consecutively admitted to one ward were screened for eligibility. We recorded accelerometric activity for 20 days. The Daytime Activity Ratio (DAR) of activity between daytime (7-22) and the total activity during the entire day was calculated and used to estimate consolidation. RESULTS: Fifty-five patients were screened and 20 patients were included. Complete day 1 & 2 data was obtained on 18 patients. Fifty-six percentage of these had a consolidated RAC at the beginning of rehabilitation. On day 19 & 20, complete data could be obtained from 15 patients, 80% of these had consolidation of RAC. When comparing these a significant mean increase of 5.8% 95%CI(0.52; 11.01) in DAR was found p < .05, and the model of all data also showed a significant increase in median DAR over time p < .01. CONCLUSION: RAC consolidation improves over time in patients admitted for in-hospital early neurorehabilitation.

Developing and validating an accelerometer-based algorithm with machine learning to classify physical activity after acquired brain injury.

Purpose: To develop and validate an accelerometer-based algorithm classifying physical activity in people with acquired brain injury (ABI) in a laboratory setting resembling a real home environment.Materials and methods: A development and validation study was performed. Eleven healthy participants and 25 patients with ABI performed a protocol of transfers and ambulating activities. Activity measurements were performed with accelerometers and with thermal video camera as gold standard reference. A machine learning-based algorithm classifying specific physical activities from the accelerometer data was developed and cross-validated in a training sample of 11 healthy participants. Criterion validity of the algorithm was established in 3 models classifying the same protocol of activities in people with ABI.Results: Modeled on data from 11 healthy and 15 participants with ABI, the algorithm had a good precision for classifying transfers and ambulating activities in data from 10 participants with ABI. The weighted sensitivity for all activities was 89.3% (88.3-90.4%) and the weighted positive predictive value was 89.7% (88.7-90.7%). The algorithm differentiated between lying and sitting activities.Conclusion: An algorithm to classify physical activities in populations with ABI was developed and its criterion validity established. Further testing of precision in home settings with continuous activity monitoring is warranted.

Prediction of Upper Limb use Three Months after Stroke: A Prospective Longitudinal Study.

BACKGROUND: A major goal of upper limb (UL) rehabilitation after stroke is to facilitate the use of the paretic arm in daily life activities. PURPOSE: To examine if UL impairment two weeks after stroke can predict real-life UL use at three months. Furthermore, to identify additional factors which contribute to future UL use, and characteristics of patients who do not achieve normal UL use. METHODS: This study included patients with stroke ≥ 18 years. UL impairment was assessed by Fugl-Meyer upper extremity motor assessment (FM). Use ratio between affected and unaffected UL was assessed with accelerometers at three months after stroke. The association between FM score and UL use ratio was investigated with linear regression models and adjusted for secondary variables. Non-normal use was examined by a logistic regression. RESULTS: Eighty-seven patients were included. FM score two weeks after stroke predicted 38% of the variance in UL use ratio three months after stroke. A multivariate regression model predicted 55%, and the significant predictors were FM, motor-evoked potential (MEP) status, and neglect. Non-normal use could be predicted with a high accuracy based on MEP and/or neglect. In a logistic regression sensitivity for prediction of non-normal use was 0.93 and specificity was 0.75. CONCLUSION: Better baseline capacity of the paretic UL predicted increased use of the arm and hand in daily life. Non-normal UL use could be predicted reliably based on the absence of MEPs and/or presence of neglect.

Construct and content validity of the Functional Oral Intake Scale; Analyses from a cohort of patients with acquired brain injury.

OBJECTIVE: To investigate the construct validity of the Functional Oral Intake Scale (FOIS) as a proxy measure for dysphagia, through associations with swallowing prerequisites, orofacial functions, age, and diagnosis; and to investigate content validity through distributions of FOIS ratings. METHODS: A cohort of 1,876 patients with severe acquired brain injury. Early Functional Abilities items were applied as measures of swallowing prerequisites and orofacial functions. Clustered logistic regression model with 6,052 cross-sectional observations. RESULTS: Disturbance in swallowing 10.55 OR (95%CI:7.90;14.09), oro-facial stimulation 3.04 OR (95%CI:2.41;3.83), and head control 2.86 OR (95%CI:2.25;3.62) were robustly associated with tube feeding (FOIS 1-3). Disturbance in trunk control, wakefulness, tongue movement/chewing, older age, and a non-stroke diagnosis were also associated with tube feeding. BMI did not attenuate associations in sensitivity analyses. FOIS ratings had greatest density in FOIS level 1 and level 7, with 25% and 40% of registrations, respectively. Level 4 was rated in only 1% of 6,052 registrations. CONCLUSIONS: The FOIS was robustly associated with indicators of dysphagia. However, associations with postural control, wakefulness, age and diagnosis highlights that tube feeding may be attributed to other issues than dysphagia. It should be further investigated whether FOIS level 4 is meaningful in neurorehabilitation.

Neuromuscular electrical stimulation in early rehabilitation of Guillain-Barré syndrome: A pilot study.

INTRODUCTION: In Guillain-Barré syndrome (GBS), patients often develop muscle atrophy from denervation and immobilization. We, therefore, conducted a pilot study of neuromuscular electrical stimulation (NMES) to evaluate feasibility, safety, and effect on muscle wasting in the early phase of GBS. METHODS: Seventeen patients were randomized to receive 20 min of muscle fiber stimulation followed by 40 min of NMES of the right or left quadriceps muscle with the untreated side as control. Cross-sectional area (CSA) of the muscle measured by ultrasound and isometric knee extensor strength were the primary and secondary outcome measures. RESULTS: No treatment related adverse effects were recorded. Change in CSA was -0.25 cm2 (confidence interval [CI], -0.93-0.42) on the stimulated side versus -0.60 cm2 (CI, -1.32-0.11) on the nonstimulated side (P = 0.08). No effect was observed on muscle strength. CONCLUSIONS: NMES seems safe and feasible in the early phase of GBS. Further studies are needed to explore effect on muscle function. Muscle Nerve 59:481-484, 2019.

Lower Bowel Dysfunction Following Acquired Brain Injury: A Challenge During Rehabilitation.

The aim of this prospective, descriptive cohort study is to describe the prevalence of lower bowel dysfunction, possible relationship to diagnosis and severity, use of laxatives, and defecation patterns in patients with acquired brain injury during inpatient rehabilitation. Enrollment consisted of all patients admitted to an inpatient rehabilitation hospital (n = 98) within a 3-month period and assessments of fecal incontinence and fecal constipation at admission were performed. Documentation of used laxatives, number of defecations, and the macroscopic form during 4 weeks was conducted. Analysis of variance and Kruskal-Wallis analyses were conducted using the statistical software package STATA v 12/IC. At admission 75% of the patients suffered from lower bowel dysfunction, which was related to the severity of injury and age but not major diagnosis or gender. Of these, 68% suffered from fecal incontinence and 32% from fecal constipation. Ninety percent of the patients received laxatives during the initial 28 days. After 28 days, 20% continued to receive laxative treatment. There was no difference between weekly defecations in patients who had functional constipation and patients who had no bowel dysfunction. There was a strong relationship between bowel dysfunction status and prescribed laxative treatment. These findings indicate that lower gastrointestinal dysfunction is a long-lasting, profound complication following an acquired brain injury.

Can the health related quality of life measure QOLIBRI- overall scale (OS) be of use after stroke? A validation study.

BACKGROUND: Brief measures of health-related quality of life (HRQOL) that assess both patient-reported functioning and well-being after stroke are scarce. The objective of this study was to examine reliability and validity of one of these measures, the patient-reported Quality of Life after Brain Injury-Overall Scale (QOLIBRI-OS), in patients after stroke. METHODS: Stroke survivors were examined prospectively using survey methods. Core survey data (n = 125) and retest data (n = 36) were obtained at 3 and 12 months, respectively. Item properties (distribution, floor and ceiling effects), psychometric properties (reliability and model fit), and validity (correlations with established measures of anxiety, depression and HRQOL) of the QOLIBRI-OS were examined. RESULTS: Missing responses on the questionnaire were low (0.5%). All items were positively skewed. No floor effects were present, whereas five out of six items showed ceiling effects. The summary QOLIBRI-OS score exhibited no floor or ceiling effects, and had excellent internal consistency (Cronbach's α =0.93). All item-total correlations were high (0.73-0.88). The test-retest reliability of single items varied from 0.74 to 0.91 and was 0.93 for the overall score. The confirmatory factor analysis yielded an excellent fit for a five-item version and provided tentative support for the original six-item version. The convergent validity correlations were in the hypothesized directions, thus supporting the construct validity. CONCLUSIONS: The brief QOLIBRI-OS is a valid and reliable brief health-related outcome measure that is appropriate for screening HRQOL in patients after stroke.

Diffusion MRI findings in patients with extensive and minimal post-concussion symptoms after mTBI and healthy controls: a cross sectional study.

PRIMARY OBJECTIVES: We hypothesized that the microstructure of the corpus callosum, thalamus and hippocampus, as measured with diffusion and Mean of the Kurtosis Tensor (MKT) MRI, differs between healthy subjects and patients with extensive and minimal post-concussion symptoms (PCS) and that MKT measures correlate with PCS severity and self-reported cognitive symptoms. RESEARCH DESIGN: A cross-sectional study comparing patients with extensive PCS and patients with minimal PCS 2-5 months after mild traumatic brain injury (mTBI) with each other and with an external healthy control group. METHODS AND PROCEDURES: Diffusion MRI was obtained in 25 patients with extensive PCS and in 25 patients with minimal PCS as measured by the Rivermead Post-concussion Symptoms Questionnaire. The patients were matched on age, sex and time since accident. Data from an external healthy control group (n = 27) was included. MAIN OUTCOME AND RESULTS: There was no difference in MKT between the two groups with mTBI and no correlation between MKT and PCS. There was no difference between the three groups in other diffusion measures. CONCLUSIONS: Our results did not point to microstructural changes in the corpus callosum, thalamus and hippocampus in relation to PCS after mTBI.

Transcranial Direct Current Stimulation Potentiates Improvements in Functional Ability in Patients With Chronic Stroke Receiving Constraint-Induced Movement Therapy.

BACKGROUND AND PURPOSE: Transcranial direct current stimulation may enhance effect of rehabilitation in patients with chronic stroke. The objective was to evaluate the efficacy of anodal transcranial direct current stimulation combined with constraint-induced movement therapy of the paretic upper limb. METHODS: A total of 44 patients with stroke were randomly allocated to receive 2 weeks of constraint-induced movement therapy with either anodal or sham transcranial direct current stimulation. The primary outcome measure, Wolf Motor Function Test, was assessed at baseline and after the intervention by blinded investigators. RESULTS: Both groups improved significantly on all Wolf Motor Function Test scores. Group comparison showed improvement on Wolf Motor Function Test in the anodal group compared with the sham group. CONCLUSIONS: Anodal transcranial direct current stimulation combined with constraint-induced movement therapy resulted in improvement of functional ability of the paretic upper limb compared with constraint-induced movement therapy alone. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01983319.

Day-to-day features of soleus stretch reflexes in sub-acute stroke patients.

The aim of the study was to assess the reliability and variability of stretch reflex magnitude (SRmag) in sub-acute stroke patients. For testing, rapid dorsiflexion stretches were induced 24 h apart in 22 patients and 34 controls. SRmag between sessions in patients and controls was not different and the SRmag on the more-affected side was significantly larger than the less-affected, dominant, and non-dominant sides. The SRmag was consistent between sessions. Therefore, patients were not as variable between sessions as we had hypothesized.

Functional Independence: A Comparison of the Changes During Neurorehabilitation Between Patients With Nontraumatic Subarachnoid Hemorrhage and Patients With Intracerebral Hemorrhage or Acute Ischemic Stroke.

OBJECTIVE: To compare the changes in functional independence measured by the FIM after specialized neurorehabilitation between patients with nontraumatic subarachnoid hemorrhage (SAH) and patients with intracerebral hemorrhage (ICH) or acute ischemic stroke (AIS). DESIGN: Historical cohort study comparing changes in functional independence between patients with nontraumatic SAH and those with ICH/AIS, using FIM scores from a local database and clinical information from the Danish National Patient Registry. SETTING: Postacute specialized inpatient neurorehabilitation. PARTICIPANTS: Participants (N=660) comprised patients with a first-time nontraumatic SAH (n=212) and age-matched patients with a first-time ICH/AIS (n=448). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Crude and adjusted comparisons of FIM (total and item by item) measured at baseline and at discharge. RESULTS: Patients with nontraumatic SAH were admitted with a lower functional level compared with patients with ICH/AIS (median total FIM score, 25 [interquartile range (IQR), 18-81] vs 78.5 [IQR, 47-107]), and discharged with a lower functional level (median total FIM score, 98 [IQR, 40-116] vs 110 [IQR, 82.5-119]), although they made more progress during neurorehabilitation (median change in total FIM score, 27 [IQR, 4-60] vs 17 [IQR, 7-35]). Statistically, patients with nontraumatic SAH had significantly better odds for obtaining functional independence than did patients with ICH/AIS in 6 of the 18 FIM items: eating (odds ratio [OR]=3.2; 95% confidence interval [CI], 1.7-5.8); dressing-upper body (OR=2.0; 95% CI, 1.1-3.5); transfer tub/shower (OR=2.0; 95% CI, 1.1-3.6); stair walking (OR=2.2; 95% CI, 1.3-3.7); comprehension (OR=2.3; 95% CI, 1.3-3.9); and expression (OR=3.6; 95% CI, 2.0-6.5). CONCLUSIONS: Patients with nontraumatic SAH made significantly more progress during neurorehabilitation, although they were discharged with a lower level of functional independence compared with patients with ICH/AIS. However, both patients with nontraumatic SAH and those with ICH/AIS improved their functional outcome significantly. Also, patients with nontraumatic SAH admitted with severe functional outcome were shown to be capable of recovering to a moderate level of functional independence.

Return to Work After Severe Traumatic Brain Injury: A Nationwide Follow-up Study.

OBJECTIVE: To determine return to work (RTW) after severe traumatic brain injury (TBI) and to compare long-term labor market attachment (LMA) with the general population. PARTICIPANTS: All persons aged 18 to 64 years who received highly specialized neurorehabilitation after severe TBI between 2004 and 2012 (n = 637) were matched to general population controls on age, sex, preinjury employment status, educational level, and residence (n = 2497). DESIGN: Nationwide follow-up study using weekly records on public assistance benefits. MAIN MEASURES: Both RTW and LMA were defined as having no public assistance benefits except education grants/leave. Stable LMA was defined as weeks with LMA of 75% or more. LMA among persons with severe TBI and controls was compared using multivariable conditional logistic regression. RESULTS: RTW mainly occurred within first 2 years after severe TBI, with 30% of the people attempting RTW and 16% achieving stable LMA within 2 years. The prevalence of people with LMA decreased to 11% from 2½ years to 5 years postinjury. Adjusted odds ratios were 0.01 for LMA up to 2 years postinjury and 0.05 for stable LMA for persons with severe TBI compared with the general population. CONCLUSION: Both RTW and long-term LMA after severe TBI were low in Denmark when compared with the general population and other countries.

Alternative measures reveal different but low estimates of labour market attachment after severe traumatic brain injury: A nationwide cohort study.

OBJECTIVE: To explore if the definition of labour market attachment (LMA) changes LMA proportions after severe traumatic brain injury (TBI). DESIGN: Cohort study with 5-year follow-up. PARTICIPANTS: Patients aged 18-64 years with severe TBI from 2004 to 2012 (n = 637) and matched controls (n = 2497). METHODS: LMA was defined in three ways. All definitions included patients working with no government benefits. Definition 2 included patients receiving unemployment benefits (LMA-unemployment benefits). Definition 3 included patients receiving supplemental benefits/services such as patients involved in work-activation schemes (LMA supplementary benefits). First week of return to work (RTW), stable LMA first year after RTW and weekly LMA prevalence were calculated. Patients and controls were compared using multivariable conditional logistic regression. RESULTS: LMA unemployment benefits had similar proportions to LMA with no benefits. These estimates were lower than LMA supplemental benefits where 52% attempted to RTW and 31% achieved stable LMA within 2 years. The maximal LMA prevalence (LMA supplementary benefits) decreased from 33 to 30% from years 2 to 5. Adjusted odds ratios were 0.05 and 0.06 for years 1 and 2, and 0.07 for stable LMA in patients compared to controls. CONCLUSION: LMA proportions differed depending on the definition. Regardless of definition, LMA proportions following severe TBI were low in Denmark.

Microstructural changes in the thalamus after mild traumatic brain injury: A longitudinal diffusion and mean kurtosis tensor MRI study.

PRIMARY OBJECTIVE: The primary aim of this study was to assess microstructural changes in the thalamus, hippocampus and corpus callosum with a fast mean kurtosis tensor (MKT) technique, in the acute and sub-acute phase after mTBI. It was hypothesized that MKT would differ between baseline and follow-up in patients. The secondary aim was to relate diffusion measures to symptoms of mTBI. RESEARCH DESIGN: A longitudinal case-control study. METHODS AND PROCEDURES: Twenty-seven patients with mTBI and 27 age- and gender-matched healthy controls were enrolled in the study. Patients were scanned within 2 weeks and 3 months after mTBI, while the controls were scanned once. MAIN OUTCOMES AND RESULTS: MKT decreased significantly (p = 0.02) from baseline to follow-up in the thalamus in patients. Compared to healthy subjects, thalamic MKT values were significantly larger in patients at baseline (p = 0.048). Secondary analysis revealed a significant decrease (p = 0.01) in fractional anisotropy in the splenium of corpus callosum from baseline to follow-up. CONCLUSIONS: The current study indicates microstructural changes in the thalamus and corpus callosum from within 14 days to 3 months after mTBI and suggests MKT as a potential biomarker after mTBI.