Efficacy of Amantadine Treatment on Symptoms and Neurocognitive Performance Among Adolescents Following Sports-Related Concussion

The evolving pathophysiology of TBI and the advantages of temporally-guided combination therapies

Several clinical and experimental studies have demonstrated that traumatic brain injury (TBI) activates cascades of biochemical, molecular, structural, and pathological changes in the brain. These changes combine to contribute to the various outcomes observed after TBI. Given the breadth and complexity of changes, combination treatments may be an effective approach for targeting multiple detrimental pathways to yield meaningful improvements. In order to identify targets for therapy development, the temporally evolving pathophysiology of TBI needs to be elucidated in detail at both the cellular and molecular levels, as it has been shown that the mechanisms contributing to cognitive dysfunction change over time. Thus, a combination of individual mechanism-based therapies is likely to be effective when maintained based on the time courses of the cellular and molecular changes being targeted. In this review, we will discuss the temporal changes of some of the key clinical pathologies of human TBI, the underlying cellular and molecular mechanisms, and the results from preclinical and clinical studies aimed at mitigating their consequences. As most of the pathological events that occur after TBI are likely to have subsided in the chronic stage of the disease, combination treatments aimed at attenuating chronic conditions such as cognitive dysfunction may not require the initiation of individual treatments at a specific time. We propose that a combination of acute, subacute, and chronic interventions may be necessary to maximally improve health-related quality of life (HRQoL) for persons who have sustained a TBI.

Graded exposure therapy for adults with persistent symptoms after mTBI: A historical comparison study

Fear avoidance behaviour is associated with slow recovery from mild traumatic brain injury (mTBI). This study is a preliminary evaluation of graded exposure therapy (GET), which directly targets fear avoidance behaviour, for reducing post-concussion symptoms (PCS) and disability following mTBI. In a historical comparison design, we compared two groups from independent randomized trials. The GET + UC group (N = 34) received GET (delivered over 16 videoconference sessions) in addition to usual care (UC). The historical comparison group (N = 71) received UC only. PCS severity (Rivermead Post Concussion Symptoms Questionnaire; RPQ) and disability (World Health Organization Disability Assessment Schedule; WHODAS 2.0 12-item) were measured at clinic intake (M = 2.7, SD = 1.1 months after injury) and again at M = 4.9 (SD = 1.1) months after injury. Between-group differences were estimated using linear mixed effects regression, with a sensitivity analysis controlling for injury-to-assessment intervals. The estimated average change on the RPQ was -14.3 in the GET + UC group and -5.3 in the UC group. The estimated average change on the WHODAS was -5.3 in the GET + UC group and -3.2 in the UC group. Between-group differences post-treatment were -5.3 on the RPQ and -1.5 on the WHODAS. Treatment effects were larger in sensitivity analyses. Findings suggest that a randomized controlled trial is warranted.

Social Determinants of Health and Health Equity in the Treatment and Rehabilitation of Sport-Related Concussion: A Content Analysis of Intervention Research and Call-To-Action

This review was designed to (1) determine the extent to which the clinical science on sport-related concussion treatment and rehabilitation has considered social determinants of health (SDoH) or health equity and (2) offer recommendations to enhance the incorporation of SDoH and health equity in concussion treatment research and clinical care. The Concussion in Sport Group consensus statement (2023) was informed by two systematic reviews examining prescribed rest or exercise following concussion and targeted interventions to facilitate concussion recovery. We examined 31 studies, including 2,698 participants, from those two reviews. Race (k = 6; 19.4%) and ethnicity (k = 4; 12.9%) of the study samples were usually not reported. Four studies examined ethnicity (i.e., Hispanic), exclusively as a demographic category. Five studies (16.1%) examined race as a demographic category. Three studies (9.7%) examined socioeconomic status (SES; measured as household income) as a demographic category/sample descriptor and one study (3.2%) examined SES in-depth, by testing whether the treatment and control groups differed by SES. Five studies examined an SDoH domain in a descriptive manner and four studies in an inferential/intentional manner. No study mentioned SDoH, health equity, or disparities by name. Many studies (61.3%) excluded participants based on demographic, sociocultural, or health factors, primarily due to language proficiency. The new consensus statement includes recommendations for concussion treatment and rehabilitation that rely on an evidence base that has not included SDoH or studies addressing health equity. Researchers are encouraged to design treatment and rehabilitation studies that focus specifically on underrepresented groups to determine if they have specific and unique treatment and rehabilitation needs, whether certain practical modifications to treatment protocols might be necessary, and whether completion rates and treatment adherence and response are similar.

Amantadine for Traumatic Brain Injury-Supporting Evidence and Mode of Action

Traumatic brain injury (TBI) is an important global clinical issue, requiring not only prevention but also effective treatment. Following TBI, diverse parallel and intertwined pathological mechanisms affecting biochemical, neurochemical, and inflammatory pathways can have a severe impact on the patient's quality of life. The current review summarizes the evidence for the utility of amantadine in TBI in connection to its mechanism of action. Amantadine, the drug combining multiple mechanisms of action, may offer both neuroprotective and neuroactivating effects in TBI patients. Indeed, the use of amantadine in TBI has been encouraged by several clinical practice guidelines/recommendations. Amantadine is also available as an infusion, which may be of particular benefit in unconscious patients with TBI due to immediate delivery to the central nervous system and the possibility of precise dosing. In other situations, orally administered amantadine may be used. There are several questions that remain to be addressed: can amantadine be effective in disorders of consciousness requiring long-term treatment and in combination with drugs approved for the treatment of TBI? Do the observed beneficial effects of amantadine extend to disorders of consciousness due to factors other than TBI? Well-controlled clinical studies are warranted to ultimately confirm its utility in the TBI and provide answers to these questions.

Time-Dependent Long-Term Effect of Memantine following Repetitive Mild Traumatic Brain Injury

Repetitive mild traumatic brain injury (rmTBI, e.g., sports concussions) may be associated with both acute and chronic symptoms and neurological changes. Despite the common occurrence of these injuries, therapeutic strategies are limited. One potentially promising approach is N-methyl-D-aspartate receptor (NMDAR) blockade to alleviate the effects of post-injury glutamatergic excitotoxicity. Initial pre-clinical work using the NMDAR antagonist, memantine, suggests that immediate treatment following rmTBI improves a variety of acute outcomes. It remains unclear (1) whether acute memantine treatment has long-term benefits and (2) whether delayed treatment following rmTBI is beneficial, which are both clinically relevant concerns. To test this, animals were subjected to rmTBI via a weight drop model with rotational acceleration (five hits in 5 days) and randomized to memantine treatment immediately, 3 months, or 6 months post-injury, with a treatment duration of one month. Behavioral outcomes were assessed at 1, 4, and 7 months post-injury. Neuropathological outcomes were characterized at 7 months post-injury. We observed chronic changes in behavior (anxiety-like behavior, motor coordination, spatial learning, and memory), as well as neuroinflammation (microglia, astrocytes) and tau phosphorylation (T231). Memantine treatment, either immediately or 6 months post-injury, appears to confer greater rescue of neuroinflammatory changes (microglia) than vehicle or treatment at the 3-month time point. Although memantine is already being prescribed chronically to address persistent symptoms associated with rmTBI, this study represents the first evidence of which we are aware to suggest a small but durable effect of memantine treatment in mild, concussive injuries. This effect suggests that memantine, although potentially beneficial, is insufficient to treat all aspects of rmTBI alone and should be combined with other therapeutic agents in a multi-therapy approach, with attention given to the timing of treatment.

Assessing the benefits and risks of amantadine for irritability and aggression after traumatic brain injury

OBJECTIVE

To quantify the benefits versus harms of amantadine in the treatment of irritability and aggression following traumatic brain injury.

METHODS

Secondary outcome data from a randomized controlled multisite trial of amantadine 100 mg twice daily were used to calculate number-needed-to-treat (NNT). Given prior findings of positive clinician-perceived effects and low incidence of adverse events, we hypothesized low number-needed-to-treat for benefit (NNTB; high benefit) and high number-needed-to-treat for harm (NNTH; low risk) based on the clinician ratings, supporting the use of amantadine in clinical practice. Specifically, NNTB values were calculated using number of individuals with improvement on the Clinician Global Impressions-Global Improvement scale (GI). NNTH values were computed using number of individuals with worsening on the GI and experiencing serious and any adverse events.

RESULTS

Based on clinician ratings, on average for every six patients treated with amantadine rather than placebo, one extra patient would be expected to improve (NNTB = 6.4; 95% confidence interval [CI]: [3.3-76.8]). More participants in the placebo group worsened than in the amantadine group, but the result was not statistically significant (NNTH = -92.4; 95% CI: [NNTB -32.9 to infinity to NNTH -19.2]). The amantadine and placebo groups did not differ on the numbers of adverse events experienced during the trial.

CONCLUSION

Clinician ratings suggest modest benefit of amantadine 100 mg twice daily with low risk to appropriately selected patients with adequate renal clearance. Thus, amantadine should be considered a treatment option for the experienced brain injury clinician. These data may support treatment decisions when a pharmaceutical agent is being considered to control irritability/aggression.

mTBI Biological Biomarkers as Predictors of Postconcussion Syndrome-Review

Postconcussion syndrome (PCS) is one of the leading complications that may appear in patients after mild head trauma. Every day, thousands of people, regardless of age, gender, and race, are diagnosed in emergency departments due to head injuries. Traumatic Brain Injury (TBI) is a significant public health problem, impacting an estimated 1.5 million people in the United States and up to 69 million people worldwide each year, with 80% of these cases being mild. An analysis of the available research and a systematic review were conducted to search for a solution to predicting the occurrence of postconcussion syndrome. Particular biomarkers that can be examined upon admission to the emergency department after head injury were found as possible predictive factors of PCS development. Setting one unequivocal definition of PCS is still a challenge that causes inconsistent results. Neuron Specific Enolase (NSE), Glial Fibrillary Acidic Protein (GFAP), Ubiquitin C-terminal Hydrolase-L1 (UCH-L1), Serum Protein 100 B (s100B), and tau protein are found to be the best predictors of PCS development. The presence of all mentioned biomarkers is confirmed in severe TBI. All mentioned biomarkers are used as predictors of PCS. A combined examination of NSE, GFAP, UCH-1, S100B, and tau protein should be performed to detect mTBI and predict the development of PCS.

Serotonin Syndrome Precipitated by Amantadine in a Patient With Persistent Post Concussive Symptoms - A Case Report

Symptoms after mild traumatic brain injury (MTBI) can persist for greater than 1 month in up to 20% of individuals, yet there are no current medications approved by the Food and Drug Administration for treatment of specific concussion related sequelae. Amantadine, a dopamine agonist and N-Methyl-D-aspartate antagonist, is increasingly being used as a treatment option for individuals with traumatic brain injury across the spectrum of injury severity. This case report describes a 22-year-old individual who sustained an MTBI without loss of consciousness or post-traumatic amnesia after striking their head against a metal cabinet. The individual was referred to an interdisciplinary outpatient brain rehabilitation program secondary to persistent symptoms after MTBI, was prescribed amantadine for post-traumatic headache 97 days after injury, and subsequently developed symptoms of serotonin syndrome (SS) within 10 days of medication initiation. While SS caused by amantadine has been described in individuals with renal failure, this case report is the first to describe amantadine precipitating SS - confirmed by a validated diagnostic criterion and successfully treated with lorazepam and cyproheptadine - in a patient with normal renal function already on duloxetine, bupropion, and gabapentin. This case report is important in elucidating potential contributions of amantadine to the development of SS and highlighting the important role clinicians have in assessing for polypharmacy when prescribing amantadine for individuals with traumatic and acquired brain injuries.

Current evidence for pharmacological management of pediatric concussion: a systematic review

PURPOSE

Mild traumatic brain injury (mTBI) is a global public health problem and its current management is limited to rest and symptom management. Despite frequent use of drugs for symptom control, there is a lack of consensus on the optimal pharmacological management of post-concussive symptoms. We reviewed the relevant literature to compile the evidence about the pharmaceutical management of pediatric mTBI.

METHODS

We performed a systematic review of the literature available in PubMed, Cochrane CENTRAL, and ClinicalTrials.Gov as well as through citation tracing. A modified PICO framework was used for the construction of search strategy and eligibility criteria. Risk of bias was assessed using RoB-2 tool for randomized and ROBINS-I for non-randomized studies.

RESULTS

A total of 6260 articles were screened for eligibility. After exclusions, a total of 88 articles received full text review. A total of 15 reports representing 13 studies (5 randomized clinical trials, 1 prospective randomized cohort study, 1 prospective cohort study, and 6 retrospective cohort studies) met the eligibility criteria and were included in the review. We identified 16 pharmacological interventions in a total of 931 pediatric patients with mTBI. Amytriptiline (n = 4), ondansetron (n = 3), melatonin (n = 3), metoclopramide (n = 2), magnesium (n = 2), and topiramate (n = 2) were investigated in multiple studies. All RCTs were relatively of small size (n ≤ 33/group).

CONCLUSION

The available evidence supporting pharmacological intervention in pediatric mild traumatic brain injury is scarce. We propose a framework to facilitate future collaborative research efforts to test and validate various pharmacological interventions for acute and persistent post-concussive symptoms in children.

Targeted interventions and their effect on recovery in children, adolescents and adults who have sustained a sport-related concussion: a systematic review

OBJECTIVES

We evaluated interventions to facilitate recovery in children, adolescents and adults with a sport-related concussion (SRC).

DESIGN

Systematic review including risk of bias (modified Scottish Intercollegiate Guidelines Network tool).

DATA SOURCES

MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Embase, APA PsycINFO, Cochrane Central Register of Controlled Trials, CINAHL Plus with Full Text, SPORTDiscus and Scopus searched until March 2022.

STUDY ELIGIBILITY CRITERIA

(1) Original research including randomised controlled trials (RCTs), quasi-experimental designs, cohort, comparative effectiveness studies; (2) focus on SRC; (3) English; (4) peer-reviewed and (5) evaluated treatment.

RESULTS

6533 studies were screened, 154 full texts reviewed and 13 met inclusion (10 RCTs, 1 quasi-experimental and 2 cohort studies; 1 high-quality study, 7 acceptable and 5 at high risk of bias). Interventions, comparisons, timing and outcomes varied, precluding meta-analysis. For adolescents and adults with dizziness, neck pain and/or headaches >10 days following concussion, individualised cervicovestibular rehabilitation may decrease time to return to sport compared with rest followed by gradual exertion (HR 3.91 (95% CI 1.34 to 11.34)) and when compared with a subtherapeutic intervention (HR 2.91 (95% CI 1.01 to 8.43)). For adolescents with vestibular symptoms/impairments, vestibular rehabilitation may decrease time to medical clearance (vestibular rehab group 50.2 days (95% CI 39.9 to 60.4) compared with control 58.4 (95% CI 41.7 to 75.3) days). For adolescents with persisting symptoms >30 days, active rehabilitation and collaborative care may decrease symptoms.

CONCLUSIONS

Cervicovestibular rehabilitation is recommended for adolescents and adults with dizziness, neck pain and/or headaches for >10 days. Vestibular rehabilitation (for adolescents with dizziness/vestibular impairments >5 days) and active rehabilitation and/or collaborative care (for adolescents with persisting symptoms >30 days) may be of benefit.

N-methyl-D-aspartate receptor antagonists in improving cognitive deficits following traumatic brain injury: a systematic review

OBJECTIVE

To review the role of N-methyl-D-aspartate receptor (NMDAR) antagonists in managing post-TBI cognitive deficits.

METHODS

A search of PubMed, Embase, and Cochrane was conducted on Jan 12, 2021 without publication date or language restriction.

RESULTS

Forty-seven studies were included, involving 20 (42.6%) randomized controlled trials. Four (8.5%) studies had a low risk of bias (RoB), while 34 (72.3%) had unclear and nine (19.2%) had high RoB. Six NMDAR antagonists had been investigated: amantadine (n = 32), memantine (n = 4), magnesium (n = 4), traxoprodil (n = 3), selfotel (n = 2), and dextromethorphan (n = 2).

CONCLUSION

Although some benefits were observed, there are still some concerns regarding the efficacy and safety of NMDAR antagonists in improving post-TBI cognitive deficits. Further research is required to examine whether (i) these agents, notably amantadine, could accelerate cognitive improvement and shorten the hospital stay, (ii) these agents affect different cognitive domains/subdomains in the same direction, (iii) an optimal therapeutic time window exists, (iv) a member of this drug class can be proved to be effective without interfering in non-excitotoxic actions of glutamate, (v) they can be more effective as part of combination therapies or in particular subgroups of patients with TBI.

Prescribing Patterns of Amantadine During Pediatric Inpatient Rehabilitation After Traumatic Brain Injury: A Multicentered Retrospective Review From the Pediatric Brain Injury Consortium

OBJECTIVES

To describe dosing practices for amantadine hydrochloride and related adverse effects among children and young adults with traumatic brain injury (TBI) admitted to pediatric inpatient rehabilitation units.

SETTING

Eight pediatric acute inpatient rehabilitation units located throughout the United States comprising the Pediatric Brain Injury Consortium.

PARTICIPANTS

Two-hundred thirty-four children and young adults aged 2 months to 21 years with TBI.

DESIGN

Retrospective data revie.

MAIN OUTCOME MEASURES

Demographic variables associated with the use of amantadine, amantadine dose, and reported adverse effects.

RESULTS

Forty-nine patients (21%) aged 0.9 to 20 years received amantadine during inpatient rehabilitation. Forty-five percent of patients admitted to inpatient rehabilitation with a disorder of consciousness (DoC) were treated with amantadine, while 14% of children admitted with higher levels of functioning received amantadine. Children with DoC who were not treated with amantadine were younger than those with DoC who received amantadine (median 3.0 vs 11.6 years, P = .008). Recorded doses of amantadine ranged from 0.7 to 13.5 mg/kg/d; the highest total daily dose was 400 mg/d. Adverse effects were reported in 8 patients (16%); nausea/abdominal discomfort and agitation were most common, each reported in 3 patients. The highest reported dose without an adverse effect was 10.1 mg/kg/d.

CONCLUSION

During pediatric inpatient rehabilitation, amantadine was prescribed to children across a range of ages and injury severity and was most commonly prescribed to older children with DoC. Dosing varied widely, with weight-based dosing for younger/smaller children at both lower and higher doses than what had been previously reported. Prospective studies are needed to characterize the safety and tolerability of higher amantadine doses and optimize amantadine dosing parameters for children with TBI.

Current Clinical Trials in Traumatic Brain Injury

Traumatic brain injury (TBI) is one of the leading causes of morbidity, disability and mortality across all age groups globally. Currently, only palliative treatments exist, but these are suboptimal and do little to combat the progressive damage to the brain that occurs after a TBI. However, multiple experimental treatments are currently available that target the primary and secondary biochemical and cellular changes that occur after a TBI. Some of these drugs have progressed to clinical trials and are currently being evaluated for their therapeutic benefits in TBI patients. The aim of this study was to identify which drugs are currently being evaluated in clinical trials for TBI. A search of ClinicalTrials.gov was performed on 3 December 2021 and all clinical trials that mentioned “TBI” OR “traumatic brain injury” AND “drug” were searched, revealing 362 registered trials. Of the trials, 46 were excluded due to the drug not being mentioned, leaving 138 that were completed and 116 that were withdrawn. Although the studies included 267,298 TBI patients, the average number of patients per study was 865 with a range of 5–200,000. Of the completed studies, 125 different drugs were tested in TBI patients but only 7 drugs were used in more than three studies, including amantadine, botulinum toxin A and tranexamic acid (TXA). However, previous clinical studies using these seven drugs showed variable results. The current study concludes that clinical trials in TBI have to be carefully conducted so as to reduce variability across studies, since the severity of TBI and timing of therapeutic interventions were key aspects of trial success.

Supramolecular Thermo-Contracting Adhesive Hydrogel with Self-Removability Simultaneously Enhancing Noninvasive Wound Closure and MRSA-Infected Wound Healing

Conventional wound closure and dressing are two crucial, time-consuming but isolated principles in wound care. Even though tissue adhesive opens a new era for wound closure, the method and biomaterial that can simultaneously achieve noninvasive wound closure and promote wound healing are highly appreciated. Herein, a novel supramolecular poly(N-isopropylacrylamide) hybrid hydrogel dressing composed of quaternized chitosan-graft-β-cyclodextrin, adenine, and polypyrrole nanotubes via host-guest interaction and hydrogen bonds is developed. The hydrogel demonstrates thermal contraction of 47% remaining area after 2 h at 37 ℃ and tissue adhesion of 5.74 kPa, which are essential for noninvasive wound closure, and multiple mechanical and biological properties including suitable mechanical properties, self-healing, on-demand removal, antioxidant, hemostasis, and photothermal/intrinsic antibacterial activity (higher 99% killing ratio within 5 min after irradiation). In both full-thickness skin incision and excision wound models, the hydrogel reveals significant wound closure after 24 h post-surgery. In acute and methicillin-resistant Staphylococcus aureus-infected wound and photothermal/intrinsic antibacterial activity assays, wounds treated with the hydrogel demonstrate enhanced wound healing with rapid wound closure rate, mild inflammatory response, advanced angiogenesis, and well-arranged collagen fibers. Altogether, the results indicate the hydrogel is promising in synchronously noninvasive wound closure and enhanced wound healing.

Neuropsychological and neuropsychiatric recovery from mild traumatic brain injury

PURPOSE OF REVIEW

Mild traumatic brain injury (mTBI) is a significant public health concern for children. This review summarizes recent literature on early symptoms and neuropsychiatric and neuropsychological outcomes following pediatric mTBI and highlights factors that predict prolonged recovery. Evidence-based recommendations for assessment and treatment are also discussed.

RECENT FINDINGS

Whereas most children recover within 1 month after mTBI, 10-30% of children experience lingering neuropsychiatric or neuropsychological symptoms 3 months or more after injury. For the subset who experience prolonged recovery, new or worsening emotional and behavioral symptoms are the most frequent concerns. Recent research has suggested that specific factors, including preinjury mental health concerns, female sex, and family characteristics, are associated with increased risk of experiencing prolonged recovery. Early management includes reassurance, brief rest (1-3 days), and gradual return to typical activities. When symptoms linger for more than 4 weeks, evaluation in a specialty clinic is recommended and multimodal therapies are considered. Active recovery models, which include gradual return to aerobic exercise and cognitive behavioral approaches, are promising for the management of prolonged symptoms.

SUMMARY

A minority of children with mTBI experience prolonged neuropsychiatric or neuropsychological concerns. While our understanding of pediatric mTBI is growing, and recommendations for assessment and management have been developed, many gaps remain.

Assessment of the effect of amantadine in patients with traumatic brain injury: A meta-analysis

BACKGROUND

Traumatic brain injury is a global burden. We aimed to perform a meta-analysis to determine the efficacy of amantadine for cognitive performance after traumatic brain injury.

METHODS

The systematic review was prospectively registered on the International Prospective Register of Systematic Reviews website under the registration number CRD42017080044. We used Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines to report the steps of meta-analysis. The search included electronic databases (PubMed, PsycINFO, Embase, Cochrane Library databases, CENTRAL, ProQuest and ClinicalTrials.gov trial registry). Critical care medicine journals and clinical neurology specialty were searched using www.scimagojr.com. There was no publication date restriction. Two authors assessed studies' relevance and extracted data. Studies were assessed for quality using the Cochrane risk of bias tool. Data were analyzed using Comprehensive Meta-analysis Program versions 2.0 and 3.0.

RESULTS

Twenty-six studies out of 3,440 records were included in the systematic review, of which only 14 clinical trials and 6 observational studies were included in the meta-analysis. Amantadine significantly enhanced the cognitive function relative to control group (mean difference [MD], 0.50; 95% confidence interval [CI], 0.33-0.66; p < 0.001, 16 studies, 1,127 participants, low certainty evidence). Consistent significant difference in favor of amantadine relative to control group was found (MD of 0.79 [95% CI, 0.34-1.24], very low certainty evidence, for cohort studies vs. MD of 0.40 [95% CI, 0.25-0.56], moderate certainty evidence, for RCTS). Starting amantadine in the first week after TBI had a significant effect on improving cognitive function (MD, 0.97; 95% CI, 0.45-1.49; 16 studies, 1,127 participants, low certainty). Amantadine showed a better effect when administered for less than 1 month (MD, 0.83; 95% CI, 0.56-1.11; low certainty) and to patients below 18 years of age (MD, 0.66; 95% CI, 0.32-0.99; low certainty) or to patients with less severe traumatic brain injury (MD, 0.40; 95% CI, 0.18-0.62; low certainty). No statistically significant difference existed between amantadine and the control concerning the adverse events (OR, 1.74; 95% CI, 0.88-3.44; p = 0.11, moderate certainty). Metaregression of the different clinical parameters, which are onset of treatment, age, and severity of traumatic brain injury, showed a statistically significant relation between onset of treatment and the effect size of amantadine. The relation between the other two parameters and the effect size of amantadine showed a marginal statistical significance.

CONCLUSION

Amantadine may improve the cognitive function when used after TBI. Further research with high validity is needed to reach a solid conclusion about the use of amantadine in traumatic brain injury.

LEVEL OF EVIDENCE

Systematic review/meta-analysis, level III.

Acetylcholinesterase inhibitors to enhance recovery from traumatic brain injury: a comprehensive review and case series

OBJECTIVE

Acetylcholinesterase inhibitors (AChEIs) are used off-label, in both adult and pediatric patients, to help further neuro-recovery after traumatic brain injury (TBI). Evidence is limited and piecemeal. This review describes how TBI affects the cholinergic system and consolidates evidence supporting or refuting the use of AChEIs following TBI.

METHODS

NCBI MEDLINE search included all articles published through March 2021 on AChEI use in acute and post-acute adult TBI rehabilitation (treatment began <90 days or ≥90 days since injury, respectively), and in pediatric TBI rehabilitation. Further, we checked ClinicalTrials.gov for ongoing trials using AChEIs for TBI rehabilitation in the United States.

RESULTS

27 original articles from NCBI Medline, published through March 2021, were included. The use of AChEIs following TBI in acute and post-acute rehabilitation settings, in both adult and pediatric patients, along with medication side effects, is discussed.

CONCLUSIONS

Most studies showed benefits with only moderate effect sizes because of small sample sizes. Reported side effects are minimal and stop soon after AChEIs is discontinued. Conclusions are limited by paucity of research; but fortunately, a large randomized controlled trial is ongoing, and more are needed to truly determine the efficacy of AChEIs in helping with recovery from TBI.

Management of Concussion and Persistent Post-Concussive Symptoms for Neurologists

PURPOSE OF REVIEW

Concussion is a complex injury that may present as a variety of clinical profiles, which can overlap and reinforce one another. This review summarizes the medical management of patients with concussion and persistent post-concussive symptoms (PPCS).

RECENT FINDINGS

Management of concussion and PPCS relies on identifying underlying symptom generators. Treatment options include sub-symptom threshold aerobic exercise, cervical physical therapy, vestibular therapy, vision therapy, cognitive rehabilitation, cognitive behavioral therapy, pharmacological management, or a combination of treatments. Evidence-based treatments have emerged to treat post-concussion symptom generators for sport-related concussion and for patients with PPCS.

Low-Dose Ionizing Radiation Therapy: A Novel Treatment for Post-Concussion Syndrome?

A subset of victims who experience concussion suffer from persistent symptoms spanning months to years post-injury, termed post-concussion syndrome (PCS). Problematically, there is lack of consensus for the treatment of PCS. Concussion injury involves a neurometabolic cascade leading to oxidative stress and neuroinflammation which parallels the oxidative stress loading occuring from age-related neurodegenerative conditions. Historical and recent evidence has emerged showing the efficacy of low-dose radiation therapy for many human diseases including neurodegenerative diseases such as Alzhiemer’s disease (AD). Due to the pathognomonic similarities of oxidative stress and neuroinflammation involved in PCS and neurodegenerative disease, treatments that prove successful for neurodegenerative disease may prove successful for PCS. Recently, low-dose ionizing radiation therapy (LDIR) has been documented to show a reversal of many symptoms in AD, including improved cognition. LDIR is thought to induce a switching from proinflammatory M1 phenotype to an anti-inflammatory M2 phenotype. In other words, a continual upregulation of the adaptive protection systems via LDIR induces health enhancement. It is hypothesized LDIR treatment for PCS would mimic that seen from early evidence of LDIR treatment of AD patients who suffer from similar oxidative stress loading. We propose the application of LDIR is a promising, untapped treatment for PCS.

Stimulant Therapy Utilization for Neurocognitive Deficits in Mild Traumatic Brain Injury

CONTEXT

There are 3.8 million mild traumatic brain injuries (mTBIs) that occur each year in the United States. Many are left with prolonged life-altering neurocognitive deficits, including difficulties in attention, concentration, mental fatigue, and distractibility. With extensive data on the safety and efficacy of stimulant medications in treating attention deficit, concentration difficulties and distractibility seen with attention deficit disorder, it is not surprising that interest continues regarding the application of stimulant medications for the persistent neurocognitive deficits in some mTBIs.

EVIDENCE ACQUISITION

Studies were extracted from PubMed based on the topics of neurocognitive impairment, mTBI, stimulant use in mTBI, stimulants, and the association between attention deficit/hyperactivity disorder and mTBI. The search criteria included a date range of 1999 to 2020 in the English language.

STUDY DESIGN

Literature review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Currently, there is very limited literature, and no guidelines for evaluating the use of stimulant medication for the treatment of prolonged neurocognitive impairments due to mTBI. However, a limited number of studies have demonstrated efficacy and safety of stimulants in the treatment of neurocognitive sequelae of mTBI in the adult, pediatric, military, and athletic populations.

CONCLUSION

There is limited evidence to suggest stimulant medication may be beneficial in patients with mTBI with persistent neurocognitive symtpoms. The decision to utilize stimulant medication for mTBI patients remains physician and patient preference dependent. Given the limited encouraging data currently available, physicians may consider stimulant medication in appropriate patients to facilitate the recovery of prolonged neurocognitive deficits, while remaining cognizant of potential adverse effects.

Pharmacotherapy for Treatment of Cognitive and Neuropsychiatric Symptoms After mTBI

OBJECTIVES

Cognitive and neuropsychiatric symptoms are extremely common following mild traumatic brain injury (TBI), also known as concussion. Although most patients will recovery rapidly, a significant minority go on to experience persistent symptoms. There are currently no FDA-approved medications for treatment of cognitive and neuropsychiatric problems in the context of mild TBI, yet a number of agents are prescribed "off-label" for these complaints. Rigorous trials are lacking, but there are a number of open-label studies, and some small randomized controlled trials that support the safety and possible efficacy of pharmacotherapies in this population. Clinical trials conducted in samples with more severe brain injuries can also serve as a guide.

METHODS

Review of the literature.

RESULTS & CONCLUSIONS

There is the most support in the literature for the neurostimulant methylphenidate for treatment of mild TBI-related cognitive dysfunction, and the selective serotonin reuptake inhibitor, sertraline, for the treatment of postinjury depression. There is clearly a need for more well-designed studies to guide clinicians in selecting the appropriate medication and dose. Without clear guidance from the literature, a cautious approach of starting low and titrating slowly is recommended.

Evaluation and Management of Pediatric Concussion in the Acute Setting

ABSTRACT

Concussion, a type of mild traumatic brain injury, is a common injury encountered by providers caring for pediatric patients in the emergency department (ED) setting. Our understanding of the pathophysiologic basis for symptom and recovery trajectories for pediatric concussion continues to rapidly evolve. As this understanding changes, so do recommendations for optimal management of concussed youth. As more and more children present to EDs across the country for concussion, it is imperative that providers caring for children in these settings remain up-to-date with diagnostic recommendations and management techniques. This article will review the definition, epidemiology, pathophysiology, diagnosis, and management of pediatric concussion in the ED setting.

Role of the Dopaminergic System in the Striatum and Its Association With Functional Recovery or Rehabilitation After Brain Injury

Disabilities are estimated to occur in approximately 2% of survivors of traumatic brain injury (TBI) worldwide, and disability may persist even decades after brain injury. Facilitation or modulation of functional recovery is an important goal of rehabilitation in all patients who survive severe TBI. However, this recovery tends to vary among patients because it is affected by the biological and physical characteristics of the patients; the types, doses, and application regimens of the drugs used; and clinical indications. In clinical practice, diverse dopaminergic drugs with various dosing and application procedures are used for TBI. Previous studies have shown that dopamine (DA) neurotransmission is disrupted following moderate to severe TBI and have reported beneficial effects of drugs that affect the dopaminergic system. However, the mechanisms of action of dopaminergic drugs have not been completely clarified, partly because dopaminergic receptor activation can lead to restoration of the pathway of the corticobasal ganglia after injury in brain structures with high densities of these receptors. This review aims to provide an overview of the functionality of the dopaminergic system in the striatum and its roles in functional recovery or rehabilitation after TBI.

Rehabilitation of Concussion and Persistent Postconcussive Symptoms

Concussion and persistent postconcussive symptoms (PPCS) are encountered by clinicians in sports medicine, pediatrics, neurology, physiatry, emergency medicine, and primary care. Clinical management may require a multidisciplinary approach. This article presents a structured method for the diagnosis of concussion and PPCS in the outpatient setting, which includes a history, physical examination, and additional tests as clinically indicated to help identify underlying symptom generators. Treatment for concussion and PPCS should be individualized, based on predominant signs and symptoms, and can include subsymptom threshold aerobic exercise, cervical physical therapy, vestibulo-ocular rehabilitation, behavioral and cognitive psychotherapy, and some symptom-specific pharmacological therapies.

Amantadine: reappraisal of the timeless diamond-target updates and novel therapeutic potentials

The aim of the current review was to provide a new, in-depth insight into possible pharmacological targets of amantadine to pave the way to extending its therapeutic use to further indications beyond Parkinson's disease symptoms and viral infections. Considering amantadine's affinities in vitro and the expected concentration at targets at therapeutic doses in humans, the following primary targets seem to be most plausible: aromatic amino acids decarboxylase, glial-cell derived neurotrophic factor, sigma-1 receptors, phosphodiesterases, and nicotinic receptors. Further three targets could play a role to a lesser extent: NMDA receptors, 5-HT3 receptors, and potassium channels. Based on published clinical studies, traumatic brain injury, fatigue [e.g., in multiple sclerosis (MS)], and chorea in Huntington's disease should be regarded potential, encouraging indications. Preclinical investigations suggest amantadine's therapeutic potential in several further indications such as: depression, recovery after spinal cord injury, neuroprotection in MS, and cutaneous pain. Query in the database http://www.clinicaltrials.gov reveals research interest in several further indications: cancer, autism, cocaine abuse, MS, diabetes, attention deficit-hyperactivity disorder, obesity, and schizophrenia.

Effects of Memantine in Patients with Traumatic Brain Injury: A Systematic Review

Traumatic brain injury (TBI) affects millions of people around the world and amongst other effects, causes cognitive decline, neurodegenerative disease and increased risk of seizures and sensory disturbances. Excitotoxicity and apoptosis occur after TBI and are mediated through the N-methyl-D-aspartate (NMDA)-type glutamate receptor. Memantine is effective in blocking excessive activity of NMDA-type glutamate receptors and reduces the progression of dementia and may have benefits after TBI. Here, we performed a systematic review of the literature to evaluate whether memantine is effective in improving outcomes, including cognitive function in patients with TBI. Our search yielded only 4 randomized control trials (RCTs) that compared the effects of memantine to placebos, standard treatment protocols or piracetam. A single RCT reported that serum neuron-specific enolase (NSE) levels were significantly reduced (p = 0.009) in the memantine compared to the control group, and this coincided with reported significant day-to-day improvements in Glasgow Coma Scale (GCS) for patients receiving memantine. The remaining RCTs investigated the effects of memantine on cognitive function using 26 standardized tests for assessing cognition function. One RCT reported significant improvements in cognitive function across all domains whilst the other two RCTs, reported that patients in the memantine group underperformed in all cognitive outcome measures. This review shows that despite laboratory and clinical evidence reporting reduced serum NSE and improved GCS, supporting the existence of the neuroprotective properties, there is a lack of reported evidence from RCTs to suggest that memantine directly leads to cognitive improvements in TBI patients.

Associations Between Amantadine Usage, Gait, and Cognition in PSP: A post-hoc Analysis of the Davunetide Trial

Introduction: Amantadine anecdotally improves gait in progressive supranuclear palsy (PSP) but definitive data is lacking. We investigated associations between amantadine usage, gait, cognition, and activities of daily living in 310 subjects with PSP using data from the davunetide trial.

Method: We compared baseline demographics, PSP Rating Scale (PSPRS), Repeat Battery for the Assessment of Neuropsychological Status (RBANS), and Schwab and England Activities of Daily Living (SEADL) scores between subjects taking vs. not taking amantadine using chi-square tests for categorical variables and independent sample t-tests for continuous variables. Using the general linear model (GLM), we tested whether group status predicted total PSPRS, PSPRS-gait and midline, total RBANS, RBANS-attention, and SEADL before and after the 52-weeks follow-up.

Results: Subjects taking vs. not taking amantadine were similar at baseline, except subjects taking amantadine had a higher Clinical Global Impression (CGI) Score (p = 0.01). However, the CGI change score did not differ between groups at week 52 (p = 0.10). Using GLM models (controlling for covariates), we found that subjects taking vs. not taking amantadine did not significantly predict total PSPRS, PSPRS-gait and midline, total RBANS, RBANS-attention, or SEADL at baseline, week 52, or the change score between baseline and week 52.

Discussion: This post-hoc analysis of the davunetide trial did not find an association between amantadine and gait or cognitive measures in PSP, but was not powered to find such a difference. Future studies should still examine amantadine for symptomatic benefit in multiple PSP subtypes.

Disparities in baseline neurocognitive testing for student concussion management in Massachusetts high schools

PURPOSE

There is evidence of socioeconomic disparities with respect to the implementation of student-sports concussion laws nationally. The purpose of this study was to examine school sociodemographic characteristics associated with the provision of computerised baseline neurocognitive testing (BNT) in Massachusetts (MA) high schools, and to assess whether the scope of testing is associated with the economic status of student populations in MA.

METHODS

A cross-sectional secondary analysis of surveys conducted with MA athletic directors (n=270) was employed to investigate school characteristics associated with the provision of BNT. Correlation and regression analyses were used to assess whether the scope of testing is associated with the economic status of student populations in MA.

RESULTS

The scope of BNT was independently associated with the economic disadvantage rate (EDR) of the student population (β=-0.02, p=0.01); whether or not the school employs an athletic trainer (AT) (β=0.43, p=0.03); and school size (β=-0.54, p=0.03). In a multivariable regression model, EDR was significantly associated with the scope of baseline testing, while controlling for AT and size (β=-0.01, p=0.03, adj-R2=0.1135).

CONCLUSION

Among public high schools in MA, disparities in the provision of BNT for students are associated with the economic characteristics of the student body. Schools that have a greater proportion of low-income students are less likely to provide comprehensive BNT. The clinical implications of not receiving BNT prior to concussion may include diminished quality of postconcussive care, which can have short-term and long-term social, health-related and educational impacts.

Amantadine and memantine: a comprehensive review for acquired brain injury

This comprehensive review discusses clinical studies of patients following brain injuries (traumatic, acquired, or stroke), who have been treated with amantadine or memantine. Both amantadine and memantine are commonly used in the acute rehabilitation setting following brain injuries, despite their lack of FDA-approval for neuro-recovery. Given the broad utilization of such agents, there is a need to review the evidence supporting this common off-label prescribing. The purpose of this review is to describe the mechanisms of action for memantine and amantadine, as well as to complete a comprehensive review of the clinical uses of these agents. We included 119 original, clinical research articles from NCBI Medline, published before 2019. We focused on the domains of neuroplasticity, functional recovery, motor recovery, arousal, fatigue, insomnia, behavior, agitation, and cognition. Most of the existing research supporting the use of amantadine and memantine in recovery from brain injuries was done in very small populations, limiting the significance of conclusions. While most studies are positive; small effect sizes are usually reported, or populations are subject to bias. Furthermore, evidence is so limited that this review includes research regarding both acute and chronic acquired brain injury populations. Fortunately, reported short-term side effects generally are modest, and stop soon after amantadine/memantine is discontinued. However, responses are inconsistent, and the phenotype of responders remains elusive.

Stimulant Use in the Management of Mild Traumatic Brain Injury: A Qualitative Literature Review

Objective: Mild traumatic brain injury (mTBI) often presents with cognitive complaints including difficulty with attention and concentration. As these symptoms resemble those of ADHD, stimulants may be a potential treatment for mTBI. This review evaluates the literature on the use of stimulants for the treatment of mTBI. Method: A systematic evaluation of the literature using six databases: Ovidmedline, Pubmed, psychINFO, CINAH, Embase, and Cochrane. Broad search terms were used and studies were included that evaluate the use of stimulant and stimulant-like medications in the mTBI population. Data extracted included stimulant type and dosing, symptoms targeted, outcomes, safety and tolerability, and if the study population had ADHD. Results: Nine studies were identified that met the inclusion criteria. Immediate release methylphenidate and amantadine were used for treatment. Methylphenidate had some impact on attention, fatigue, and depression. However, due to the limited number of studies and heterogeneity of study populations, symptoms targeted, and outcome measures used, meaningful conclusions regarding the effect of stimulants in mTBI could not be made. No study evaluated for the presence of ADHD within the study population, despite stimulants being the mainstay treatment for ADHD. Conclusion: PProspective studies on the use of stimulants in mTBI, that evaluate participants for a diagnosis of ADHD, are needed.

Sport-Related Concussion Evaluation and Management

Concussion is a challenging and controversial medical diagnosis that can test even the most seasoned practitioner. Knowledge on this topic is ever evolving. It was not so long ago that grading guidelines were based on loss of consciousness and amnesia. Medicine has seen a renaissance of discovery over the past 20 years in concussion evaluation and management. A PubMed search for "concussion" between 1990 and 2000 produced just over 1000 articles and that same search including the last 18 years expands to over 10,000 publications. The most recent knowledge and recommendations are discussed based on the published evidence.

Practice Patterns in Pharmacological and Non-Pharmacological Therapies for Children with Mild Traumatic Brain Injury: A Survey of 15 Canadian and United States Centers

Given the lack of evidence regarding effective pharmacological and non-pharmacological interventions for pediatric mild traumatic brain injury (mTBI) and the resultant lack of treatment recommendations reflected in consensus guidelines, variation in the management of pediatric mTBI is to be expected. We therefore surveyed practitioners across 15 centers in the United States and Canada who care for children with pediatric mTBI to evaluate common-practice variation in the management of pediatric mTBI. The survey, developed by a panel of pediatric mTBI experts, consisted of a 10-item survey instrument regarding providers' perception of common pediatric mTBI symptoms and mTBI interventions. Surveys were distributed electronically to a convenience sample of local experts at each center. Frequencies and percentages (with confidence intervals [CI]) were determined for survey responses. One hundred and seven respondents (71% response rate) included specialists in pediatric Emergency Medicine, Sports Medicine, Neurology, Neurosurgery, Neuropsychology, Neuropsychiatry, Physical and Occupational Therapy, Physiatry/Rehabilitation, and General Pediatrics. Respondents rated headache as the most prevalently reported symptom after pediatric mTBI, followed by cognitive problems, dizziness, and irritability. Of the 65 (61%; [95% CI: 51,70]) respondents able to prescribe medications, non-steroidal anti-inflammatory medications (55%; [95% CI: 42,68]) and acetaminophen (59%; [95% CI: 46,71]) were most commonly recommended. One in five respondents reported prescribing amitriptyline for headache management after pediatric mTBI, whereas topiramate (8%; [95% CI: 3,17]) was less commonly reported. For cognitive problems, methylphenidate (11%; [95% CI: 4,21]) was used more commonly than amantadine (2%; [95% CI: 0,8]). The most common non-pharmacological interventions were rest ("always" or "often" recommended by 83% [95% CI: 63,92] of the 107 respondents), exercise (59%; [95%CI: 49,69]), vestibular therapy (42% [95%CI: 33,53]) and cervical spine exercises (29% [95%CI: 21,39]). Self-reported utilization for common pediatric mTBI interventions varied widely across our Canadian and United States consortium. Future effectiveness studies for pediatric mTBI are urgently needed to advance the evidence-based care.

Nurse practitioners' recommendations for pharmacotherapy in the management of adolescent concussion

BACKGROUND AND PURPOSE

Nurse practitioners (NPs) frequently treat acute conditions presenting in children and adolescents in the outpatient setting. No evidence-based guidance exists pertaining to the treatment of concussion with medications. The purpose of this study was to examine recommendations by NPs for pharmacotherapy of acute symptoms for adolescent concussion.

METHODS

This is a secondary analysis of data from a web-based census survey of all licensed NPs in Oregon and Washington State, where they practice as independent providers with prescriptive authority. Based on a standardized adolescent patient scenario video, NPs were asked to indicate prescription or nonprescription medication recommendations for concussion symptoms. Open-ended descriptions of medication recommendations were coded, summarized, and described.

CONCLUSIONS

In narrative text, 78.4% of the 991 respondents recommended at least one type of prescription or nonprescription medication. Prescription medications (recommended by 17.2%) included antiemetics and antimigraine medications; nonprescription medications (recommended by 75.5%) included nonsteroidal anti-inflammatory drugs, over-the-counter pain relievers, and herbal medications. Pharmacotherapy recommendations varied by NP practice setting and rurality.

IMPLICATIONS FOR PRACTICE

Nurse practitioners have full prescriptive authority in many states. No guidelines inform medication use in managing acute concussion symptoms, yet many providers recommend their use.

Review of the Management of Pediatric Post-Concussion Syndrome-a Multi-Disciplinary, Individualized Approach

PURPOSE OF REVIEW

Post-concussion syndrome (PCS), when the patient's concussion symptoms last longer than 4-6 weeks, affects 10-30% of concussion patients. PCS presents a significant source of morbidity to patients and a management challenge to providers. In this review, we present the current evidence and best management approaches for pediatric PCS.

RECENT FINDINGS

There is limited high-quality evidence in pediatric PCS. There is some evidence supporting pharmaceutical management of post-traumatic headaches, cognitive symptoms, and emotional symptoms. Vestibular-ocular dysfunction should be evaluated and managed appropriately. Neuropsychological recovery is expected, but requires appropriate attention to Return to Learn. Emotional symptoms are common in PCS and the evidence supports treatment with cognitive behavioral therapy. PCS presents a unique therapeutic challenge affecting multiple domains for patients-physical, sleep, cognitive, and emotional. Successful management of PCS requires a multi-disciplinary and individualized approach. There remains a significant need for further research, specifically looking into the outcomes and effective interventions in pediatric PCS.

Posttraumatic headache in pediatrics: an update and review

PURPOSE OF REVIEW

Headache following concussion and mild traumatic brain injury is very common in pediatrics. There is significant concern about appropriate management of acute and persistent headache following mild head injuries in children among affected youth, their families and care providers.

RECENT FINDINGS

The current article will review definitions and diagnoses of posttraumatic headache (PTHA), recent research regarding risk factors for persistence of postconcussion symptoms and headaches, current recommendations for the evaluation of youth with PTHA, recent data regarding efficacy of treatment options for PTHA, and current recommendations for the treatment of acute and persistent PTHA.

SUMMARY

PTHA is common following concussion in pediatrics. Some of the most consistent risk factors for persistent symptoms following concussion include female sex, adolescent age, prior concussion with prolonged recovery, prior headache history and high number of acute symptoms, particularly migrainous symptoms, following concussion. There are few prospective studies of the treatment of PTHA in pediatrics; however, a recent study found that short-term use of ibuprofen for those with acute PTHA following concussion may be associated with lower risk of symptoms and better function 1 week after injury. Currently complete rest or cocooning following concussion is not recommended as it may actually be associated with longer recovery time; a gradual return to cognitive and physical activity appears to be most effective strategy but more study is needed.

Neurostimulant Prescribing Patterns in Children Admitted to the Intensive Care Unit after Traumatic Brain Injury

Neurostimulant medications are commonly prescribed following traumatic brain injury (TBI) in adults; little is known about their use in children with TBI. Our objective was to analyze neurostimulant prescribing practices from 2005 to 2015 in children admitted to the intensive care unit (ICU) with TBI. We hypothesized that neurostimulant prescriptions have increased over time and are associated with older age and injury severity. A retrospective cohort study of patients age 1 month to 18 years with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) discharge diagnosis code for TBI admitted to the ICU between 2005 and 2015 in 37 pediatric hospitals included in the Pediatric Health Information System was conducted. Variables examined include patient and injury characteristics and neurostimulant medication use. Descriptive statistics and multi-variable logistic regression testing were used to determine variables associated with neurostimulant prescription. Of 30,881 patients with TBI, most were male (64%) and age 0-4 years (43%). In patients with mechanism of injury reported (n = 21,998), TBI was most frequently due to falls (36%) and motor vehicle collisions (36%). One thousand sixty-four neurostimulants were prescribed to 878 (3%) patients with 41% of prescriptions for amantadine and 38% for methylphenidate. Neurostimulants were prescribed a median (interquartile range) of 17 (8-35) days post-injury and increased over the study decade (R² = 0.806). In a multi-variable analysis, variables most strongly associated with receipt of a neurostimulant were age 14-18 years (odds ratio 5.8, 95% confidence interval [4.3,7.8]), motor vehicle collision (3.1, [2.4,4.2]), intracranial pressure (ICP) monitor (3.8, [3.1,4.5]), and mechanical ventilation (3.4, [2.7,4.3]). Use of neurostimulants following pediatric TBI is uncommon, has increased over time, and is associated with indicators of higher severity of illness. Knowledge of prescribing practices may assist in optimizing the design of efficacy and outcome studies that will inform clinical guidelines.

Managing Sports-related Concussions From Time of Injury Through Return to Play

Sports-related concussions continue to generate widespread interest. A concussion is a complex pathophysiologic process, with or without loss of consciousness, that results in a disturbance of brain function. Risk factors include age <18 years, female sex, and history of a previous concussion. A sideline physical examination with standardized assessment tools can assist diagnosis. Management for suspected concussion begins with immediate removal from play and requires clinical follow-up. Symptoms are usually self-limited and resolve within 2 to 3 weeks. Initial treatment consists of a reduction in cognitive activity and physical rest. A stepwise return-to-play protocol, taking into consideration state laws, with a gradual increase in activity until the athlete is able to perform full activity without symptoms should be followed. Neuropsychologic testing may be used as a tool in management. For prolonged concussion, physical rehabilitation or medications for headaches, mood, or sleep disturbance may be required. Education, rule changes, and equipment improvements may assist in prevention. The long-term consequences of concussions are not fully understood and merit additional research.

Amantadine Did Not Positively Impact Cognition in Chronic Traumatic Brain Injury: A Multi-Site, Randomized, Controlled Trial

Despite limited evidence to support the use of amantadine to enhance cognitive function after traumatic brain injury (TBI), the clinical use for this purpose is highly prevalent and is often based on inferred belief systems. The aim of this study was to assess effect of amantadine on cognition among individuals with a history of TBI and behavioral disturbance using a parallel-group, randomized, double-blind, placebo-controlled trial of amantadine 100 mg twice-daily versus placebo for 60 days. Included in the study were 119 individuals with two or more neuropsychological measures greater than 1 standard deviation below normative means from a larger study of 168 individuals with chronic TBI (>6 months post-injury) and irritability. Cognitive function was measured at treatment days 0, 28, and 60 with a battery of neuropsychological tests. Composite indices were generated: General Cognitive Index (included all measures), a Learning Memory Index (learning/memory measures), and Attention/Processing Speed Index (attention and executive function measures). Repeated-measures analysis of variance revealed statistically significant between-group differences favoring the placebo group at day 28 for General Cognitive Index (p = 0.002) and Learning Memory Index (p = 0.001), but not Attention/Processing Speed Index (p = 0.25), whereas no statistically significant between-group differences were found at day 60. There were no statistically significant between-group differences on adverse events. Cognitive function in individuals with chronic TBI is not improved by amantadine 100 mg twice-daily. In the first 28 days of use, amantadine may impede cognitive processing. However, the effect size was small and mean scores for both groups were generally within expectations for persons with history of complicated mild-to-severe TBI, suggesting that changes observed across assessments may not have functional significance. The use of amantadine to enhance cognitive function is not supported by these findings.

Sports-Related Concussion: Acute Management and Chronic Postconcussive Issues

Sports-related concussion (SRC) is a common problem in youth sports. Concussion may occur after a forceful hit to the body or head, resulting in transient neuropathological changes that spontaneously resolve with relative rest and activity modification in most patients. Most SRCs are effectively managed by primary care physicians and sports medicine specialists. In some cases, symptoms may persist and the child and adolescent psychiatrist may be consulted. This article reviews important background information regarding SRC and highlights a variety of pharmacologic and nonpharmacologic treatment options that consultant psychiatrists should know.

Post-Concussive Syndrome: a Focus on Post-Traumatic Headache and Related Cognitive, Psychiatric, and Sleep Issues

PURPOSE OF REVIEW

Post-traumatic headache (PTH) is a secondary headache disorder following traumatic brain injury. We sought to examine the recent literature on PTH and associated cognitive, psychiatric, and sleep conditions to understand the latest findings about the associated conditions and available screening tools, and to understand the available treatment options for PTH.

RECENT FINDINGS

Up to one third of PTH patients may have depression and about one quarter may have insomnia. Anxiety and cognitive issues are also common. While there are few studies examining abortive medications for PTH, recent studies of preventive medications examine the efficacy of topiramate, and topiramate may be better than other oral preventive medications. Other currently investigated treatments include nerve blocks, onabotulinum toxin A, transmagnetic stimulation, and behavioral therapy (biofeedback). Due to an expanded focus on and knowledge of concussion and PTH, comorbid psychiatric, cognitive, and sleep issues have become more widely acknowledged and studied. However, more high-quality studies must be conducted to examine the underlying pathophysiology of PTH and associated symptoms and to determine the most effective abortive and preventive treatment options.

Validity of the Immediate Post Concussion Assessment and Cognitive Testing (ImPACT)

BACKGROUND

The immediate post concussion assessment and cognitive testing (ImPACT) is the most widely used concussion assessment tool. Despite its popularity, it is unclear if validation studies for the ImPACT test covered all aspects of validity to support its widespread use in research and clinical practice.

OBJECTIVE

The purpose of this report is to review literature surrounding the validity and the utility of the ImPACT test.

DATA SOURCES AND APPRAISAL

A systematic review of relevant studies in PubMed, CINAHL, and PsycINFO was carried out. Studies were evaluated using the STROBE (strengthening the reporting of observational studies in epidemiology) or the STARD (standards for reporting of diagnostic accuracy) criteria.

RESULTS

The literature search yielded 5968 studies. Sixty-nine studies met the inclusion criteria and were included in the qualitative review. Although the convergent validity of ImPACT was supported, evidence of discriminant and predictive validity, diagnostic accuracy and responsiveness was inconclusive. The utility of the ImPACT test after acute symptom resolution was sparse. The review found many factors influenced the validity and utility of ImPACT scores.

CONCLUSION

Clinicians must consider the benefit of ImPACT testing for their patients on a case-by-case scenario and must take the psychometric properties of the test into account when interpreting results.

Memantine improves outcomes after repetitive traumatic brain injury

Repetitive mild traumatic brain injury (rmTBI; e.g., sports concussions) is common and results in significant cognitive impairment. Targeted therapies for rmTBI are lacking, though evidence from other injury models indicates that targeting N-methyl-d-aspartate (NMDA) receptor (NMDAR)-mediated glutamatergic toxicity might mitigate rmTBI-induced neurologic deficits. However, there is a paucity of preclinical or clinical data regarding NMDAR antagonist efficacy in the rmTBI setting. To test whether NMDAR antagonist therapy improves outcomes after rmTBI, mice were subjected to rmTBI injury (4 injuries in 4days) and randomized to treatment with the NMDA antagonist memantine or with vehicle. Functional outcomes were assessed by motor, anxiety/impulsivity and mnemonic behavioral tests. At the synaptic level, NMDAR-dependent long-term potentiation (LTP) was assessed in isolated neocortical slices. At the molecular level, the magnitude of gliosis and tau hyper-phosphorylation was tested by Western blot and immunostaining, and NMDAR subunit expression was evaluated by Western blot and polymerase chain reaction (PCR). Compared to vehicle-treated mice, memantine-treated mice had reduced tau phosphorylation at acute time points after injury, and less glial activation and LTP deficit 1 month after injury. Treatment with memantine also corresponded to normal NMDAR expression after rmTBI. No corresponding protection in behavior outcomes was observed. Here we found NMDAR antagonist therapy may improve histopathological and functional outcomes after rmTBI, though without consistent corresponding improvement in behavioral outcomes. These data raise prospects for therapeutic post-concussive NMDAR antagonism, particularly in athletes and warriors, who suffer functional impairment and neurodegenerative sequelae after multiple concussions.

Rest and treatment/rehabilitation following sport-related concussion: a systematic review

AIM OR OBJECTIVE

The objective of this systematic review was to evaluate the evidence regarding rest and active treatment/rehabilitation following sport-related concussion (SRC).

DESIGN

Systematic review.

DATA SOURCES

MEDLINE (OVID), CINAHL (EbscoHost), PsycInfo (OVID), Cochrane Central Register of Controlled Trials (OVID), SPORTDiscus (EbscoHost), EMBASE (OVID) and Proquest DissertationsandTheses Global (Proquest) were searched systematically.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies were included if they met the following criteria: (1) original research; (2) reported SRC as the diagnosis; and (3) evaluated the effect of rest or active treatment/rehabilitation. Review articles were excluded.

RESULTS

Twenty-eight studies met the inclusion criteria (9 regarding the effects of rest and 19 evaluating active treatment). The methodological quality of the literature was limited; only five randomised controlled trials (RCTs) met the eligibility criteria. Those RCTs included rest, cervical and vestibular rehabilitation, subsymptom threshold aerobic exercise and multifaceted collaborative care.

SUMMARY/CONCLUSIONS

A brief period (24-48 hours) of cognitive and physical rest is appropriate for most patients. Following this, patients should be encouraged to gradually increase activity. The exact amount and duration of rest are not yet well defined and require further investigation. The data support interventions including cervical and vestibular rehabilitation and multifaceted collaborative care. Closely monitored subsymptom threshold, submaximal exercise may be of benefit.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2016:CRD42016039570.