Phenytoin increases the severity of cortical hemiplegia in rats

Stroke Rehabilitation and Motor Recovery

OBJECTIVE

Up to 50% of the nearly 800,000 patients who experience a new or recurrent stroke each year in the United States fail to achieve full independence afterward. More effective approaches to enhance motor recovery following stroke are needed. This article reviews the rehabilitative principles and strategies that can be used to maximize post-stroke recovery.

LATEST DEVELOPMENTS

Evidence dictates that mobilization should not begin prior to 24 hours following stroke, but detailed guidelines beyond this are lacking. Specific classes of potentially detrimental medications should be avoided in the early days poststroke. Patients with stroke who are unable to return home should be referred for evaluation to an inpatient rehabilitation facility. Research suggests that a substantial increase in both the dose and intensity of upper and lower extremity exercise is beneficial. A clinical trial supports vagus nerve stimulation as an adjunct to occupational therapy for motor recovery in the upper extremity. The data remain somewhat mixed as to whether robotics, transcranial magnetic stimulation, functional electrical stimulation, and transcranial direct current stimulation are better than dose-matched traditional exercise. No current drug therapy has been proven to augment exercise poststroke to enhance motor recovery.

ESSENTIAL POINTS

Neurologists will collaborate with rehabilitation professionals for several months following a patient's stroke. Many questions still remain about the ideal exercise regimen to maximize motor recovery in patients poststroke. The next several years will likely bring a host of new research studies exploring the latest strategies to enhance motor recovery using poststroke exercise.

Neuroprotective effects of Lasmiditan and Sumatriptan in an experimental model of post-stroke seizure in mice: Higher effects with concurrent opioid receptors or KATP channels inhibitors

BACKGROUND

Early post-stroke seizure frequently occurs in stroke survivors within the first few days and is associated with poor functional outcomes. Therefore, efficient treatments of such complications with less adverse effects are pivotal. In this study, we investigated the possible beneficial effects of lasmiditan and sumatriptan against post-stroke seizures in mice and explored underlying mechanisms in their effects.

METHODS

Stroke was induced by double ligation of the right common carotid artery in mice. Immediately after the ligation, lasmiditan (0.1 mg/kg, intraperitoneally [i.p.]) or sumatriptan (0.03 mg/kg, i.p.) were administered. Twenty-four hours after the stroke induction, seizure susceptibility was evaluated using the pentylenetetrazole (PTZ)-induced clonic seizure model. In separate experiments, naltrexone (a non-specific opioid receptor antagonist) and glibenclamide (a K_ATP channel blocker) were administered 15 min before lasmiditan or sumatriptan injection. To evaluate the underlying signaling pathways, ELISA analysis of inflammatory cytokines (TNF-α and IL-1β) and western blot analysis of anti- and pro-apoptotic markers (Bcl-2 and Bax) were performed on mice isolated brain tissues.

RESULTS

Lasmiditan (0.1 mg/kg, i.p.) and sumatriptan (0.03 mg/kg, i.p.) remarkably decreased seizure susceptibility in stroke animals by reducing inflammatory cytokines and neuronal apoptosis. Concurrent administration of naltrexone (10 mg/kg, i.p.) or glibenclamide (0.3 mg/kg, i.p.) with lasmiditan or sumatriptan resulted in a higher neuroprotection against clonic seizures and efficiently reduced the inflammatory and apoptotic markers.

CONCLUSION

Lasmiditan and sumatriptan significantly increased post-stroke seizure thresholds in mice by suppressing inflammatory cytokines and neuronal apoptosis. Lasmiditan and sumatriptan seem to exert higher effects on seizure threshold with concurrent administration of the opioid receptors or K_ATP channels modulators.

Anti-Epileptic Medication Exposure Influences Functional Status in New Zealand Stroke Patients: A Retrospective Population-Level Study

Background

Patients who develop seizures after stroke have disproportionately poorer outcomes and increased mortality.

Objective

Our objective was to investigate whether exposure to anti-epileptic medications influenced long-term functional status after stroke.

Methods

We used linked health administrative data from a cohort of adult stroke patients in New Zealand. Demographics and prescription information were obtained from the National Minimum Dataset and Pharmaceutical Collection, respectively. Activities of daily living (ADL) scores for the same patients were obtained using the International Resident Assessment Instrument. Beta regression was used to investigate the relationship between anti-epileptic drug (AED) exposure and functional status.

Results

The study included 3606 patients with a single ischaemic stroke between 2012 and 2017. In total, 15% were dispensed an AED in the 3 months before or after stroke. The adjusted odds ratio (OR) for AED exposure was 1.29 (95% confidence interval [CI] 1.15–1.45). Overall AED exposure, categorical body mass index (BMI), ethnicity, length of hospital stay, and exposure to paracetamol, opioids, anti-psychotics, and anti-nausea medications were significantly associated with changes in the mean ADL score percentages. Considering the exposure timeframe, the ORs for AED exposure only after stroke and for exposure both before and after stroke were 1.52 (95% CI 1.31–1.78) and 1.09 (95% CI 0.93–1.27), respectively.

Conclusion

Stroke patients with AED exposure had greater odds of a higher ADL score, indicating a poorer long-term functional status than those unexposed to AEDs. The timeframe of exposure impacted on functional status, with patients exposed only after stroke having increased odds of higher ADL scores than those exposed both before and after stroke.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-021-00280-5.

Poststroke epilepsy: current perspectives on diagnosis and treatment

Seizures and epilepsy are quite a common outcome of arterial ischemic stroke (AIS) both in pediatric and adult patients, with distinctly higher occurrence in children. These poststroke consequences affect patients' lives, often causing disability. Poststroke seizure (PSS) may also increase mortality in patients with AIS. Early PSS (EPSS) occurring up to 7 days after AIS, late PSS (LPSS) occurring up to 2 years after the onset of AIS, as well as poststroke epilepsy (PSE) can be distinguished. However, the exact definition and cutoff point for PSE should be determined. A wide range of risk factors for seizures and epilepsy after AIS are still being detected and analyzed. More accurate knowledge on risk factors for PSS and PSE as well as possible prediction of epileptic seizures after the onset of AIS may have an impact on improving the prevention and treatment of PSE. The aim of the present review was to discuss current perspectives on diagnosis and treatment of PSS and PSE, both in adult and paediatric patients.

Seizures in the acute stroke setting

Stroke is one of the leading causes of long-term disability. One in six people in the world will suffer a stroke in their lifetime, with the annual incidence about 117 per 100,000 person-years in developing countries. It has also been shown to be the cause of 10-15% of epilepsies, more prevalent in patients above 60 years of age. The incidence of early seizures in acute stroke ranges 3-33%, with 50-78% of the seizures occurring within the first 24 hours. Occurrence of seizures within 24 hours of stroke is associated with higher 30-day mortality, which may be a reflection of severe neuronal damage. Alteration in intracellular ion concentrations and hyper-excitability are thought to be etiologies for early seizures in acute stroke, and the increased stress on already vulnerable tissues may result in worsening of stroke symptoms. Early detection of seizures and subsequent effective treatment can prevent additional metabolic burden and damage to the blood-brain barrier, which may improve recovery and overall outcome. Clinical seizures can be recognized readily at bedside and lead to prompt medical intervention. In contrast, electrographic seizures with subtle or no clinical sign and non-convulsive status epilepticus (NCSE) may escape clinical observation and be left untreated. With the use of continuous electroencephalogram monitoring (cEEG), patients with electrographic seizures can be better identified and medically treated more quickly. In addition to electrographic seizures, the presence of isolated and periodic epileptiform patterns on electroencephalogram (EEG) suggests the need for medical treatment since up to 75% of these patients have been found to develop early post-stroke seizures. Newer anti-epileptic medications with intravenous formulation, together with traditional regimen and barbiturate, have shown promise in controlling early post-stroke seizures and possibly improving outcome.

Antiepileptic drugs for the primary and secondary prevention of seizures after subarachnoid haemorrhage

BACKGROUND

Subarachnoid haemorrhage may result in seizures both acutely and in the longer term. The use of antiepileptic drugs (AEDs) in the primary and secondary prevention of seizures after subarachnoid haemorrhage is uncertain, and there is currently no consensus on treatment.

OBJECTIVES

To assess the effects of AEDs for the primary and secondary prevention of seizures after subarachnoid haemorrhage.

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 1) in The Cochrane Library, and MEDLINE (1946 to 12th March 2013). We checked the reference lists of articles retrieved from these searches.

SELECTION CRITERIA

We considered all randomised and quasi-randomised controlled trials in which patients were assigned to a treatment (one or more AEDs) or placebo.

DATA COLLECTION AND ANALYSIS

Two review authors (RM and JK) independently screened and assessed the methodological quality of the studies. If studies were included, one author extracted the data and the other checked it.

MAIN RESULTS

No relevant studies were found.

AUTHORS' CONCLUSIONS

There was no evidence to support or refute the use of antiepileptic drugs for the primary or secondary prevention of seizures related to subarachnoid haemorrhage. Well-designed randomised controlled trials are urgently needed to guide clinical practice.

A prospective test of the late effects of potentially antineuroplastic drugs in a stroke rehabilitation study

BACKGROUND

Extensive data, primarily from animal studies, suggest that several classes of drugs may have antineuroplastic effects that could impede recovery from brain injury or reduce the efficacy of rehabilitation.

AIMS

The Locomotor Experience Applied Post-Stroke trial, a randomized controlled study of 408 subjects that tested the relative efficacy of two rehabilitation techniques on functional walking level at one-year poststroke, provided us the opportunity to prospectively assess the potential antineuroplastic effects of several classes of drug.

METHODS

Subjects were randomized to receive one of the two rehabilitation therapies at two-months poststroke. Drugs taken were recorded at time of randomization. Outcome was assessed at one-year poststroke. Regression models were used to determine the amount of variance in success in improving functional walking level, gains in walking speed, and declines in lower extremity, upper extremity, and cognitive impairment accounted for by α1 noradrenergic blockers + α2 noradrenergic agonists, benzodiazepines, voltage-sensitive sodium channel anticonvulsants, and α2δ voltage-sensitive calcium channel blockers.

RESULTS

The maximum variance accounted for by any drug class was 1.66%. Drug effects were not statistically significant when using even our most lenient standard for correction for multiple comparisons.

CONCLUSIONS

Drugs in the classes we were able to assess do not appear to exert a clinically important effect on outcome over the period between two- and 12 months poststroke. However, the potential antineuroplastic effects of certain drugs remain an incompletely settled scientific question.

Dilantin therapy in an experimental model of traumatic brain injury: effects of limited versus daily treatment on neurological and behavioral recovery

The mechanisms by which Dilantin confers anticonvulsant benefits may also be neuroprotective by attenuating the acute excitatory insult in cortical and subcortical structures when the drug is given in the acute phase after traumatic brain injury (TBI). However, when Dilantin is used for prolonged periods, we hypothesized that it may impede recovery, synaptic plasticity may be impaired, and neuroprotective benefits may be lost. As such, we assessed the effect of daily chronic administration (75 mg/kg day 0 followed by 50 mg/kg daily i.p.) and acute administration (75 mg/kg day 0 followed by 50 mg/kg i.p. day 1) of Dilantin in young adult male rats on motor performance, y-maze exploration, Morris Water Maze (MWM), hippocampal (HC) cell survival, contusion size, and regional expression of neuroplasticity markers after controlled cortical impact (CCI) injury. Chronic daily Dilantin administration resulted in beam walking impairments on day 6, whereas acute Dilantin administration resulted in beam walking impairments on days 3 and 4. Chronic Dilantin administration also resulted in worse MWM performance, more HC cell loss and no increases in neuroplasticity markers compared to rats with CCI receiving chronic vehicle. Conversely, rats receiving acute Dilantin administration exhibited more novel arm exploration in the y-maze, greater HC cell sparing, and greater growth-associated protein 43 (GAP-43) expression in the HC ipsilateral to the CCI, compared to injured rats receiving vehicle. MWM was not influenced by acute Dilantin administration. These results suggest that there are beneficial effects of limited acute Dilantin therapy after TBI, and that extended daily Dilantin therapy has deleterious effects on neural recovery. These findings support clinical guidelines for limited use of Dilantin in seizure prophylaxis after TBI.

Ischaemic stroke in adults and epilepsy

Stroke is an important cause of symptomatic epilepsy especially in the elderly. Seizures in the setting of stroke will furthermore worsen the prognosis of stroke. Studies show that the frequency of seizures in stroke ranges between 2.3% and 14%. Typically early seizures are defined as those that occur within 14 days of the stroke, and later seizures those that occur after this period. A number of risk factors have been identified like cortical involvement, size of the infarct and stroke severity. Status epilepticus can be a presenting symptom of acute stroke and can lead to increased mortality. Early seizures are risks for recurrent seizures though not for the development of epilepsy but late seizures do carry a higher risk. There are no clear cut guidelines for the treatment of seizures in stroke and hence treatment needs to be initiated in the context of the patient. The presence of co morbid conditions and the use of other drugs also complicate antiepileptic therapy, and the risk of drug interactions is a particular hazard in elderly patients on multiple co medication. Although hemorrhagic and ischaemic stroke can both result in epilepsy, this review focuses primarily the association of epilepsy and ischaemic stroke.

[Seizures and epilepsies after stroke]

Epilepsies after stroke represent 20% of all adult-onset epilepsies and exhibit special characteristics with respect to diagnosis, treatment, and prognosis. Patients are frequently amnestic for their seizures the signs of which can be very subtle. Postictal pareses and confusional states can last for days, which further complicate diagnosis. Single seizures after stroke were reported in 2% to 10% of cases, and community-based studies found epilepsies in 3% to 4% of stroke patients. Analyses of subgroups identified epilepsy risks of 3% after ischemic infarction, 6% to 10% after intracerebral hemorrhage, and 9% after subarachnoid hemorrhage. Status epilepticus developed in less than 1% of stroke patients. Besides etiology, further risk factors for epilepsy comprise: remote seizures (latency >2 weeks, risk of recurrence >50%) more than early seizures (latency <2 weeks, risk of recurrence <50%), extent of stroke, cortical involvement, and degree of neurological deficit. The first appearance of seizures in patients older than 60 years represents a risk factor for future stroke with a hazard ratio of 2.89.There is currently no sufficient evidence for starting AED treatment before seizures occur. The benefit is still unclear of starting AED after a single early post-stroke seizure. Most authors recommend AED treatment after the second seizure but also after a first remote seizure because of the high risk of seizure recurrence in these situations. Possible pharmacokinetic interactions should be considered when choosing AED. Especially the first-generation AED carry the potential to interact with comedication, which is usually seen in stroke patients receiving substances such warfarin and salicylates. Only very few studies investigate specific AED exclusively in stroke patients. Lamotrigine and gabapentin have been successfully tested in these patients.

Predictors of seizure onset after intracerebral hemorrhage and the role of long-term antiepileptic therapy

OBJECTIVE

Seizures are a common complication after hemorrhagic stroke that may slow recovery and decrease quality of life. Recent evidence suggests that early- and late-onset seizures have distinct etiologies, rendering the role of prophylactic long-term antiepileptic drugs controversial. We investigated predictors of early- and late-onset seizures after evacuation of intracerebral hemorrhage (ICH) in an attempt to guide antiepileptic drug management in this patient population.

METHODS

We performed a retrospective analysis of 110 patients admitted to Columbia University Medical Center between 1999 and 2007 for ICH and subsequent clot evacuation. Patients were included if they had a head computed tomography indicating ICH, an operative note confirming surgical evacuation, and sufficient medical records to determine seizure status. Demographic, clinical, and radiographic findings were recorded. Univariate and multivariate logistic regression analyses were used to determine factors associated with early- and late-onset electrographic and clinical seizures.

RESULTS

Seizures occurred in 41.8% of patients, 29.6% of which had clinical manifestations and 16.3% of which were recorded on continuous electroencephalogram (EEG). After controlling for demographic factors, multivariate analysis identified 3 factors that were predictive of early-onset seizures (volume of hemorrhage, presence of subarachnoid hemorrhage, and subdural hemorrhage) and 2 factors that were predictive of late onset seizures (subdural hemorrhage and increased admission international normalized ratio (INR)).

CONCLUSIONS

The presence of subdural hematoma and increased INR is predictive of late-onset seizures in patients undergoing clot evacuation after ICH. The use of long-term antiepileptic therapy should be further studied in patients with these radiographic and clinical characteristics.

Pharmacological modulation of cortical plasticity following kainic acid lesion in rat barrel cortex

OBJECT

The brain shows remarkable capacity for plasticity in response to injury. To maximize the benefits of current neurological treatment and to minimize the impact of injury, the authors examined the ability of commonly administered drugs, dextroamphetamine (D-amphetamine) and phenytoin, to positively or negatively affect the functional recovery of the cerebral cortex following excitotoxic injury.

METHODS

Previous work from the same laboratory has demonstrated reorganization of whisker functional responses (WFRs) in the rat barrel cortex after excitotoxic lesions were created with kainic acid (KA). In the present study, WFRs were mapped using intrinsic optical signal imaging before and 9 days after creation of the KA lesions. During the post-lesion survival period, animals were either treated with intraperitoneal D-amphetamine, phenytoin, or saline or received no treatment. Following the survival period, WFRs were again measured and compared with prelesion data.

RESULTS

The findings suggest that KA lesions cause increases in WFR areas when compared with controls. Treatment with D-amphetamine further increased the WFR area (p < 0.05) while phenytoin-treated rats showed decreases in WFR areas. There was also a statistically significant difference (p < 0.05) between the D-amphetamine and phenytoin groups.

CONCLUSIONS

These results show that 2 commonly used drugs, D-amphetamine and phenytoin, have opposite effects in the functional recovery/plasticity of injured cerebral cortex. The authors' findings emphasize the complex nature of the cortical response to injury and have implications for understanding the biology of the effects of different medications on eventual functional brain recovery.

[Seizure and epilepsy after stroke]

Seizures and status epilepticus may be an early (<7-14 days) or late (>14 days) complication of acute stroke. Epilepsy, defined by at least two unprovoked epileptic seizures, may also be a late complication. Several risk factors have been identified for early and late seizures. Early seizures are more frequent in severe and disabling ischemic strokes, hemorrhagic strokes and those with cortical involvement. The risk of epilepsy is higher for patients with early seizures or cortical infarctions and in severely handicapped patients. Overall, approximately 4% of patient with an acute stroke will have at least one seizure in the early or late period, and half of them will develop epilepsy. Neither early nor late seizures appear to have a significant impact on mortality, although status epilepticus remains a life-threatening and often fatal event. The decision whether to start antiepileptic treatment after a first seizure or wait for a recurrence remains controversial. Risk of drug interactions and adverse effects in stroke patients must be kept in mind when prescribing antiepileptic drugs.

Pharmacological management for agitation and aggression in people with acquired brain injury

BACKGROUND

Of the many psychiatric symptoms that may result from brain injury, agitation and/or aggression are often the most troublesome. It is therefore important to evaluate the efficacy of psychotropic medication used in its management.

OBJECTIVES

To evaluate the effects of drugs for agitation and/or aggression following acquired brain injury (ABI).

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and other electronic databases. We also searched the reference lists of included studies and recent reviews. In addition we handsearched the journals Brain Injury and the Journal of Head Trauma Rehabilitation. There were no language restrictions. The searches were last updated in June 2006.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that evaluated the efficacy of drugs acting on the central nervous system for agitation and/or aggression, secondary to ABI, in participants over 10 years of age.

DATA COLLECTION AND ANALYSIS

We independently extracted data and assessed trial quality. Studies of patients within six months after brain injury and/or in a confusional state, were distinguished from those of patients more than six months post-injury, or who were not confused.

MAIN RESULTS

Six RCTs were identified and included in this review. Four of theses evaluated the beta-blockers, propranolol and pindolol, one evaluated the central nervous system stimulant, methylphenidate and one evaluated amantadine, a drug normally used in parkinsonism and related disorders. The best evidence of effectiveness in the management of agitation and/or aggression following ABI was for beta-blockers. Two RCTs found propranolol to be effective (one study early and one late after injury). However, these studies used relatively small numbers, have not been replicated, used large doses, and did not use a global outcome measure or long-term follow-up. Comparing early agitation to late aggression, there was no evidence for a differential drug response. Firm evidence that carbamazepine or valproate is effective in the management of agitation and/or aggression following ABI is lacking.

AUTHORS' CONCLUSIONS

Numerous drugs have been tried in the management of aggression in ABI but without firm evidence of their efficacy. It is therefore important to choose drugs with few side effects and to monitor their effect. Beta-blockers have the best evidence for efficacy and deserve more attention. The lack of evidence highlights the need for better evaluations of drugs for this important problem.

Post-Traumatic Neural Depression and Neurobehavioral Recovery after Brain Injury

There are an estimated 2 million traumatic brain injuries (TBIs) each year in the United States, making the yearly incidence eight times greater than that of breast cancer and 34 times greater than HIV/AIDS. Still, it remains a "silent epidemic" because TBI results in persistent neurobehavioral impairment, without necessarily imparting a physical scar. The present review is a comparative analysis of TBI research, both basic and applied, outlining the evidence that at least one component of the brain's innate response to insult (e.g., post-traumatic neural depression) is sufficiently well understood to be the target of additional clinical studies and therapeutic strategy development.

Predictors of outcome in prolonged posttraumatic disorders of consciousness and assessment of medication effects: A multicenter study

OBJECTIVES

To develop predictive models of recovery from the vegetative state (VS) and minimally conscious state (MCS) after traumatic brain injury (TBI) and to gather preliminary evidence on the impact of various psychotropic medications on the recovery process to support future randomized controlled trials. Design Longitudinal observational cohort design, in which demographic information, injury and acute care history, neuroimaging data, and an initial Disability Rating Scale (DRS) score were collected at the time of study enrollment. Weekly follow-up data, consisting of DRS score, current psychoactive medications, and medical complications, were gathered until discharge from inpatient rehabilitation.

SETTING

Seven acute inpatient rehabilitation facilities in the United States and Europe with specialized programs for treating patients in the VS and MCS.

PARTICIPANTS

People with TBI (N=124) who were in the VS or MCS 4 to 16 weeks after injury.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

DRS score at 16 weeks after injury and time until commands were first followed (among those participants demonstrating no command following at study enrollment). Results DRS score at enrollment, time between injury and enrollment, and rate of DRS change during the first 2 weeks of poststudy observation were all highly predictive of both outcomes. No variables related to injury characteristics or lesions on neuroimaging were significant predictors. Of the psychoactive medications, amantadine hydrochloride was associated with greater recovery and dantrolene sodium was associated with less recovery, in terms of the DRS score at 16 weeks but not the time until commands were followed. More detailed analysis of the timing of functional improvement, with respect to the initiation of amantadine provided suggestive, but not definitive, evidence of the drug's causal role.

CONCLUSIONS

These findings show the feasibility of improving outcome prediction from the VS and MCS using readily available clinical variables and provide suggestive evidence for the effects of amantadine and dantrolene, but these results require confirmation through randomized controlled trials.

Seizures and Epilepsy After Ischemic Stroke

Background— Although a long-recognized clinical phenomenon, there remain many questions regarding the epidemiology of seizures and epilepsy after ischemic stroke, their effect on outcome, and their treatment.

Summary of Review— Interpretation of the various studies that have been conducted of postischemic stroke seizures and epilepsy are complicated by their heterogeneous designs, inconsistent uses of terminology, small sample sizes, different periods of follow-up, and ambiguities in seizure identification and classification. Estimates of the rate of early postischemic stroke seizures range from 2% to 33%. The rates of late seizures vary from 3% to 67%. The rate of postischemic stroke epilepsy is ≈2% to 4% and is higher in those who have a late seizure. Data reflecting seizure subtypes are limited. Aside from cortical location and, possibly, stroke severity, no other risk factors for postischemic stroke seizures have been consistently demonstrated. Results regarding the impact of postischemic stroke seizures on outcome are inconsistent.

Conclusions— Much additional work is needed to better understand the epidemiology and social impact of postischemic stroke seizures and epilepsy, their prevention, and optimal management.

A randomized, double-blinded, placebo-controlled trial of phenytoin for the prevention of early posttraumatic seizures in children with moderate to severe blunt head injury

STUDY OBJECTIVE

We determine the efficacy of prophylactic phenytoin in preventing early posttraumatic seizures in children with moderate to severe blunt head injury.

METHODS

Children younger than 16 years and experiencing moderate to severe blunt head injury were randomized to receive phenytoin or placebo within 60 minutes of presentation at 3 pediatric trauma centers. The primary endpoint was posttraumatic seizures within 48 hours; secondary endpoints were survival and neurologic outcome 30 days after injury. A Bayesian decision-theoretic clinical trial design was used to determine the probability of remaining posttraumatic seizure free for each treatment group.

RESULTS

One hundred two patients were enrolled, with a median age of 6.1 years. Sixty-eight percent were boys. The 2 treatment groups were well matched. During the 48-hour observation period, 3 (7%) of 46 patients given phenytoin and 3 (5%) of 56 patients given placebo experienced a posttraumatic seizure. There were no significant differences between the treatment groups in survival or neurologic outcome after 30 days. According to these results, the probability that phenytoin has the originally hypothesized effect of reducing the rate of early posttraumatic seizures by 12.5% is 0.0053. The probability that phenytoin has any prophylactic efficacy is 0.383. The median effect size in this trial was -0.015 (seizure rate increased by 1.5% in the phenytoin group), 95% probability interval -0.127 to 0.091 (12.7% higher rate of posttraumatic seizures to a 9.1% lower rate of posttraumatic seizures with phenytoin).

CONCLUSION

The rate of early posttraumatic seizures in children may be much lower than previously reported. Phenytoin did not substantially reduce that rate.

Neuropharmacology of TBI-induced plasticity

PRIMARY OBJECTIVE

The purpose of this report is to review both fundamental studies in laboratory animals and preliminary clinical data suggesting that certain drugs may affect behavioural recovery after brain injury.

MAIN OUTCOMES AND RESULTS

Laboratory studies show that systemically-administered drugs that affect specific central neurotransmitters including norepinephrine and GABA influence affect recovery in a predictable manner. Although some drugs such as d-amphetamine have the potential to enhance recovery, others such as neuroleptics and other central dopamine receptor antagonists, benzodiazepines and the anti-convulsants phenytoin and phenobarbital may be detrimental. In one study, 72% of patients with traumatic brain injury received one or a combination of the drugs that may impair recovery based on both animal experiments and studies in recovering stroke patients.

CONCLUSIONS

Until the true impact of these classes of drugs are better understood, care should be exercised in the use of medications that may interfere with the recovery process in patients with traumatic brain injury. Additional research needs to be completed before the clinical efficacy of drugs that may enhance recovery can be established.

Amphetamines and related drugs in motor recovery after stroke

Studies in laboratory animals indicate that the rate and extent of functional recovery after focal brain injury can be modulated by drugs affecting specific central neurotransmitters. Preliminary clinical studies suggest that similar drug effects may occur in humans recovering from stroke. Combined with principles derived from the laboratory, these clinical studies provide important insights to guide the rational design of trials aimed at determining the clinical use of this approach to improving poststroke recovery.

Pharmacological management for agitation and aggression in people with acquired brain injury

BACKGROUND

Of the many psychiatric symptoms that may result from brain injury, agitation and/or aggression are often the most troublesome. It is therefore important to evaluate the efficacy of psychotropic medication used in its management.

OBJECTIVES

To evaluate the effects of drugs for agitation and/or aggression following acquired brain injury (ABI).

SEARCH STRATEGY

We searched MEDLINE (1966-2002), EMBASE (1980-2002) and the Cochrane Controlled Trials Register (1996-2002), Web of Science Citation Index, reference lists of papers meeting the inclusion criteria and recent reviews. We handsearched Brain Injury and the Journal of Head Trauma Rehabilitation. There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that evaluated the efficacy of drugs acting on the central nervous system for agitation and/or aggression, secondary to ABI, in participants over 10 years of age. Studies using lower levels of evidence (i.e. case series studies, single case studies and controlled group comparison studies), were collated in an appendix.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed trial quality. Authors were contacted where necessary for additional information. Studies of patients within six months after brain injury and/or in a confusional state, were distinguished from those of patients more than six months post-injury, or who were not confused.

MAIN RESULTS

Six randomised controlled trials were identified. Four RCTs evaluated the beta-blockers, propranolol and pindolol, one RCT evaluated the central nervous system stimulant, methylphenidate and one RCT evaluated amantadine, a drug normally used in parkinsonism and related disorders. The best evidence of effectiveness in the management of agitation and/or aggression following ABI was for beta-blockers. Two RCTs found propranolol to be effective (one study early and one late after injury). However, these studies used relatively small numbers, have not been replicated, used large doses, and did not use a global outcome measure or long-term follow-up. Comparing early agitation to late aggression, there was no evidence for a differential drug response. Firm evidence that carbamazepine or valproate is effective in the management of agitation and/or aggression following ABI is lacking.

REVIEWER'S CONCLUSIONS

Numerous drugs have been tried in the management of aggression in ABI but without firm evidence of their efficacy. It is therefore important to choose drugs with few side effects and to monitor their effect. Beta-blockers have the best evidence for efficacy and deserve more attention. The lack of evidence highlights the need for better evaluations of drugs for this important problem.

Prognostic factors in stroke rehabilitation: the possible role of pharmacological treatment

OBJECTIVES

The aim of the present study was to determine the impact of commonly used and potentially detrimental drugs on rehabilitation results and to clarify their role as prognostic factors.

MATERIAL AND METHODS

The study included 154 patients admitted to a rehabilitation hospital for sequelae of a first stroke. Multivariate analyses were performed using effectiveness of treatment, evaluated by both the Barthel Index (BI) and the Rivermead Mobility Index (RMI) and low response on both of these indexes as dependent variables. Independent variables were medical, demographic and pharmacological factors.

RESULTS

The use of detrimental drugs was negatively associated with effectiveness on both BI and RMI. Severity of stroke (Canadian Neurological Scale score at admission) and hemineglect were the other negative prognostic factors that significantly entered the analyses. On the other hand, the presence of Broca's aphasia positively influenced the recovery, essentially due to prolonged length of stay. The presence of detrimental drugs and hemineglect were associated with a higher risk of low response on both BI and RMI.

CONCLUSION

These findings confirm that the use of some drugs can influence rehabilitation results. Therefore, the choice of pharmacological treatment of stroke patients should be carefully evaluated by considering the potential detrimental effects of some drugs commonly used for the treatment of coincidental medical conditions.

Rehabilitation of persons with central nervous system tumors

A tumor that affects the central nervous system can have a dramatic impact on the individual affected, as well as his or her family and friends. The tumor, regardless of extent or location, may affect the physical, social, vocational, and emotional capabilities of the individual. Basic aspects of rehabilitation for patients with tumors affecting the brain and spinal cord are reviewed in this article. The authors have found that the same principles of neurorehabilitation applied to persons with traumatic brain injury, stroke, and traumatic spinal cord injury are equally appropriate for persons with brain and spinal cord tumors. These principles include the prevention of medical complications; the treatment of medical problems such as pain, spasticity, and neuropathic bowel and bladder; and the improvement of patients' mobility and activities of daily living. Rehabilitation specialists can help prevent complications, maximize function, and improve the quality of life for patients with central nervous system tumors.

Phenobarbital administration directed against kindled seizures delays functional recovery following brain insult

Anti-convulsant drug administration or recurrent seizures can impact functional recovery following brain insult. The nature of that impact depends on a variety of factors, including timing of drug administration and drug mechanism of action, as well as seizure number, timing, and severity. The objective of this study was to determine the functional consequences of anti-convulsant administration directed against seizure activity in brain-damaged animals. To this end, phenobarbital was coupled with daily electrical kindling of the amygdala beginning 48 h after a unilateral anteromedial cortex lesion. Recovery from somatosensory deficits was assessed, as was regional atrophy and basic fibroblast growth factor (bFGF) expression. Animals receiving phenobarbital prior to daily kindling failed to recover within 2 months of testing. In contrast, animals receiving saline prior to kindling as well as phenobarbital-treated non-kindled animals recovered within 2 months after the lesion. Though the exact mechanisms underlying these behavioral phenomena remain uncertain, patterns of bFGF expression among the groups provide some insight. Taken together, results from the present study suggest that anti-convulsant drug administration directed against subclinical seizure activity can be more detrimental to functional recovery than seizures alone or anti-convulsant drug treatment after seizure activity has occurred.

Effects of amphetamines and small related molecules on recovery after stroke in animals and man

Drugs modulating the levels of specific central neurotransmitters may influence both the rate and amount of functional recovery after focal brain injuries such as stroke. Because such drugs may be effective long after brain injury, the "therapeutic window" may be widened beyond the first few hour after stroke and an entirely new avenue for pharmacological intervention may be possible. The impact of drugs affecting norepinephrine and gamma-aminobutyric acid have been among the most extensively studied in the laboratory, and preliminary clinical data suggest similar effects in humans.

Studies on the influence of enriched-environment housing combined with systemic administration of an alpha2-adrenergic antagonist on spatial learning and hyperactivity after global ischemia in rats

BACKGROUND AND PURPOSE

The purpose of this study was to determine whether an enriched housing environment and/or systemic administration of the alpha2-adrenergic receptor antagonist atipamezole facilitate the rate of spatial learning after global ischemia in rats.

METHODS

Carotid arteries were closed for 20 minutes after permanent cauterization of vertebral arteries on the previous day. Enriched-environment housing and drug/saline treatment were begun 3 days after ischemia. For rehabilitation, housing in an enriched environment was combined with exploration in a labyrinth. Behavioral tests (the open-arena test and water-maze learning set task) were performed after 1-week periods of drug/saline treatment three times. In addition, the open-arena test was performed to evaluate the baseline level of animals 2 days after the induction of ischemia and at the end of the experiment, when the water-maze task was assessed in another room.

RESULTS

Rats housed in an enriched environment after ischemia showed better acquisition of the water-maze learning set task after 1 week of housing. The influence of atipamezole treatment on this parameter did not reach statistical significance. In the open-arena test, ischemic animals were slightly hyperactive; however, this symptom was eliminated by housing in an enriched environment.

CONCLUSIONS

The present data suggest that housing in an enriched environment facilitates the rate of spatial learning in rats with global ischemia. Rehabilitation also alleviated the hyperactivity observed in ischemic animals.

Cerebral and cerebellar diaschisis following carbamazepine therapy

1. The regional cerebral blood flow was studied by SPECT in patients with partial epilepsy before and after 30 days of monotherapy with carbamazepine (CBZ). 2. Both a qualitative visual interpretation and a semiquantitative analysis of SPECT was performed. All patients underwent EEG, CT scan, and MRI studies. The CBZ serum concentrations were assayed. 3. After therapy, in three patients with focal epilepsy, both a crossed cerebral and cerebellar diaschisis were observed, with respect to the side of the epileptic focus in the opposite hemisphere. No morphologic changes were detected at MRI in the cerebral or cerebellar remote hypometabolic areas found at SPECT. 4. CBZ may have a depressant action on the corticopontocerebellar pathways and on the corticocallosal connections.

Prescribing of potentially harmful drugs to patients admitted to hospital after head injury

Fundamental studies in laboratory animals show that certain drugs influence behavioural recovery after brain injury. Although some drugs have the potential to enhance recovery, others may be detrimental. The purpose of the present study was to determine how often these potentially detrimental drugs are used in the management of patients with traumatic brain injury. The medical records of 100 patients with head trauma admitted to a university hospital during one year were reviewed and the frequencies of medication prescriptions during the stay in hospital were recorded. Only 14% of patients with head injury were taking medications at the time of injury. All of the patients were prescribed medications during their stay in hospital. Seventy two per cent of the patients received one or a combination of the drugs (neuroleptics and other central dopamine receptor antagonists, benzodiazepines, and the anticonvulsants phenytoin and phenobarbitone) that animal studies suggest may impair recovery. Until the true impact of these classes of drugs on the recovery process is better understood, care should be exercised in their use.

Kindled seizures during a critical post-lesion period exert a lasting impact on behavioral recovery

The present study was undertaken to assess the effects of amygdala kindling on behavioral recovery following unilateral frontal cortex damage in rats. Daily electrical stimulation of the amygdala began 48 h after lesion and continued until all animals had a single Stage 5 seizure. When amygdala kindled seizure activity ratable as Stage 0 occurred within the first 6 days after lesion, animals recovered from somatosensory asymmetries in approximately 3 weeks. In contrast, kindled animals that experienced Stage 1 seizure activity within the first 6 days after lesion failed to recover from somatosensory deficits in 4 months of testing. Differences in rate of recovery could not be accounted for by lesion size or placement. These data support the notion that not only is there a 'critical period' after brain damage during which the recovery process is vulnerable to seizure activity, but the type of kindled seizure that is experienced during that time ultimately determines how recovery is affected.

Clonidine impairs recovery of beam-walking after a sensorimotor cortex lesion in the rat

Beam-walking in the rat is a useful model for studying the effects of drugs on motor recovery following brain injury. In the present experiment, the effect of clonidine HCl on beam-walking recovery was investigated. Groups of rats were first trained to traverse a narrow elevated beam and then subjected to a right sensorimotor cortex suction-ablation injury. After 24 h, each rat received a single dose of clonidine HCl (20, 60, or 200 micrograms/kg, i.p., salt weight) or saline. Recovery of beam-walking ability was scored over the next 12 days. Treatment with clonidine significantly slowed the rate of recovery (Kruskal-Wallis H = 8.755, df = 3; 0.02 less than P less than 0.05). Furthermore, the impairment persisted for at least 5 days after the rats were treated (Kruskal-Wallis H = 8.47, df = 3; 0.02 less than P less than 0.05). These data are consistent with the hypothesis that norepinephrine, working through central alpha 2-adrenergic receptors, influences motor recovery after a unilateral sensorimotor cortex lesion in the rat. Since many stroke patients are treated with centrally acting antihypertensive drugs, the potential effects of specific classes of these drugs during the recovery period, should be carefully considered.

Beam-walking in rats: studies towards developing an animal model of functional recovery after brain injury

While it has long been recognized that humans recover function after stroke or head injury, the direct impact of drugs on recovery has only recently received attention. The ability of rats to traverse a narrow, elevated beam has proven to be particularly useful when studying the effects of pharmacologic manipulations on motor recovery following cortical injury. However, the effect of testing conditions on the recovery of beam-walking performance has not been investigated. Treatment with amphetamine facilitated recovery of beam-walking following cortical lesions regardless of whether 'massed' or 'spaced' trials were employed. Unexpectedly, the performance of sham-operated controls declined when tested with 'massed' trials. 'Prodding' sham-operated rats by tapping on the rump abolished this decline in performance, but resulted in enhanced recovery in lesioned animals. The results indicate that testing conditions can exert a significant influence on beam-walking performance and are important to consider when interpreting the impact of pharmacologic agents on the recovery process.

Co-administration of Ro 15-1788 prevents diazepam-induced retardation of recovery of function

Following unilateral lesions of the anteromedial cortex, recovery from somatosensory asymmetry reliably occurs within about 10 days. Chronic exposure to diazepam significantly delays this recovery. In the present study, co-administration of Ro 15-1788, a benzodiazepine antagonist (i.e. it blocks the negative and positive allosteric modulation of GABA), prevented diazepam-induced retardation of recovery from somatosensory asymmetry. Nocturnal ambulatory (motor) activity was not different between rats receiving diazepam-alone and those receiving Ro 15-1788 in combination with diazepam. These data suggest that the benzodiazepine receptor is importantly involved in the detrimental effects of diazepam on recovery, and that non-specific behavior sedation plays little or no role.

Seizures and recovery from experimental brain damage

The effects of the gamma-aminobutyric acid antagonist, pentylenetetrazol (PTZ), on recovery from somatosensory and motor asymmetries after unilateral sensorimotor cortex lesions were investigated. Behavior was assessed using a bilateral tactile stimulation test and a measure of forelimb motor coordination. Immediately after surgery, the PTZ-treated and saline (SAL) control groups both exhibited severe ipsilateral behavioral asymmetries. Rats receiving PTZ recovered significantly faster from somatosensory asymmetry than those receiving SAL. Recovery was complete in the PTZ group within 3 postoperative weeks, while the SAL group failed to reach a comparable level until 2 months after surgery. There was no difference between PTZ and SAL groups on recovery of forelimb motor coordination. No difference in lesion size between the SAL and the PTZ groups could be found. These data are consistent with the hypothesis that post-traumatic neuronal depression may contribute to the severity of sensorimotor deficits observed after brain damage.

Anticonvulsant effect of intracortical, chronic infusion of GABA in kindled rats: focal seizures upon withdrawal

The behavioral and electrographic effects of chronic (7 days), localized infusion of GABA (100 micrograms/microliter) into the somatomotor cortex of fully amygdala-kindled rats is reported. The animals were stimulated once daily until a stage 5 (generalized clonic seizure) was obtained for five consecutive days. After determination of a stable seizure triggering threshold, the rats were implanted with osmotic minipumps (1 microliter/h for 7 days) connected to previously implanted bilateral cannulae. Amygdala stimulation was continued for 14 successive days. GABA infusion reduced the motor seizure without significantly modifying the limbic afterdischarge. This effect lasted until termination of drug application, with recovery of stage 5 convulsions on the following 3 to 5 days. No effects were observed in saline-infused animals or in rats with unilateral GABA treatment. Upon cessation of GABA treatment (removal of the osmotic devices by day 7 postimplantation), spontaneous epileptic discharges localized to the infusion sites appeared. In some animals, the abnormal activity was accompanied by behavioral signs of myoclonus. This cortical hyperexcitability lasted 2 to 24 h, with complete recovery afterward. These data indicate that two types of focal epilepsy may coexist independently in the same animal and provide confirmation of previous observations in the monkey on the existence of a "GABA-withdrawal syndrome" after chronic, focal infusion of the amino acid.

Recovery from GABA-mediated hemiplegia in young and aged rats: effects of catecholaminergic manipulations

We investigated the participation of catecholaminergic mechanisms in the functional recovery from motor cortex lesions in young (9 months) and aged (26 months) rats. The animals were studied during the recovery period from an hemiplegic syndrome secondary to small motor cortex lesions potentiated by the localized, chronic (7 days) infusion of GABA into the lesion site. Acute administration of haloperidol (0.1 mg/kg IP) to these recovered animals induced a re-emergence of the contralateral motor syndrome in both groups. In the young group, the haloperidol-induced hemiplegia lasted one day whereas in the aged animals the deficit was significantly prolonged lasting three days. Apomorphine administration (0.5 mg/kg IP) prior to or immediately after haloperidol injection failed to prevent or reverse the reappearance of the motor deficit. Adult animals recovered from motor cortex aspirations performed 7 to 12 months prior were refractory to haloperidol effects. Amphetamine administration to young rats treated chronically with saline or GABA infusion into the somatomotor region also failed to alter the clinical evolution of the motor deficit. The evidence suggests that dopaminergic mechanisms are involved in the functional recovery from brain lesions and that these mechanisms are most susceptible to neuroleptic blockade during the early post-lesional period. The deleterious effects of dopaminergic blockade are heightened in aged populations. The use of dopaminergic antagonists in brain-lesioned subjects, and particularly in geriatric populations, is considered potentially harmful, particularly in the early stages of the recovery process.

Epileptogenic gamma-aminobutyric acid-withdrawal syndrome after chronic, intracortical infusion in baboons

We studied the effects of chronic (7 days) infusion of GABA (100 micrograms/microliter) applied intracortically into the fronto-rolandic (FR) area of baboons, via osmotic minipumps. In photosensitive animals, bilateral GABA application produced a complete blockade of the paroxysmal discharges and associated clinical signs induced by intermittent light stimulation. Unilateral administration had similar effects, although these developed more gradually. At the end of the infusion period, both photosensitive and non-photosensitive animals showed a transitory state (3-4 days) of cortical hyperexcitability (spontaneous epileptogenic activity) localized to the infused area. The data indicate a role of GABA both in the natural photosensitivity of the epileptic baboon and in the withdrawal syndrome consecutive to the sudden interruption of chronically enhanced GABA levels in the FR territories of this monkey.