Amantadine treatment following traumatic brain injury in children

Revisiting Excitotoxicity in Traumatic Brain Injury: From Bench to Bedside

Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality. Consequences vary from mild cognitive impairment to death and, no matter the severity of subsequent sequelae, it represents a high burden for affected patients and for the health care system. Brain trauma can cause neuronal death through mechanical forces that disrupt cell architecture, and other secondary consequences through mechanisms such as inflammation, oxidative stress, programmed cell death, and, most importantly, excitotoxicity. This review aims to provide a comprehensive understanding of the many classical and novel pathways implicated in tissue damage following TBI. We summarize the preclinical evidence of potential therapeutic interventions and describe the available clinical evaluation of novel drug targets such as vitamin B12 and ifenprodil, among others.

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.

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.

A selective review of glutamate pharmacological therapy in obsessive-compulsive and related disorders

Glutamate, an excitatory central nervous system neurotransmitter, is emerging as a potential alternative pharmacological treatment when compared to gamma-aminobutyric acid (GABA)-, dopamine-, and serotonin-modulating treatments for neuropsychiatric conditions. The pathophysiology, animal models, and clinical trials of glutamate modulation are explored in disorders with underlying inhibitory deficits (cognitive, motor, behavioral) including obsessive–compulsive disorder, attention deficit hyperactivity disorder, Tourette syndrome, trichotillomania, excoriation disorder, and nail biting. Obsessive–compulsive disorder, attention deficit hyperactivity disorder, and grooming disorders (trichotillomania and excoriation disorder) have emerging positive data, although only scarce controlled trials are available. The evidence is less supportive for the use of glutamate modulators in Tourette syndrome. Glutamate-modulating agents show promise in the treatment of disorders of inhibition.

Amantadine ameliorates dopamine-releasing deficits and behavioral deficits in rats after fluid percussion injury

Aims

To investigate the role of dopamine in cognitive and motor learning skill deficits after a traumatic brain injury (TBI), we investigated dopamine release and behavioral changes at a series of time points after fluid percussion injury, and explored the potential of amantadine hydrochloride as a chronic treatment to provide behavioral recovery.

Materials and Methods

In this study, we sequentially investigated dopamine release at the striatum and behavioral changes at 1, 2, 4, 6, and 8 weeks after fluid percussion injury. Rats subjected to 6-Pa cerebral cortical fluid percussion injury were treated by using subcutaneous infusion pumps filled with either saline (sham group) or amantadine hydrochloride, with a releasing rate of 3.6mg/kg/hour for 8 weeks. The dopamine-releasing conditions and metabolism were analyzed sequentially by fast scan cyclic voltammetry (FSCV) and high-pressure liquid chromatography (HPLC). Novel object recognition (NOR) and fixed-speed rotarod (FSRR) behavioral tests were used to determine treatment effects on cognitive and motor deficits after injury.

Results

Sequential dopamine-release deficits were revealed in 6-Pa-fluid-percussion cerebral cortical injured animals. The reuptake rate (tau value) of dopamine in injured animals was prolonged, but the tau value became close to the value for the control group after amantadine therapy. Cognitive and motor learning impairments were shown evidenced by the NOR and FSRR behavioral tests after injury. Chronic amantadine therapy reversed dopamine-release deficits, and behavioral impairment after fluid percussion injuries were ameliorated in the rats treated by using amantadine-pumping infusion.

Conclusion

Chronic treatment with amantadine hydrochloride can ameliorate dopamine-release deficits as well as cognitive and motor deficits caused by cerebral fluid-percussion injury.

Management strategies and medication use for treating paediatric patients with concussions

AIM

To assess management strategies for paediatric patients suffering from concussions.

METHODS

A 17-item questionnaire was distributed to 1305 section members of the American Academy of Pediatrics Sections on Adolescent Health, Sports Medicine and Fitness, Community Pediatrics and School Health. The use of medications, neuropsychological testing, neuroimaging and published guidelines in concussion management was queried.

RESULTS

Two hundred and twenty respondents (17%) completed the questionnaire, of which 64% had been an attending for greater than 10 years. A majority of respondents (92%) managed patients with concussions, with 26% treating more than 24 patients per year. Most paediatricians (84%) reported using a published guideline. The majority of respondents (89%) manage the symptoms of concussed patients with medications, most commonly acetaminophen (62%) or nonsteroidal anti-inflammatory medications (54%). The use of prescriptions medications such as tricyclic antidepressants (23%), amantadine (10%) and methylphenidate (8%) was also commonly reported. Paediatricians treating >16 patients per year with concussion were more likely to prescribe tricyclic antidepressants, stimulants and agents used for sleep disturbance.

CONCLUSION

Paediatricians nationwide routinely use medications when managing patients with concussions. The pharmacological agents used differ according to number of patients treated per year. In addition, most paediatricians use published guidelines in concussion management.

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.

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.

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.

Practitioner review: beyond shaken baby syndrome: what influences the outcomes for infants following traumatic brain injury?

BACKGROUND

Traumatic brain injury (TBI) in infancy is relatively common, and is likely to lead to poorer outcomes than injuries sustained later in childhood. While the headlines have been grabbed by infant TBI caused by abuse, often known as shaken baby syndrome, the evidence base for how to support children following TBI in infancy is thin. These children are likely to benefit from ongoing assessment and intervention, because brain injuries sustained in the first year of life can influence development in different ways over many years.

METHODS

A literature search was conducted and drawn together into a review aimed at informing practitioners working with children who had a brain injury in infancy. As there are so few evidence-based studies specifically looking at children who have sustained a TBI in infancy, ideas are drawn from a range of studies, including different age ranges and difficulties other than traumatic brain injury.

RESULTS

This paper outlines the issues around measuring outcomes for children following TBI in the first year of life. An explanation of outcomes which are more likely for children following TBI in infancy is provided, in the areas of mortality; convulsions; endocrine problems; sensory and motor skills; cognitive processing; language; academic attainments; executive functions; and psychosocial difficulties. The key factors influencing these outcomes are then set out, including severity of injury; pre-morbid situation; genetics; family factors and interventions.

CONCLUSIONS

Practitioners need to take a long-term, developmental view when assessing, understanding and supporting children who have sustained a TBI in their first year of life. The literature suggests some interventions which may be useful in prevention, acute care and longer-term rehabilitation, and further research is needed to assess their effectiveness.

Pediatric rehabilitation: 1. Common medical conditions in children with disabilities

OBJECTIVE

This self-directed learning module focuses on the physiatric management of the common morbidities associated with pediatric traumatic brain injury and cerebral palsy. It is part of the study guide on pediatric rehabilitation in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation and pediatric medicine. The goal of this article is to enhance the learner's knowledge regarding current physiatric management of complications related with pediatric traumatic brain injury and cerebral palsy.