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.

"Stroke - 65 plus. Continued active life." A randomized controlled trial of a self-management neurorehabilitation intervention for elderly people after stroke.

PURPOSE: Post-stroke sequelae among elderly often lead to a more inactive life while carrying a risk of overburdening close relatives. The objective of the present study was to determine if a novel self-management neuro-rehabilitation intervention added to usual treatment for people with stroke over the age of 65 years improved their self-efficacy. METHODS: This randomised controlled trial included participants two weeks before discharge from subacute rehabilitation. All participants received usual treatment. The intervention entailed an add-on of six to eight self-management sessions lasting 45-60 min within a period of nine months after discharge. This novel neuro-rehabilitation intervention focused on promoting growth, development and self-efficacy by facilitating the participants' self-management strategies regarding their activities and social network. All participants were assessed at baseline, three months and nine months after discharge. The primary outcome was self-efficacy measured by the Stroke Self-Efficacy Questionnaire. RESULTS: Sixty-nine individuals with stroke aged > 65 years were randomised. Their mean(SD) age was 76(6) years; 32 (46%) were female. No significant difference was found between the groups at baseline. Improvement recorded in the intervention group did not significantly differ from that of the control group with regard to primary outcome or secondary outcomes. CONCLUSIONS: This novel self-management intervention had no significant effect measured by the primary outcome self-efficacy or quality of life. Furthermore, no impact was observed on participation and autonomy compared with usual treatment.Clinical trial registration-URL: ClinicalTrials.gov, NCT03183960. Registered on 12 June 2017.

The present study testing a novel self-management neuro-rehabilitation intervention for people with stroke aged more than 65 years failed to improve self-efficacy, quality of life, and impact on participation and autonomy.Post hoc analyzes showed a lower caregiver burden at three and nine months in the intervention group as compared to the control group.The approach of perceiving the stroke individual and the informal caregiver as one unit (dyad), involving both in decisions regarding everyday activities and roles in everyday life especially within their shared part of life, appears important and warrants further development.

Interdisciplinary intervention (GAIN) for adults with post-concussion symptoms: a study protocol for a stepped-wedge cluster randomised trial.

BACKGROUND: Persistent post-concussion symptoms (PCS) are associated with prolonged disability, reduced health-related quality of life and reduced workability. At present, no strong evidence for treatments for people with persistent PCS exists. Our research group developed a novel intervention, "Get going After concussIoN (GAIN)", that incorporates multiple evidence-based strategies including prescribed exercise, cognitive behavioural therapy, and gradual return to activity advice. In a previous randomised trial, GAIN provided in a hospital setting was effective in reducing symptoms in 15-30-year-olds with PCS 2-6 months post-injury. In the current study, we describe the protocol for a trial designed to test the effectiveness of GAIN in a larger municipality setting. Additionally, we test the intervention within a broader age group and evaluate a broader range of outcomes. The primary hypothesis is that participants allocated to enhanced usual care plus GAIN report a higher reduction in PCS 3 months post-intervention compared to participants allocated to enhanced usual care only. METHODS: The study is a stepped-wedge cluster-randomised trial with five clusters. The 8-week interdisciplinary GAIN program will be rolled out to clusters in 3-month intervals. Power calculation yield at least 180 participants to be enrolled. Primary outcome is mean change in PCS measured by the Rivermead Post-Concussion Symptoms Questionnaire from enrolment to 3 months after end of treatment. Secondary outcomes include participation in and satisfaction with everyday activities, labour market attachment and other behavioural measures. Self-reported outcomes are measured at baseline, by end of treatment and at 3, 6, and 18 months after end of treatment. Registry-based outcomes are measured up to 36 months after concussion. DISCUSSION: The trial will provide important information concerning the effectiveness of the GAIN intervention in a municipality setting. Furthermore, it will provide knowledge of possible barriers and facilitators that may be relevant for future implementation of GAIN in different settings. TRIAL REGISTRATION: The current GAIN trial is registered in ClinicalTrials.gov (study identifier: NCT04798885 ) on 20 October 2020.

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.

Characterization of persistent post-traumatic headache and management strategies in adolescents and young adults following mild traumatic brain injury.

Characteristics of persistent post-traumatic headache (PTH) in young individuals are poorly known leading to diagnostic problems and diverse management. We aimed to describe headache phenotypes and self-reported management strategies in young individuals with PTH following mild traumatic brain injury (mTBI). A comprehensive structured questionnaire was used to evaluate headache phenotypes/characteristics and management strategies to relieve headache in 107, 15-30-year-old individuals with PTH. Around 4 months post-injury, migraine-like headache in combination with tension-type like headache (40%) was the most commonly encountered headache phenotype followed by migraine-like headache (36%). Around 50% reported aura-like symptoms before/during the headache attack. Medication-overuse headache was diagnosed in 10%. Stress, sleep disturbances, and bright lights were the most common trigger factors. More than 80% reported that their headache was worsened by work-related activity and alleviated by rest/lying down. Simple analgesics were commonly used (88%) whereas prophylactic drugs were rarely used (5%). Bedrest and physiotherapy were also commonly used as management strategies by 56% and 34% of the participants, respectively. In conclusion, most young individuals with PTH after mTBI presented with combined migraine-like and tension-type-like headache followed by migraine-like headache, only. Preventive headache medication was rarely used, while simple analgesics and bedrest were commonly used for short-term headache relief.

Monitoring Physical Behavior in Rehabilitation Using a Machine Learning-Based Algorithm for Thigh-Mounted Accelerometers: Development and Validation Study.

BACKGROUND: Physical activity is emerging as an outcome measure. Accelerometers have become an important tool in monitoring physical behavior, and newer analytical approaches of recognition methods increase the degree of details. Many studies have achieved high performance in the classification of physical behaviors through the use of multiple wearable sensors; however, multiple wearables can be impractical and lower compliance. OBJECTIVE: The aim of this study was to develop and validate an algorithm for classifying several daily physical behaviors using a single thigh-mounted accelerometer and a supervised machine-learning scheme. METHODS: We collected training data by adding the behavior classes-running, cycling, stair climbing, wheelchair ambulation, and vehicle driving-to an existing algorithm with the classes of sitting, lying, standing, walking, and transitioning. After combining the training data, we used a random forest learning scheme for model development. We validated the algorithm through a simulated free-living procedure using chest-mounted cameras for establishing the ground truth. Furthermore, we adjusted our algorithm and compared the performance with an existing algorithm based on vector thresholds. RESULTS: We developed an algorithm to classify 11 physical behaviors relevant for rehabilitation. In the simulated free-living validation, the performance of the algorithm decreased to 57% as an average for the 11 classes (F-measure). After merging classes into sedentary behavior, standing, walking, running, and cycling, the result revealed high performance in comparison to both the ground truth and the existing algorithm. CONCLUSIONS: Using a single thigh-mounted accelerometer, we obtained high classification levels within specific behaviors. The behaviors classified with high levels of performance mostly occur in populations with higher levels of functioning. Further development should aim at describing behaviors within populations with lower levels of functioning.

Nonpharmacological Treatment of Persistent Postconcussion Symptoms in Adults: A Systematic Review and Meta-analysis and Guideline Recommendation.

Importance: Persistent (>4 weeks) postconcussion symptoms (PPCS) are challenging for both patients and clinicians. There is uncertainty about the effect of commonly applied nonpharmacological treatments for the management of PPCS. Objective: To systematically assess and summarize evidence for outcomes related to 7 nonpharmacological interventions for PPCS in adults (aged >18 years) and provide recommendations for clinical practice. Data Sources: Systematic literature searches were performed via Embase, MEDLINE, PsycINFO, CINAHL, PEDro, OTseeker, and Cochrane Reviews (via MEDLINE and Embase) from earliest possible publication year to March 3, 2020. The literature was searched for prior systematic reviews and primary studies. To be included, studies had to be intervention studies with a control group and focus on PPCS. Study Selection: A multidisciplinary guideline panel selected interventions based on frequency of use and need for decision support among clinicians, including early information and advice, graded physical exercise, vestibular rehabilitation, manual treatment of neck and back, oculomotor vision treatment, psychological treatment, and interdisciplinary coordinated rehabilitative treatment. To be included, studies had to be intervention studies within the areas of the predefined clinical questions, include a control group, and focus on symptoms after concussion or mild traumatic brain injury. Data Extraction and Synthesis: Extraction was performed independently by multiple observers. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used for data abstraction and data quality assessment. Included studies were assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) tool and the Cochrane Risk of Bias (randomized clinical trials) tool. Meta-analysis was performed for all interventions where possible. Random-effects models were used to calculate pooled estimates of effects. The level and certainty of evidence was rated and recommendations formulated according to the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework. Main Outcomes and Measures: All outcomes were planned before data collection began according to a specified protocol. The primary outcomes were the collective burden of PPCS and another outcome reflecting the focus of a particular intervention (eg, physical functioning after graded exercise intervention). Results: Eleven systematic reviews were identified but did not contribute any primary studies; 19 randomized clinical trials comprising 2007 participants (1064 women [53.0%]) were separately identified and included. Evidence for the 7 interventions ranged from no evidence meeting the inclusion criteria to very low and low levels of evidence. Recommendations were weak for early information and advice, graded physical exercise, vestibular rehabilitation, manual treatment of the neck and back, psychological treatment, and interdisciplinary coordinated rehabilitative treatment. No relevant evidence was identified for oculomotor vision treatment, so the panel provided a good clinical practice recommendation based on consensus. Conclusions and Relevance: Based on very low to low certainty of evidence or based on consensus, the guideline panel found weak scientific support for commonly applied nonpharmacological interventions to treat PPCS. Results align with recommendations in international guidelines. Intensified research into all types of intervention for PPCS is needed.

Incidence of Free of Charge Physiotherapy in a Danish National Cohort of Stroke, Parkinson's Disease, Multiple Sclerosis and Rheumatoid Arthritis Patients.

BACKGROUND: Denmark is a welfare state with a publically funded healthcare system that includes the right to free of charge physiotherapy (FCP) for patients with chronic or progressive disease who fulfill strict criteria. The aim of this study was to investigate the incidence of referral to FCP in patients with a hospital diagnosis of stroke, multiple sclerosis (MS), Parkinson's disease (PD) and rheumatoid arthritis (RA) between 2007 and 2016. METHODS: The study was register-based and included data from The Danish National Patient Registry and The National Health Service Registry. The study population included the four largest disease groups receiving FCP in Denmark. The incidence of receiving FCP was reported as the cumulated incidence proportion (CIP). RESULTS: The study showed that FCP was mainly initiated within the first 2 years after diagnosis. The 2-year CIP was 8% for stroke patients, 53% for PD patients, 49% for MS patients, and 16% for RA patients. The proportion of patients referred to FCP generally increased over the period of the study due to more patients being referred from medical specialists in primary care. CONCLUSION: This study found substantial differences in the incidence of referral to FCP in a Danish population of stroke, PD, MS and RA patients.

A study of the discriminative properties of the Six-Spot Step Test in people with Parkinson's disease at risk of falling.

BACKGROUND: Clinical tests that can discriminate between people at risk of falling and those not at risk are warranted. The discriminative properties of the Six-Spot Step Test was investigated in people with Parkinson's disease at risk of falling. METHODS: Eighty-one participants with a median age of 69 years (Q1-Q3:63-74) and a median Hoehn and Yahr score of 2.5 (Q1-Q3:2-3) completed the Six-Spot Step Test and the Timed "Up and Go" test. A mini-BESTest score of 19 or below was used as a cut-off for defining risk of falling, and a receiver operating characteristics curve was generated to determine clinical relevant cut-off scores. RESULTS: A cut-off score of 7.0 and 6.8 seconds identified people not at risk of falling, while 11.1 and 9.4 seconds identified people at risk of falling for the Six-Spot Step Test and the Timed "Up and Go" test, respectively. When maximizing the sensitivity and specificity a cut-off score of 9.2 (accuracy of 84%) and 8.1 seconds (accuracy of 70%) was found for the Six-Spot Step Test and the Timed "Up and Go" test, respectively. CONCLUSION: The Six-Spot Step Test discriminates accurately between people with Parkinson's disease at risk of falling and people not at risk.

Neuromuscular effects of dorsiflexor training with and without blood flow restriction.

Blood flow restriction training (BFRT) has been proposed for elderly and clinical populations with weakness. Before being used in these populations it is important to understand the neurological effects of, and subject perceptions to, BFRT. Seventeen healthy subjects were recruited and performed 2 experimental sessions, BFRT and training without blood flow restriction (TR-only), on separate days. Four sets of concentric/eccentric dorsiflexion contractions against theraband resistance were performed. Surface electromyography of the tibialis anterior was recorded during exercise and for the electrophysiological measures. At baseline, immediately-post, 10-min-post and 20-min-post exercise, motor evoked potentials (MEPs) from single pulse transcranial magnetic stimulation (TMS), paired-pulse TMS with interstimulus intervals of 2-ms (SICI) and 15-ms (ICF), and the M-max amplitude were recorded in the resting TA. Following training, subjects provided a numerical rating of the levels of pain, discomfort, fatigue, focus and difficulty during training. Muscle activation was higher in the last 20 contractions during BFRT compared to TR. There was no difference (time × condition interaction) between BFRT and TR for single-pulse MEP, SICI, ICF or M-max amplitude. There was a significant main effect of timepoint for single-pulse MEP and M-max amplitudes with both significantly reduced for 20-min-post exercise. No reductions were observed for SICI and ICF amplitudes. Taken together, BFRT and TR-only were only different during exercise and both regimes induced similar significant reductions in M-Max and MEP-amplitude post-training. Due to the lack of changes in SICI and ICF, it is unlikely that changes occurred in cortical sites related to these pathways. The increased surface electromyography activity in the last 20 contractions, indicate that the training regimes are different and that BFRT possibly induces more fatigue than TR. As such, BFRT could be used as an adjunct to conventional training. However, as subjects perceived BFRT as more painful, difficult and uncomfortable than TR-only, people should be selected carefully to undertake BFRT.

Novel interdisciplinary intervention, GAIN, vs. enhanced usual care to reduce high levels of post-concussion symptoms in adolescents and young adults 2-6 months post-injury: A randomised trial.

BACKGROUND: Evidence for effective interventions to prevent long-term sequelae after concussion is sparse. This study aimed to test the efficacy of Get going After concussIoN (GAIN), an interdisciplinary, individually-tailored intervention of 8 weeks duration based on gradual return to activities and principles from cognitive behavioural therapy. METHODS: We conducted an open-label, parallel-group randomised trial in a hospital setting in Central Denmark Region. Participants were 15-30-year-old patients with high levels of post-concussion symptoms (PCS) 2-6 months post-concussion (i.e., a score ≥20 on the Rivermead Post-concussion Symptoms Questionnaire (RPQ)). They were randomly assigned (1:1) to either enhanced usual care (EUC) or GAIN+EUC. Masking of participants and therapists was not possible. The primary outcome was change in RPQ-score from baseline to 3-month FU. All analyses were done on an intention-to-treat basis using linear mixed-effects models. This trial is registered with ClinicalTrials.gov, number NCT02337101. FINDINGS: Between March 1, 2015, and September 1, 2017, we included 112 patients. Patients allocated to GAIN+EUC (n=57) reported a significantly larger reduction of PCS than patients allocated to EUC (n=55) with a mean adjusted difference in improvement of 7·6 points (95% confidence interval (CI) 2·0-13·1, p=0·008), Cohen's d=0·5 (95% CI 0·1-0·9). Number needed to treat for prevention of one additional patient with RPQ ≥20 at 3-month FU was 3·6 (95% CI 2·2-11·3). No adverse events were observed. INTERPRETATION: Compared with EUC, GAIN+EUC was associated with a larger reduction of post-concussion symptoms at 3-month FU. FUNDING: Central Denmark Region and the foundation "Public Health in Central Denmark Region - a collaboration between municipalities and the region".

"Stroke - 65 Plus. Continued Active Life": a study protocol for a randomized controlled cross-sectoral trial of the effect of a novel self-management intervention to support elderly people after stroke.

BACKGROUND: Elderly people represent the majority of stroke cases worldwide. Post-stroke sequelae frequently lead to a more isolated life. Restricted social relations render older individuals with stroke a vulnerable group, especially in terms of social reintegration. Reintegration into the community after a stroke largely depends on support from the family. However, close relatives are at risk of becoming overburdened. The aim of this study is to investigate the effect of a novel self-management intervention to support elderly people after stroke. METHODS/DESIGN: Randomized controlled trial. Two weeks before discharge from a rehabilitation hospital/center, individuals with stroke aged > 65 years will be randomized either to a group receiving conventional neurorehabilitation (control) or to an additional novel self-management intervention. In the intervention group, patients with stroke will be offered eight self-management sessions of 45-60 min duration by a physiotherapist or an occupational therapist during a period of nine months after discharge. Inclusion will continue until at least 35 individuals in each group have been recruited. Study outcome measurements: Stroke Self-efficacy Questionnaire, a short version of Stroke Specific Quality of Life Scale, Impact on Participation and Autonomy and Caregiver Burden Scale. Furthermore, physical activity will be assessed using accelerometers. All outcomes except "impact on participation" and "autonomy" will be assessed at baseline, three months, and nine months after discharge. Impact on participation and autonomy will be assessed at three and nine months after discharge. Patient, informal caregiver, and therapist satisfaction will be examined by way of questionnaires and interviews. DISCUSSION: Self-management interventions are promising strategies for rehabilitation, potentially increasing self-efficacy, quality of life, as well as participation and autonomy. The introduction of a novel self-management intervention in combination with traditional physical and occupational therapy may enhance recovery after stroke and quality of life and lessen the burden on relatives. This trial "Stroke - 65 Plus. Continued Active Life," will provide further evidence of self-management strategies to clinicians, patients, and health economists. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03183960 . Registered on 12 June 2017.

Design of an early intervention for persistent post-concussion symptoms in adolescents and young adults: A feasibility study.

BACKGROUND: About 5-15 % of patients with concussion experience persistent post-concussion symptoms (PCS) longer than 3 months post-injury. OBJECTIVE: To explore the feasibility of a new intervention for young patients with persistent PCS and long-term changes after intervention. METHODS: Thirty-two consecutive patients (15-30 years) with persistent PCS 2-4 months post-injury were recruited from a cohort study or referred to a non-randomized feasibility study of an individually tailored, 8-week, multidisciplinary intervention. Assessment was performed at baseline, end of intervention (EOI), and at 3- and 12-month follow-up (FU). Main measures were The Experience of Service Questionnaire (ESQ), Rivermead Post-Concussion Symptoms Questionnaire (RPQ) and The Quality of Life after Brain Injury - Overall Scale (QOLIBRI-OS). RESULTS: Twenty-three (72%) patients completed the intervention. The ESQ demonstrated high patient satisfaction. There was a decrease of PCS and an increase in quality of life from baseline to EOI: RPQ score -8.9 points, 95% CI 4.5 to 13.3, p < 0.001; QOLIBRI-OS score +10.5 points, 95% CI 2.5 to 18.5, p = 0.010. Improvement was maintained at 3- and 12-month FU. CONCLUSION: The new early intervention is feasible and may prevent chronification of PCS. An RCT is currently performed to evaluate the effect of the intervention.

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.

Corticospinal excitability changes following blood flow restriction training of the tibialis anterior: a preliminary study.

AIM: To examine the neural excitability of projections to the tibialis anterior (TA) following blood flow restriction training (BFRT). This is the first study to examine the TA following BFRT. METHODS: Ten subjects performed each experiment. Experiment one consisted of BFRT at 130 mmHg (BFRT-low). Experiment two consisted of BFRT at 200 mmHg (BFRT-high), training (TR-only) and blood flow restriction at 200 mmHg (BFR-only) performed on separate days. Blood flow restriction was applied to the thigh and training consisted of rapid dorsiflexion contractions against gravity every 10 s for 15-min. The motor evoked potential (MEP) peak-to-peak amplitudes were recorded pre-intervention and 1-, 10-, 20- and 30-min post-intervention and expressed relative to the maximal peak-to-peak M-wave at each time-point. RESULTS: Experiment one revealed no difference in MEP amplitudes for BFRT-low over time (P = 0.09). Experiment two revealed a significant effect of time (P < 0.001), with 1-min post-intervention MEP amplitudes significantly facilitated compared to pre-intervention, but no effect of intervention (P = 0.79) or intervention*time interaction (P = 0.25). Post-hoc power calculations were performed for the intervention*time interaction. DISCUSSION AND CONCLUSIONS: Corticospinal excitability of projections to the TA did not change following BFRT-low and corticospinal excitability changes between BFRT-high, BFR-only and TR-only interventions were not different over time. In experiment two, there was a significant main effect of time 1-min post-intervention which was mainly due to the BFRT-high intervention. Post-hoc power calculations revealed that 15 subjects were required for a significant interaction effect 80% of the time however, as the changes in corticospinal excitability were not prolonged, a new dataset of ≥ 15 subjects was not acquired.

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.

The role of the microcirculation in delayed cerebral ischemia and chronic degenerative changes after subarachnoid hemorrhage.

The mortality after aneurysmal subarachnoid hemorrhage (SAH) is 50%, and most survivors suffer severe functional and cognitive deficits. Half of SAH patients deteriorate 5 to 14 days after the initial bleeding, so-called delayed cerebral ischemia (DCI). Although often attributed to vasospasms, DCI may develop in the absence of angiographic vasospasms, and therapeutic reversal of angiographic vasospasms fails to improve patient outcome. The etiology of chronic neurodegenerative changes after SAH remains poorly understood. Brain oxygenation depends on both cerebral blood flow (CBF) and its microscopic distribution, the so-called capillary transit time heterogeneity (CTH). In theory, increased CTH can therefore lead to tissue hypoxia in the absence of severe CBF reductions, whereas reductions in CBF, paradoxically, improve brain oxygenation if CTH is critically elevated. We review potential sources of elevated CTH after SAH. Pericyte constrictions in relation to the initial ischemic episode and subsequent oxidative stress, nitric oxide depletion during the pericapillary clearance of oxyhemoglobin, vasogenic edema, leukocytosis, and astrocytic endfeet swelling are identified as potential sources of elevated CTH, and hence of metabolic derangement, after SAH. Irreversible changes in capillary morphology and function are predicted to contribute to long-term relative tissue hypoxia, inflammation, and neurodegeneration. We discuss diagnostic and therapeutic implications of these predictions.