Reliability and Sensitivity of a Virtual Assessment Developed for Workplace Concussions: Protocol for a Method-Comparison Study.

BACKGROUND: Workplace mild traumatic brain injuries are frequently associated with persistent symptoms, leading to a reduction in productivity at work or even disability. People who sustain workplace injuries frequently need rehabilitation and support, and the challenges of delivering these services was heightened during the COVID-19 pandemic as injured workers had to be cared for remotely. Currently, clinicians are conducting both in-person and virtual (remote) concussion assessments; however, the measures that are being used to complete these assessments have undocumented psychometric properties. OBJECTIVE: This study will document the psychometric properties of the clinical measures that are being used remotely and their ability to produce similar results to in-person assessments. Specifically, through this method-comparison study, we aim to (1) evaluate the sensitivity of the measures included in a virtual assessment toolkit when compared to an in-person assessment and (2) determine the interrater and intrarater reliabilities of the measures included in a virtual assessment toolkit. METHODS: Patient participants (people living with acquired brain injuries) will attend two assessments (in person and virtual) at the Ottawa Hospital. The two assessments will be identical, consisting of the measures included in our previously developed virtual concussion assessment toolkit, which includes finger-to-nose testing, the Vestibular/Ocular Motor Screening tool, balance testing, cervical spine range of motion, saccades testing, and evaluation of effort. All virtual assessments will occur using the Microsoft Teams platform and will be audio/video-recorded. The clinician assessor and patient participant will complete a feedback form following completion of the assessments. A different clinician will also document the findings on observed videos of the virtual assessment shortly after completion of both in-person and virtual assessments and approximately 1 month later. Interrater reliability will be assessed by comparing the second clinician's observation with the first clinician's initial virtual assessment. Intrarater reliability will be evaluated by comparing the second clinician's observation with their own assessment approximately 1 month later. Sensitivity will be documented by comparing the findings (identification of abnormality) of the in-person assessment completed by the initial clinician assessor with those of the second clinician assessor on the observation of the recording of the virtual assessment. RESULTS: As of May 2024, we have recruited 7 clinician assessors and completed study assessments with 39 patient participants. The study recruitment is expected to be completed by September 2024. CONCLUSIONS: Currently, it is unknown if completing concussion assessments virtually produces similar results to the in-person assessment. This work will serve as a first step to determining the similarity of the virtual assessment to the matching in-person assessment and will provide information on the reliability of the virtual assessment. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/57663.

Inflammatory cytokines associated with mild traumatic brain injury and clinical outcomes: a systematic review and meta-analysis.

Mild traumatic brain injuries (mTBIs) trigger a neuroinflammatory response, which leads to perturbations in the levels of inflammatory cytokines, resulting in a distinctive profile. A systematic review and meta-analysis were conducted to synthesize data related to levels of inflammatory cytokines in patients with mTBI. The electronic databases EMBASE, MEDLINE, and PUBMED were searched from January 2014 to December 12, 2021. A total of 5,138 articles were screened using a systematic approach based on the PRISMA and R-AMSTAR guidelines. Of these articles, 174 were selected for full-text review and 26 were included in the final analysis. The results of this study demonstrate that within 24 hours, patients with mTBI have significantly higher levels of Interleukin-6 (IL-6), Interleukin-1 Receptor Antagonist (IL-1RA), and Interferon-γ (IFN-γ) in blood, compared to healthy controls in majority of the included studies. Similarly one week following the injury, patients with mTBI have higher circulatory levels of Monocyte Chemoattractant Protein-1/C-C Motif Chemokine Ligand 2 (MCP-1/CCL2), compared to healthy controls in majority of the included studies. The results of the meta-analysis also confirmed these findings by demonstrating significantly elevated blood levels of IL-6, MCP-1/CCL2, and Interleukin-1 beta (IL-1ß) in the mTBI population compared to healthy controls (p < 0.0001), particularly in the acute stages (<7 days). Furthermore, it was found that IL-6, Tumor Necrosis Factor-alpha (TNF-α), IL-1RA, IL-10, and MCP-1/CCL2 were associated with poor clinical outcomes following the mTBI. Finally, this research highlights the lack of consensus in the methodology of mTBI studies that measure inflammatory cytokines in the blood, and also provides direction for future mTBI research.

Identification of Clinical Measures to Use in a Virtual Concussion Assessment: Protocol for a Mixed Methods Study.

BACKGROUND: Workplace concussions can have a significant impact on workers. The impact of concussion symptoms, combined with challenges associated with clinical environments that are loud, bright, and busy, create barriers to conducting effective in-person assessments. Although the opportunity for remote care in rural communities has long been recognized, the COVID-19 pandemic has catalyzed the transition to virtual assessments and care into the mainstream. With this rapid shift, many clinicians have been completing remote assessments. However, the approaches and measures used in these assessments have not yet been standardized. Furthermore, the psychometric properties of the assessments when completed remotely using videoconference have not yet been documented. OBJECTIVE: Through this mixed methods study, we aim to (1) identify the concussion assessment measures clinicians are currently using in person and are most relevant to the following 5 physical domains: neurological examination (ie, cranial nerve, coordination, motor, and sensory skills), cervical spine, vestibular, oculomotor, and effort assessment; (2) document the psychometric properties of the measures identified; (3) identify measures that appear feasible in a virtual context; and (4) identify practical and technical barriers or challenges, facilitators, and benefits to conducting or engaging in virtual concussion assessments. METHODS: This study will follow a sequential mixed methods design using a survey and Delphi approach, working groups with expert clinicians, and focus groups with experienced clinicians and people living with concussions. Our target sample sizes are 50 clinicians for the Delphi surveys, 4 clinician-participants for the working group, and 5-7 participants for each focus group (roughly 6-10 total groups being planned with at least two groups consisting of people living with concussions). The results from this study will inform the decision regarding the measures that should be included in a virtual assessment tool kit to be tested in a future planned prospective evaluation study. RESULTS: The study is expected to be completed by January 2023. CONCLUSIONS: This mixed methods study will document the clinical measures that are currently used in person and will identify those that are most relevant to assessing the physical domains impacted by concussions. Potential feasibility of using these measures in a virtual context will be explored. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/40446.

Decreased Expression of Cerebral Dopamine Neurotrophic Factor in Platelets of Probable Alzheimer Patients.

BACKGROUND: Alzheimer disease (AD) patients experience progressive neurological and cognitive decline attributed to neurodegeneration. Cerebral dopamine neurotrophic factor (CDNF) has been identified to protect and rescue neurons in various preclinical neurodegeneration models. The expression of this protein occurs in both the central nervous system and peripheral blood. Blood platelets exhibit several biochemical impairments similar to the brain tissues of patients with neurological disorders. This study examines CDNF mRNA expression in human blood platelets in healthy subjects and Alzheimer-probable patients. METHODS: Platelets were extracted from whole blood from patients. mRNA was extracted to synthesize cDNA and quantify CDNF gene expression from 21 Alzheimer-probable patients and 73 healthy age-matched control subjects using real-time qPCR. Grouping analysis of the data with regard to sex was conducted. RESULTS: CDNF mRNA expression was significantly decreased in Alzheimer-probable patients relative to the control subjects (P<0.05). Further analysis demonstrated reduced CDNF expression in male Alzheimer-probable patients compared with their age and sex-matched controls (P<0.05). However, no change in female subjects was observed. Interestingly, there is a lower level of CDNF expression in the female control group relative to the control male group (P<0.05). CONCLUSION: Alzheimer-probable male patients demonstrated significant reductions in CDNF expression, suggesting that CDNF plays a significant role in the pathogenesis of AD. In addition, it may assist in diagnosing male Alzheimer patients.

Correlation between Mild Traumatic Brain Injury-Induced Inflammatory Cytokines and Emotional Symptom Traits: A Systematic Review.

Both mild traumatic brain injuries (mTBI) and systemic injuries trigger a transient neuroinflammatory response that result in similar clinical outcome. The ensuing physical, cognitive, and emotional symptoms fail to subside in approximately 15-20% of the concussed population. Emotional impairments, particularly depression, anxiety, and post-traumatic stress disorder (PTSD), are commonly associated with poor recovery following mTBI. These emotional impairments also have a significant neuroinflammatory component. We hypothesized that the inflammatory cytokines seen in mTBI patients with emotional symptoms would coincide with those commonly seen in patients with emotional symptoms without mTBI. A systematic review was conducted to identify the most common neuroinflammatory cytokines in the mTBI population with psychological symptoms (depression, anxiety, PTSD). The electronic databases EMBASE, MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), PUBMED, and PSYCINFO were searched from data inception to 31 August 2021. A systematic screening approach was employed from screening to data analysis. A total of 994 articles were screened, 108 were selected for full article review, and 8 were selected for data analysis. The included studies consisted of 875 patients of which 81.3% were male. The mean sample size of patients with at least one mTBI was 73.8 ± 70.3 (range, 9-213), with a mean age of 33.9 ± 4.8 years. The most common cytokines associated with poor psychological outcomes involving PTSD and/or depression in the chronic mTBI population were IL-6, TNFα, IL-10, and CRP.

Altered motor system function in post-concussion syndrome as assessed via transcranial magnetic stimulation.

OBJECTIVE: It is unclear why specific individuals incur chronic symptoms following a concussion. This exploratory research aims to identify and characterize any neurophysiological differences that may exist in motor cortex function in post-concussion syndrome (PCS). METHODS: Fifteen adults with PCS and 13 healthy, non-injured adults were tested. All participants completed symptom questionnaires, and transcranial magnetic stimulation (TMS) was used to measure intracortical and transcallosal excitability and inhibition in the dominant motor cortex. RESULTS: Cortical silent period (p = 0.02, g = 0.96) and ipsilateral silent period (p = 0.04, g = 0.78) were shorter in the PCS group compared to the control group which may reflect reduced GABA-mediated inhibition in PCS. Furthermore, increased corticomotor excitability was observed in the left hemisphere but not the right hemisphere. CONCLUSIONS: These data suggest that persistent neurophysiological differences are present in those with PCS. The exact contributing factors to such changes remain to be investigated by future studies. SIGNIFICANCE: This study provides novel evidence of lasting neurophysiological changes in PCS.

Performances on individual neurocognitive tests by people experiencing a current major depression episode: A systematic review and meta-analysis.

BACKGROUND AND PURPOSES: Previous meta-analyses on neurocognitive test performances in depression have provided effect sizes for cognitive domains. Most domain effect sizes have medium to high variance heterogeneity. Restriction to each test performance could reduce variance and clarify differing test effect sizes. This systematic review and meta-analysis were done to 1. provide effect sizes for cognitive performances (test, subtest, or multiple measures within tests), and 2. investigate age as an effect modifier. METHODS: Inclusion criteria were: 1. active major depression episode (MD), 2. a control group, 3 reported means and standard deviations, 4. non-computerized tests previously studied at least 3 times. Meta-analyses were performed using Cochrane Review Manager. Age under versus over 45 was investigated as an effect moderator. RESULTS: Twenty-seven studies met criteria. MD patients performed significantly poorer on 16 of 16 neurocognitive measures (random effects d = -0.47 to -0.92 across tests). Variance was heterogeneous for 11 of 16 measures. Differences between cognitive measures were largely absent based on overlapping 95% confidence intervals. Effect sizes did not differ under versus over 45 years. LIMITATIONS: Bias risk assessment showed limited control for subject selection, comparability of depressed and control groups, pre-morbid intelligence, drug treatment, and effort in testing. CONCLUSIONS: The depression - cognition effect was in the moderate to large range regardless of test type. Variance heterogeneity was substantial despite exclusion of inactive depression and the absence of test pooling. The size of the depression - cognition effect was not a function of age.

Decreased Expression of Cerebral Dopamine Neurotrophic Factor in Platelets of Stroke Patients.

BACKGROUND: Cerebral dopamine neurotrophic factor plays a critical role in repairing and maintaining healthy neurons in pathological conditions such as stroke. However, the association between cerebral dopamine neurotrophic factor expression and stroke has only recently been investigated in preclinical models and is rarely described in human studies. OBJECTIVES: The aims of this were to examine neurological alterations mirrored in human blood platelet cerebral dopamine neurotrophic factor gene expression. Cerebral dopamine neurotrophic factor is expressed in both the central nervous system and peripheral blood. Blood platelets are often used to model neuronal behavior because they exhibit biochemical impairments similar to brain tissues of patients with neurological disorders. METHODS: RNA was isolated from platelets and cDNA was synthesized to quantify cerebral dopamine neurotrophic factor gene expression of 36 stroke patients compared to 72 healthy aged-matched controls through real-time PCR. Further grouping analyses of data with regard to age, sex, and medication history were performed. RESULTS: Cerebral dopamine neurotrophic factor gene expression was significantly reduced in stroke patients relative to control subjects (P = .013). Subsequent analysis revealed a significant difference in expression between males and females within the control group (P = .026). Decreased cerebral dopamine neurotrophic factor expression was only observed in male stroke patients compared to their sex-matched controls (P = .008). Grouping stroke patients based on their medication history did not significantly alter cerebral dopamine neurotrophic factor gene expression. CONCLUSIONS: Further studies investigating cerebral dopamine neurotrophic factor expression could be directed towards the interplay of the central nervous system, hematopoietic derivatives, and utilizing cerebral dopamine neurotrophic factor as a therapeutic tool.

Modulation of the TGF-ß1-induced epithelial to mesenchymal transition (EMT) mediated by P1 and P2 purine receptors in MDCK cells.

Epithelial to mesenchymal transition (EMT) occurs during embryogenesis or under pathological conditions such as hypoxia, injury, chronic inflammation, or tissue fibrosis. In renal tubular epithelial cells (MDCK), TGF-ß1 induces EMT by reducing or increasing epithelial or mesenchymal marker expression, respectively. In this study, we confirmed that the cAMP analogues, 8-CPT-cAMP or N6-Ph-cAMP, inhibited the TGF-ß1-driven overexpression of the mesenchymal markers ZEB-1, Slug, Fibronectin, and α-SMA. Furthermore, we showed that A1, A2A, P2Y1, P2Y11, and P2X7 purine receptor agonists modulated the TGF-ß1-induced EMT through the involvement of PKA and/or MAPK/ERK signaling. The stimulation of A2A receptor reduced the overexpression of the EMT-related markers, mainly through the cAMP-dependent PKA pathway, as confirmed by cell pre-treatment with Myr-PKI. Both A1 and P2Y1 receptor stimulation exacerbated the TGF-ß1-driven effects, which were reduced by cell pre-treatment with the MAPK inhibitor PD98059, according to the increased ERK1/2 phosphorylation upon receptor activation. The effects induced by P2Y11 receptor activation were oppositely modulated by PKA or MAPK inhibition, in line with the dual nature of the Gs- and Gq-coupled receptor. Differently, P2X7 receptor induced, per se, similar and not additive effects compared to TGF-ß1, after prolonged cell exposure to BzATP. These results suggest a putative role of purine receptors as target for anti-fibrotic agents.

Evidence for purine nucleoside phosphorylase (PNP) release from rat C6 glioma cells.

Intracellular purine turnover is mainly oriented to preserving the level of triphosphate nucleotides, fundamental molecules in vital cell functions that, when released outside cells, act as receptor signals. Conversely, high levels of purine bases and uric acid are found in the extracellular milieu, even in resting conditions. These compounds could derive from nucleosides/bases that, having escaped to cell reuptake, are metabolized by extracellular enzymes similar to the cytosolic ones. Focusing on purine nucleoside phosphorylase (PNP) that catalyzes the reversible phosphorolysis of purine (deoxy)-nucleosides/bases, we found that it is constitutively released from cultured rat C6 glioma cells into the medium, and has a molecular weight and enzyme activity similar to the cytosolic enzyme. Cell exposure to 10 µM ATP or guanosine triphosphate (GTP) increased the extracellular amount of all corresponding purines without modifying the levels/activity of released PNP, whereas selective activation of ATP P2Y1 or adenosine A2A metabotropic receptors increased PNP release and purine base formation. The reduction to 1% in oxygen supply (2 h) to cells decreased the levels of released PNP, leading to an increased presence of extracellular nucleosides and to a reduced formation of xanthine and uric acid. Conversely, 2 h cell re-oxygenation enhanced the extracellular amounts of both PNP and purine bases. Thus, hypoxia and re-oxygenation modulated in opposite manner the PNP release/activity and, thereby, the extracellular formation of purine metabolism end-products. In conclusion, extracellular PNP and likely other enzymes deputed to purine base metabolism are released from cells, contributing to the purinergic system homeostasis and exhibiting an important pathophysiological role.

Exercise Training in Progressive Multiple Sclerosis: A Comparison of Recumbent Stepping and Body Weight-Supported Treadmill Training.

Background: There is evidence of the benefits of exercise training in multiple sclerosis (MS); however, few studies have been conducted in individuals with progressive MS and severe mobility impairment. A potential exercise rehabilitation approach is total-body recumbent stepper training (TBRST). We evaluated the safety and participant-reported experience of TBRST in people with progressive MS and compared the efficacy of TBRST with that of body weight-supported treadmill training (BWSTT) on outcomes of function, fatigue, and health-related quality of life (HRQOL). Methods: Twelve participants with progressive MS (Expanded Disability Status Scale scores, 6.0-8.0) were randomized to receive TBRST or BWSTT. Participants completed three weekly sessions (30 minutes) of exercise training for 12 weeks. Primary outcomes included safety assessed as adverse events and patient-reported exercise experience assessed as postexercise response and evaluation of exercise equipment. Secondary outcomes included the Multiple Sclerosis Functional Composite, the Modified Fatigue Impact Scale, and the Multiple Sclerosis Quality of Life-54 questionnaire scores. Assessments were conducted at baseline and after 12 weeks. Results: Safety was confirmed in both exercise groups. Participants reported enjoying both exercise modalities; however, TBRST was reviewed more favorably. Both interventions reduced fatigue and improved HRQOL (P ≤ .05); there were no changes in function. Conclusions: Both TBRST and BWSTT seem to be safe, well tolerated, and enjoyable for participants with progressive MS with severe disability. Both interventions may also be efficacious for reducing fatigue and improving HRQOL. TBRST should be further explored as an exercise rehabilitation tool for patients with progressive MS.

Magnitude and variability of effect sizes for the associations between chronic pain and cognitive test performances: a meta-analysis.

OBJECTIVES AND METHODS: A systematic review and meta-analysis were performed to estimate the size and variability of the association between chronic pain (CP) and poorer cognitive test performances as a function of individual tests, pain sub-types, and study sources on 22 studies having (1) a control group, (2) reported means and standard deviations (SDs) and (3) tests studied at least 3 times. RESULTS: CP patients performed significantly poorer with small to moderate effects (d = -.31 to -.57) on Digit Span Backward; STROOP Word; Color and Color-Word; Digit Symbol; Trail Making A and B; Rey Auditory Learning Immediate and Delayed Recall and Recognition. For these 10 measures, single effects (no interaction) were supported (I(2) = 0%-8%) and Random and Fixed models yielded similar results. No group differences were found for Corsi Blocks Forward or Wisconsin Cart Sorting Test Categories Achieved, or Perseveration. Effects for the Rey Complex Figure Immediate and Delayed Recall were significant, but effect size was inconclusive, given moderate to high heterogeneity and lack of consistency between Random and Fixed models. For the Paced Auditory Serial Addition Test, there was a homogeneous (I(2) = 0%) and significantly lower performance in fibromyalgia (d = -.47), but no effect in diagnostically undifferentiated pain samples, and wide variability across studies of whiplash (d = -.15 to -1.04, I(2) = 60%). CONCLUSION: The magnitude and consistency of the CP - cognition effect depended on the test, pain subgroup and study source. SUMMARY POINTS: Among tests showing a chronic pain (CP) - cognition effect, the magnitude of this association was consistently small to moderate across tests.Effect size estimation was inconclusive for Digit Span Forwards, the Paced Auditory Serial Addition Test and the Rey Complex Figure Test.Variance was too heterogeneous for testing cognitive domain specificity of the CP - cognition effect.

A review of the neuro- and systemic inflammatory responses in post concussion symptoms: Introduction of the "post-inflammatory brain syndrome" PIBS.

Post-concussion syndrome is an aggregate of symptoms that commonly present together after head injury. These symptoms, depending on definition, include headaches, dizziness, neuropsychiatric symptoms, and cognitive impairment. However, these symptoms are common, occurring frequently in non-head injured controls, leading some to question the existence of post-concussion syndrome as a unique syndrome. Therefore, some have attempted to explain post-concussion symptoms as post-traumatic stress disorder, as they share many similar symptoms and post-traumatic stress disorder does not require head injury. This explanation falls short as patients with post-concussion syndrome do not necessarily experience many key symptoms of post-traumatic stress disorder. Therefore, other explanations must be sought to explain the prevalence of post-concussion like symptoms in non-head injury patients. Many of the situations in which post-concussion syndrome like symptoms may be experienced such as infection and post-surgery are associated with systemic inflammatory responses, and even neuroinflammation. Post-concussion syndrome itself has a significant neuroinflammatory component. In this review we examine the evidence of neuroinflammation in post-concussion syndrome and the potential role systemic inflammation plays in post-concussion syndrome like symptoms. We conclude that given the overlap between these conditions and the role of inflammation in their etiologies, a new term, post-inflammatory brain syndromes (PIBS), is necessary to describe the common outcomes of many different inflammatory insults. The concept of post-concussion syndrome is in its evolution therefore, the new term post-inflammatory brain syndromes provides a better understanding of etiology of its wide-array of symptoms and the wide array of conditions they can be seen in.

Guanosine protects glial cells against 6-hydroxydopamine toxicity.

Increasing body of evidence indicates that neuron-neuroglia interaction may play a key role in determining the progression of neurodegenerative diseases including Parkinson's disease (PD), a chronic pathological condition characterized by selective loss of dopaminergic (DA) neurons in the substantia nigra. We have previously reported that guanosine (GUO) antagonizes MPP(+)-induced cytotoxicity in neuroblastoma cells and exerts neuroprotective effects against 6-hydroxydopamine (6-OHDA) and beta-amyloid-induced apoptosis of SH-SY5Y cells. In the present study we demonstrate that GUO protected C6 glioma cells, taken as a model system for astrocytes, from 6-OHDA-induced neurotoxicity. We show that GUO, either alone or in combination with 6-OHDA activated the cell survival pathways ERK and PI3K/Akt. The involvement of these signaling systems in the mechanism of the nucleoside action was strengthened by a reduction of the protective effect when glial cells were pretreated with U0126 or LY294002, the specific inhibitors of MEK1/2 and PI3K, respectively. Since the protective effect on glial cell death of GUO was not affected by pretreatment with a cocktail of nucleoside transporter blockers, GUO transport and its intracellular accumulation were not at play in our in vitro model of PD. This fits well with our data which pointed to the presence of specific binding sites for GUO on rat brain membranes. On the whole, the results described in the present study, along with our recent evidence showing that GUO when administered to rats via intraperitoneal injection is able to reach the brain and with previous data indicating that it stimulates the release of neurotrophic factors, suggest that GUO, a natural compound, by acting at the glial level could be a promising agent to be tested against neurodegeneration.

Postanoxic myoclonus: two case presentations and review of medical management.

Postanoxic myoclonus is a rare manifestation after an anoxic event, with fewer than 150 cases reported in the literature. The condition is characterized by myoclonic jerks, which are worse on action than at rest, and postural lapses, ataxia, and dysarthria. The disability caused by postanoxic myoclonus can be profound, and treatment in the rehabilitation setting is exceptionally challenging. We present 2 patients who suffered from postanoxic myoclonus after an anoxic event, both of whom were successfully treated with a combination of levetiracetam, valproic acid, and clonazepam. These cases act as a framework for discussing the management of postanoxic myoclonus in the clinical setting.