Neurobehavioral Effects of Amantadine After Pediatric Traumatic Brain Injury

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.

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.

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.

Does amantadine maintain function in long-established brain injury? A single case experimental design

OBJECTIVE

The role of dopamine agonist (DA) in restoring consciousness and cognition in recovery phase following acquired brain injury (ABI) is established ^(1-5). The role in later recovery is less well defined. We report a single case experimental design (SCED) trial of amantadine demonstrating improvement in function, six years following ABI.

METHOD

A scoring system based on established abilities in personal care and interaction was used to identify tasks with component actions, 34 actions in total, each ranked in terms of quality of response to a request or prompt. Actions were scored on maintenance dose amantadine; on withdrawal; and after reintroduction. Daytime sleep duration was also recorded.

RESULTS

At 3^rd and 5^th weeks post withdrawal, deterioration was noted in 27 of 34 graded activities. At 3^rd and 5^th weeks following reintroduction, all but 3 grades returned to baseline or better. Afternoon sleep duration increased from 35 to 80 minutes during withdrawal period returning towards baseline on amantadine resumption.

CONCLUSION

We believe this provides evidence for benefit of amantadine in sustaining function following ABI. The SCED model used provides a template for others to use to identify comparable change in similar trials.

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.

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.

The effects of anticholinergic medications on cognition in children: a systematic review and meta-analysis

Cognitive side effects of anticholinergic medications in older adults are well documented. Whether these poor cognitive outcomes are observed in children has not been systematically investigated. We aimed to conduct a systematic review and meta-analysis on the associations between anticholinergic medication use and cognitive performance in children. Systematic review was conducted using Medline, PsychInfo, and Embase, identifying studies testing cognitive performance relative to the presence versus absence of anticholinergic medication(s) in children. We assessed effects overall, as well as relative to drug class, potency (low and high), cognitive domain, and duration of administration. The systematic search identified 46 articles suitable for meta-analysis. For the most part, random effects meta-analyses did not identify statistically significant associations between anticholinergic exposure and cognitive performance in children; the one exception was a small effect of anticholinergic anti-depressants being associated with better cognitive function (Hedges' g = 0.24, 95% CI 0.06-0.42, p = 0.01). Anticholinergic medications do not appear to be associated with poor cognitive outcomes in children, as they do in older adults. The discrepancy in findings with older adults may be due to shorter durations of exposure in children, differences in study design (predominantly experimental studies in children rather than predominantly epidemiological in older adults), biological ageing (e.g. blood brain barrier integrity), along with less residual confounding due to minimal polypharmacy and comorbidity in children.

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.

Cocaine self-administration is increased after frontal traumatic brain injury and associated with neuroinflammation

Traumatic brain injury (TBI) has been linked to the development of numerous psychiatric diseases, including substance use disorder. However, it can be difficult to ascertain from clinical data whether the TBI is cause or consequence of increased addiction vulnerability. Surprisingly few studies have taken advantage of animal models to investigate the causal nature of this relationship. In terms of a plausible neurobiological mechanism through which TBI could magnify the risk of substance dependence, numerous studies indicate that TBI can cause widespread disruption to monoaminergic signaling in striatal regions, and also increases neuroinflammation. In the current study, male Long-Evans rats received either a mild or severe TBI centered over the frontal cortex via controlled cortical impact, and were subsequently trained to self-administer cocaine over 10 6-hour sessions. At the end of the study, markers of striatal dopaminergic function, and levels of inflammatory cytokine levels in the frontal lobes, were assessed via western blot and multiplex ELISA, respectively. There was significantly higher cocaine intake in a subset of animals with either mild or severe TBI. However, many animals within both TBI groups failed to acquire self-administration. Principal components analysis suggested that both dopaminergic and neuroinflammatory proteins were associated with overall cocaine intake, yet only an inflammatory component was associated with acquisition of self-administration, suggesting neuroinflammation may make a more substantial contribution to the likelihood of drug-taking. Should neuroinflammation play a causal role in mediating TBI-induced addiction risk, anti-inflammatory therapy may reduce the likelihood of substance abuse in TBI populations.

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.

The effects of amantadine on traumatic brain injury outcome: a double-blind, randomized, controlled, clinical trial

INTRODUCTION

Amantadine, as a dopamine receptor agonist, may stimulate and help the recovery of the nervous system after traumatic brain injury (TBI).

METHODS

We performed this study as a double-blind, randomized, controlled clinical trial with target population including all patients with TBI who scored nine or lower on the Glasgow Coma Scale (GCS), admitted to our hospital between January 2013 and April 2014. The protocol included administration of the drug (placebo or amantadine) for 6 weeks and patient evaluation using the GCS and FOUR score on the first, third and seventh days after the drug was started. After 6 months from starting study drug, the patients were evaluated on the Mini-Mental State Examination, Glasgow Outcome Study, Disability Rating Scale and Karnofsky Performance Scale.

RESULTS

We included 40 patients in the study. The mean age of the patients was 36.77 ± 18.21. As an only important finding, the amantadine group registered an important rise between the first and the seventh day of study drug (∆GCS7-GCS1) with p-value = 0.044.

CONCLUSION

Based on our findings during the first week and the 6 months (since starting drug) follow-ups, prescribing amantadine did not lead to reportable effects on the patients' level of consciousness, memory, disability, cognition, mortality and performance.

Amantadine Therapy in Traumatic Brain Injury Patients

Objective:

To review literature on amantadine therapy in patients with traumatic brain injury (TBI).

Data Sources:

MEDLINE (1966–March 2006), EMBASE (1974–March 2006), BIOSIS (1969–March 2006), and International Pharmaceutical Abstracts (1970–March 2006) were searched to identify papers on the clinical outcomes of patients with TBI treated with amantadine. A bibliographic search was also performed.

Study Selection and Data Extraction:

Papers were excluded if they were not published in English, if they included patients less than 16 years old, or if they included patients in whom the effects of multiple medications, rather than amantadine alone, were studied. Reports were categorized according to the time of initiation of amantadine following the injury.

Data Synthesis:

Reports examining early initiation of amantadine suggest a possible benefit for treatment of decreased responsiveness and functional recovery. One report examining late initiation of amantadine failed to demonstrate benefit in the treatment of motor impairment, while 2 reports suggested possible improvement of functional recovery. Finally, reports examining late initiation of amantadine in the treatment of cognitive and behavioral therapy demonstrated possible benefit.

Conclusions:

Further investigation is needed before either early or late initiation of amantadine can be recommended for treatment of decreased responsiveness and functional recovery. However, while additional research is conducted, late initiation of amantadine can be considered an option for the treatment of cognitive and behavioral impairments in patients with TBI.

The Diagnosis and Management of Concussion in Children and Adolescents

BACKGROUND

Concussion is a complex brain injury that results in more than 100,000 emergency department visits for school-aged children each year in the United States. All 50 US states have passed concussion legislation designed to promote safety in youth sports. Most of these laws require medical clearance by a licensed health care provider before returning to sport, which may have contributed to an increase in pediatric subspecialty referrals, particularly referrals to the child neurologist.

METHODS

We reviewed the literature on pediatric concussion.

RESULTS

This review summarizes the current knowledge and recommendations for concussion diagnosis and management in children and adolescents, athletes and nonathletes. It highlights concussion epidemiology, pathophysiology, advances in neuroimaging, and potential health risks including second impact syndrome and chronic traumatic encephalopathy. It also underscores clinical areas where evidence is lacking.

CONCLUSIONS

The diagnosis and management of concussion requires specific considerations in children. Further concussion research must be done to minimize injury risk and to optimize medical care for this common problem.

Contribution of rating scales to intervention for executive dysfunction

Executive dysfunction is present in children, adolescents, and adults with a wide range of clinical conditions. A growing body of literature has demonstrated the usefulness of rating scales designed to gauge executive functioning in everyday life. In this article, we discuss evidence supporting the use of such rating scales to assess intervention outcome, how they may inform development of interventions, and how comparing rater perspectives can assess awareness of cognitive dysfunction. We provide an example of how an executive function rating scale helped define intervention targets and measured outcomes in a recently published real-world intervention for children with autism spectrum disorder. Rating scales of executive function provide valuable information with respect to treatment planning and assessment of intervention outcome.

The use of stimulant medication to treat neurocognitive deficits in patients with pediatric cancer, traumatic brain injury, and sickle cell disease: a review

Several chronic health conditions of childhood, including pediatric cancers, traumatic brain injury (TBI), and sickle cell disease (SCD) are associated with significant neurocognitive impairments that can compromise educational attainment and future vocational opportunities. The prominence of attentional deficits as part of the neurocognitive sequelae associated with each of these conditions has led some researchers to draw parallels with another chronic condition that manifests in childhood, specifically the inattentive subtype of attention-deficit/hyperactivity disorder (ADHD). Because ADHD shares similar neurocognitive and symptomatological features with pediatric cancer, TBI, and SCD, stimulant medications may be indicated to treat associated deficits in each condition. However, relatively few studies have investigated the safety and effectiveness of stimulant medications in treating neurocognitive sequelae in children with cancer, TBI, or SCD. Thus, clinicians have received little guidance regarding a potentially useful treatment modality for ameliorating the neurocognitive deficits that can profoundly impact the educational, psychosocial, and vocational development of youth with these chronic health conditions. We provide a review of the literature and synthesize current developments in research regarding treatment with stimulant medication for children with cancer, TBI, and SCD, as well as discuss special considerations for each condition.

A Case for Mental and Physical Rest in Youth Sports Concussion: It's Never too Late

Over the past decade, there has been a considerable increase in research on, and media attention to, sports-related concussion. However, despite accurate diagnosis, effective treatment and management of sports-related concussion have remained a challenge. There are approximately 1.8 million traumatic brain injuries in the United States annually (Faul et al., 2010) and emergency department pediatric visits for suspected concussion have doubled in the past decade (Bakhos et al., 2010). However, health care providers and medical researchers have yet to offer an effective, reliable evidence-based treatment for concussive brain injury. The Zurich 2008 Consensus Statement on Concussion in Sport codified the prescription for cognitive and physical rest immediately following a concussion based on clinical acumen and common sense (McCrory et al., 2009). Currently, rest is the considered the best immediate treatment for concussion. Other supportive and anecdotal treatments are often applied throughout the post-concussive recovery process to address persistent symptoms. The need for empirical research to translate current guidelines for rest into evidence-based treatment protocols is essential. A recent study evaluated the efficacy of comprehensive rest and concluded that such rest may be helpful whether applied soon after a concussion or weeks to months later (Moser et al., 2012). Here, we present a case illustrating the effectiveness of rest in a youth athlete, commenced after experiencing 13 months of post-concussion symptoms. There appears to be value in applying a specific period of cognitive and physical rest following concussion, whether immediately or later in the recovery phase.

Subacute concussion-related symptoms and postconcussion syndrome in pediatrics

PURPOSE OF REVIEW

Millions of youth sustain concussion each year; although most fully recover following an isolated concussion, a significant minority develop prolonged symptoms and disability following concussion. This article reviews recent data regarding the epidemiology of postconcussion syndrome (PCS) and recommendations for the evaluation and management of postconcussive symptoms in pediatrics.

RECENT FINDINGS

PCS is a constellation of symptoms related to head injury including somatic symptoms, sleep dysregulation, cognitive deficits and emotional disturbance. Postconcussive symptoms affect 1.5-11% of concussed youth for more than 1 month after injury, depending on the population studied. Girls have a higher risk of postconcussive headache but it is not clear if cognitive recovery differs between the sexes. Advanced neuroimaging techniques demonstrate a correlation between postconcussive symptoms and functional neurological changes. However, pre-existing and psychosocial factors also affect risk for prolonged PCS. Current treatment strategies are based mainly on expert opinion and studies of related syndromes.

SUMMARY

Although a minority of concussed youth develop prolonged PCS, those who are affected can develop significant disability. Prolonged postconcussive symptoms are likely due to interactions between the biological injury, pre-existing risk factors and psychosocial issues. Further research is essential to improve outcomes for this vulnerable population.

Efficacy of immediate and delayed cognitive and physical rest for treatment of sports-related concussion

OBJECTIVES

To evaluate the efficacy of cognitive and physical rest for the treatment of concussion.

STUDY DESIGN

High school and collegiate athletes (N = 49) underwent post-concussion evaluations between April 2010 and September 2011 and were prescribed at least 1 week of cognitive and physical rest. Participants were assigned to groups on the basis of the time elapsed between sustaining a concussion and the onset of rest (1-7 days, 8-30 days, 31+ days). Main outcome measures included Concussion Symptom Scale ratings and scores on the 4 composite indices of the Immediate Post-Concussion Assessment and Cognitive Testing measure, both before and following rest. Mixed-factorial design ANOVA were used to compare changes on the dependent measures within and between groups.

RESULTS

Participants showed significantly improved performance on Immediate Post-Concussion Assessment and Cognitive Testing and decreased symptom reporting following prescribed cognitive and physical rest (P < .001), regardless of the time between concussion and onset of rest (P = .44).

CONCLUSION

These preliminary data suggest that a period of cognitive and physical rest may be a useful means of treating concussion-related symptoms, whether applied soon after a concussion or weeks to months later.

Evidence-based approaches to the management of cognitive and behavioral impairments following pediatric brain injury

Much is now known about the short- and long-term sequelae of pediatric acquired brain injury, with impairments found in general intellectual ability and in more specific domains, including attention, memory, executive functioning (e.g., planning and organization) and educational achievement (e.g., spelling and arithmetic). More recently, researchers have investigated behavioral, adaptive, social and mental health outcomes, and similarly, difficulties have been reported in these domains. While the availability of evidence-based treatments is currently limited, the need for the management of such sequelae has led to an emergence of research with a focus on the development and evaluation of management strategies and intervention programs in order to provide such treatment options.

Efficacy and safety of dopamine agonists in traumatic brain injury: a systematic review of randomized controlled trials

In the intensive care unit, dopamine agonists (DA) have been used in traumatic brain injury (TBI) patients to augment or accelerate cognitive recovery and rehabilitation. However, the efficacy and safety of DA in this population is not well established. We conducted a systematic review of randomized controlled trials (RCTs) examining the clinical efficacy and safety of DA in patients with TBI. We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials, comparing DA to either placebo, standard treatment, or another active comparator. There was no restriction for age, date, or language of publication. Sensitivity analyses were planned to evaluate the potential effect of timing of TBI, age, drugs, and year of publication on efficacy. Among the 790 citations identified, 20 RCTs evaluating methylphenidate, amantadine, and bromocriptine were eligible. Significant clinical heterogeneity was observed between and within studies, which precluded any pooling of data. Efficacy outcomes included mainly neuropsychological measures of cognitive functioning. A total of 76 different neuropsychological tests were used, but most of them (59%) only once. Only 5 studies systematically assessed safety. No trend could be drawn from the analysis of efficacy and safety. Important sources of bias in the studies were of major concern. Considering the absence of consensus regarding clinical outcome, the lack of safety assessment, and the high risk of bias in the included trials, more research is warranted before DA can be recommended in critically ill TBI patients.

Pediatric multiple sclerosis

In the past 5 years, there has been an exponential growth in the knowledge about multiple sclerosis (MS) in children and adolescents. Recent publications have shed light on its diagnosis, pathogenesis, clinical course, and treatment. However, there remain several key areas that require further exploration. This article summarizes the current state of knowledge on pediatric MS and discusses future avenues of investigation.

Medical therapies for concussion

Clinicians who manage sport-related concussions have excellent guidelines by which most injuries can be managed. Because sport-related concussions typically resolve within a short time frame, most can be managed with physical and cognitive rest alone. However, clinicians who specialize in the assessment and management of this diagnosis encounter patients with prolonged recovery courses, persistent symptoms, and significant deficits in cognitive functioning. These patients require more involved therapy, which may include additional education, academic accommodations, physical therapy, cognitive rehabilitation, and medication. This article reviews the main medical therapies for the management of concussive brain injury.

Amantadine treatment following traumatic brain injury in children

PRIMARY OBJECTIVE

The focus of this paper is to review the current literature on the use of amantadine in children who have sustained a head injury.

MAIN OUTCOMES AND RESULTS

A MEDLINE search was conducted and yielded five papers. They were composed of prospective, retrospective and case study designs. Dosage use and side effect profiles were consistent with expected norms. Efficacy was measures primarily by alertness and arousal and positive results were found for all studies on these dimensions. Behavioural and cognitive measures of outcome yielded mixed results.

CONCLUSIONS

The studies reviewed for this paper suggest that amantadine is clinically beneficial for children who have sustained head injuries. Double blind placebo controlled trials with larger sample sizes are needed to further substantiate these findings.

Traumatic brain injury in childhood: rehabilitation considerations

OBJECTIVE

The aims of this review were to: (i) briefly outline common sequelae following childhood traumatic brain injury (TBI); (ii) provide a summary of models and research in the area of intervention; (iii) discuss issues and obstacles in the evaluation of research in the area of intervention; (vi) discuss integrative and translational aspects of research in this area; (v) provide an example of intervention studies being conducted in the laboratory; and (vii) highlight the need for continued and collaborative work in the paediatric intervention field.

CONCLUSIONS

When reviewing the literature, it is clear that while challenging, the development and evaluation of intervention programs for children post traumatic brain injury, must be encourage and pursued. This in turn will lead to improved quality of life for these children and their families.

Acute brain injury and therapeutic hypothermia in the PICU: A rehabilitation perspective

Acquired brain injury from traumatic brain injury, cardiac arrest (CA), stroke, and central nervous system infection is a leading cause of morbidity and mortality in the pediatric population and reason for admission to inpatient rehabilitation. Therapeutic hypothermia is the only intervention shown to have efficacy from bench to bedside in improving neurological outcome after birth asphyxia and adult arrhythmia-induced CA, thought to be due to its multiple mechanisms of action. Research to determine if therapeutic hypothermia should be applied to other causes of brain injury and how to best apply it is underway in children and adults. Changes in clinical practice in the hospitalized brain-injured child may have effects on rehabilitation referral practices, goals and strategies of therapies offered, and may increase the degree of complex medical problems seen in children referred to inpatient rehabilitation.

Antiinfective agents affecting cognition: a review

The adverse effects of antimicrobial, antiviral and anthelmintic agents on cognitive function have attracted substantial research interest in the last three decades. There are sporadic individual reports of negative effects on cognition by penicillin, amoxycillin, cloxacillin, cephalothin, cephazolin, cefuroxime, ceftazidime, tobramycin, doxycycline, chloramphenicol, lomefloxacin, pefloxacin, isoniazid, amphotericin B, acyclovir, chloroquine, clioquinol, metronidazole, sulfasalazine among other antimicrobial agents. Antimicrobial and antiprotozoal agents reported to affect consciousness in particular are amoxycillin, cloxacillin, ticarcillin, cephalothin, cephazolin, ceftazidime, cefuroxime, tobramycin, lomefloxacin, pefloxacin, amphotericin B, acyclovir, chloroquine, clioquinol, and metronidazole. The relationship between some other antimicrobial, antiviral and anthelmintic agents and cognition is yet to be clearly established due to the existence of controversial reports. Few antimicrobial, antiviral or anthelmintic agents have been found to be devoid of any effect on memory. A few others may enhance cognitive performance. This review focuses on this issue, summarizing the published clinical and experimental studies relevant to this area of research and discussing its clinical implications. Suggested mechanisms responsible for the adverse effects of different antimicrobial, antiviral, and anthelmintic agents on cognitive function are reported. Future recommendations point to immense research opportunities to investigate the cognitive profile of newly discovered antimicrobial agents.

Pharmacological management of neurobehavioural sequelae of traumatic brain injury: a survey of current physiatric practice

OBJECTIVE

To describe pharmacological preference for the treatment of neurobehavioural sequela of traumatic brain injury (TBI).

DESIGN

Survey.

PARTICIPANTS

TBI physiatrists were divided into specialists (completed a TBI fellowship or commit >70% of clinical practice time to TBI) and non-specialists.

OUTCOME MEASURES

Participants were asked to list the drugs most frequently prescribed for each of 15 neurobehavioural symptoms commonly encountered during TBI rehabilitation and enumerate neurobehavioural symptom for which they prescribed each listed drug or drug class.

RESULTS

There was no clear consensus on drug of choice for each target symptom. There were differences in drug choice patterns between specialists and non-specialists, especially for agitation.

CONCLUSION

There is limited uniformity in drug selection for various TBI neurobehavioural sequela. Potential explanations include the availability of various medications with similar clinical effect, the variability of clinical presentation and severity of neurobehavioural symptoms and the lack of clinical practice guidelines.

A review of pharmacological treatments used in experimental models of traumatic brain injury

PRIMARY OBJECTIVE

We provide a review of recent chronic and delayed rehabilitative pharmacological treatments examined in experimental models of traumatic brain injury. There is a specific emphasis on studies aiming to enhance cognitive recovery.

MAIN OUTCOMES AND RESULTS

Decreased neuronal activity is believed to contribute to persistent cognitive disabilities. Neurotransmitter based rehabilitative treatments that increase neuronal activity may assist in the recovery of cognitive function. However, timing and dosage of drug treatment are influential in cognitive enhancement. Drug treatments that affect single and multiple neurotransmitter systems have the ability to significantly influence recovery of function following brain injury.

CONCLUSIONS

Understanding the relationship between neural disturbances and functional deficits following brain injury is challenging. Cognitive impairment may be the result of a single event or multiple events that occur after the initial insult. Increasing neuronal activity during the chronic phase of injury seems to be an effective treatment strategy for facilitating cognitive recovery. Pharmacological agents do not necessarily display the same effects in an injured brain as in a non-injured brain. Thus, further research is needed to establish the effectiveness of rehabilitative drug treatments.

Pharmacological enhancement of cognitive and behavioral deficits after traumatic brain injury

PURPOSE OF REVIEW

To provide the clinician with a reasonable overview of the modern pharmacological alternatives to treat the cognitive and behavioral sequels of traumatic brain injury.

RECENT FINDINGS

Original research in this area is sparse and more than half of the articles published on the subject recently have been reviews. Of the three randomized controlled trials, one studied methylphenidate (n = 18), one methylphenidate and sertraline (n = 30) and one amantadine (n = 27). All these studies reported beneficial effects on various cognitive measures, but because of the study protocols, the evidence provided may be questioned. The various reviews, uncontrolled studies and case reports suggest that at least psychostimulants, cholinergic agents, dopaminergic agents and antidepressants may be beneficial in treating the cognitive and behavioral symptoms of traumatic brain injury.

SUMMARY

The clinician trying to ameliorate the cognitive and behavioral symptoms of traumatic brain injury has to make decisions about pharmacotherapy that are still based mainly on clinical experience. Large randomized controlled trials giving high-quality evidence are so far missing. This review discusses the problems facing both the clinician and the scientist treating the cognitive and behavioral sequels of traumatic brain injury. A symptom-based approach is suggested for current practice.