Prevention of post-traumatic epilepsy

Neuroprotective, Neuroplastic, and Neurobehavioral Effects of Daily Treatment With Levetiracetam in Experimental Traumatic Brain Injury

Background. Prophylactic treatment with antiepileptic drugs (AEDs) has been recommended to prevent early seizure onset in patients with traumatic brain injury (TBI). However, the potential neuroprotective and/or detrimental effects of prophylactic AED treatment on behavioral and cognitive function after TBI are not well studied. Objective. To investigate the effects of a novel AED, levitiracetam (LEV), on behavioral and cognitive function after experimental TBI in rats. Methods. Adult male rats were administered LEV (intraperitoneal 50 mg/kg) or vehicle (saline; SL) daily for 20 days beginning 1 day after controlled cortical impact (CCI; 2.8 mm; 4 m/s) or sham surgery. Beam performance (days 1-6), Y-maze (day 7), and Morris water maze (days 14-19) postinjury testing was assessed. Results. Daily LEV treatment improved motor function, increased novel arm exploration in the Y-maze, elicited greater hippocampal cell sparing, and decreased contusion volumes compared with CCI/SL rats. Daily LEV administration also reversed a TBI-induced decrease in regional glutamate transporter expression and neuroplastic marker proteins present 20 days post-CCI. Also, daily LEV treatment decreased regional IL-1β expression after TBI. Conclusions. These results suggest that daily LEV treatment has beneficial effects on histological, molecular, and behavioral elements of neurological recovery after TBI, in part, via modulation of neuroinflammatory and excitatory pathways.

Management of provoked seizure

A provoked seizure may be due to structural damage (resulting from traumatic brain injury, brain tumor, stroke, tuberculosis, or neurocysticercosis) or due to metabolic abnormalities (such as alcohol withdrawal and renal or hepatic failure). This article is a part of the Guidelines for Epilepsy in India. This article reviews the problem of provoked seizure and its management and also provides recommendations based on currently available information. Seizure provoked by metabolic disturbances requires correction of the triggering factors. Benzodiazepines are recommended for treatment of seizure due to alcohol withdrawal; gabapentin for seizure seen in porphyria; and antiepileptic drugs (AED), that are not inducer of hepatic enzymes, in the seizures seen in hepatic dysfunction. In severe traumatic brain injury, with or without seizure, phenytoin (PHT) may be given for 7 days. In ischemic or hemorrhagic stroke one may individualize the AED therapy. In cerebral venous sinus thrombosis (CVST), AED may be prescribed if there is seizure or computed tomographic (CT) abnormalities or focal weakness; the treatment, in these cases, has to be continued for 1 year. Prophylactic AED is not recommended in cases of brain tumor and neurosurgical procedures and if patient is on an AED it can be stopped after 1 week.

Serotonin-dopamine antagonism ameliorates impairments of spontaneous alternation and locomotor hyperactivity induced by repeated electroconvulsive seizures in rats

We have shown that seven consecutive administrations of electroconvulsive shock (ECS) produce impairment of spontaneous alternation behavior in a Y-maze test and a locomotor hyperactivity in an open-field test even 24h after the last administration in rats. To clarify the mechanisms of the behavioral impairments, we investigated the effect of drugs acting on dopaminergic and serotonergic nervous systems. The dopamine-2 (D(2)) receptor antagonists haloperidol and sulpiride abolished locomotor hyperactivity, but did not show effects on the impairment of spontaneous alternation behavior. The serotonin-2 (5-HT(2)) receptor antagonist ketanserin suppressed the impairment of spontaneous alternation behavior without affecting locomotor hyperactivity. The 5-HT(2) and D(2) receptor antagonist risperidone significantly ameliorated both behavioral impairments. These results suggest that 5-HT(2) receptors and D(2) receptors are associated with repeated ECS-induced impairment of spontaneous alternation behavior and locomotor hyperactivity, respectively.

Cognitive progression in epilepsy

The issue of cognitive progression in people with epilepsy is of considerable interest and has important clinical and theoretical implications. In this paper, we review recent studies in both the adult and childhood epilepsy literature which have included a longitudinal test-retest design to examine this question. Several important methodological issues of this literature are highlighted and areas which require more investigation are identified.

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.

Pharmacological prophylaxis of post-traumatic epilepsy

Early and late epileptic seizures are a frequent complication of severe head traumas. The administration of anticonvulsant drugs immediately after head injury is commonly implemented as a prophylactic measure; however, there is a lack of consensus on the usefulness of prophylaxis with anticonvulsants for the prevention of late post-traumatic epilepsy (PTE). The inconsistent evidence accumulated so far from clinical studies, most nonrandomised and uncontrolled in design, and the limited knowledge of the processes underlying post-traumatic epileptogenesis, do not warrant empirical pharmacological prophylaxis with long term administration of conventional anticonvulsants. Phenytoin and phenobarbital (phenobarbitone) are used to a large extent in this indication. As a general rule, a benefit/risk analysis in individual patients should drive prophylactic drug prescription in PTE as it can have potential detrimental effects on a patient's recovery. New compounds, such as free-radical scavengers and antiperoxidants, show encouraging experimental results, but their clinical use is still very limited.

Prognostic factors in the occurrence of posttraumatic epilepsy after penetrating head injury suffered during military service

In this retrospective study, the authors evaluated confounding risk factors, which are allegedly influential in causing unprovoked posttraumatic epilepsy, in 489 patients from the frontlines of the Iran–Iraq War.

Four hundred eighty-nine patients were followed for 6 to154 months (mean 39.4 months, median 23 months), and important factors precipitating posttraumatic epilepsy were evaluated using uni- and multivariate regression analysis.

One hundred fifty-seven (32%) of 489 patients became epileptic during the study period. The results of univariate analysis indicated a significant relationship between epilepsy and Glasgow Outcome Scale (GOS) score (X2 = 76.49, p < 0.0001, df = 2), Glasgow Coma Scale score at admission (X2 = 19.48, p < 0.0001, df = 3), motor deficit (X2 = 11.79, p < 0.001, df = 1), mode of injury (X2 = 10.731, p < 0.05), transventricular injury (X2 = 6.9, p < 0.008, df = 1), dysphasia (X2 = 5.3, p < 0.02), central nervous system infections (X2 = 5.3, p < 0.02), and early-onset seizures (X2 = 4.1, p < 0.04, df = 1). The results of multivariate analysis, on the other hand, indicated that the GOS score and motor deficit were of greater statistical importance (X2 = 35.24, p < 0.0001; and X2 = 7.1, p < 0.07, respectively). Factors that did have much statistically significant bearing on posttraumatic epilepsy were the projectile type, site of injury on the skull, patient age, number of affected lobes, related hemorrhagic complications, and retained metallic or bone fragments.

Glasgow Outcome Scale score and focal motor neurological deficit are of particular importance in predicting posttraumatic epilepsy after missile head injury.

Predictors and dynamics of posttraumatic epilepsy

OBJECTIVES

The goal of our study was to identify clinical, neurophysiological and neuroradiological variables in severe head trauma (SHT) with predictive value for posttraumatic epilepsy (PTE) and to evaluate the influence of each risk factor for the dynamics of epilepsy.

MATERIALS AND METHODS

We systematically compared 57 PTE patients with 50 age and sex-matched control patients with SHT and no PTE. Mean follow-up was 8 years.

RESULTS

Of all PTE-patients 68.5% had their first seizure within 2 years after the trauma. Significant risk factors for PTE were focal signs in the first examination (P < 0.01), missile injuries (P < 0.01), frontal lesions (P < 0.01), intracerebral hemorrhage (P < 0.01), diffuse contusion (P < 0.01), prolonged posttraumatic amnesia (P < 0.001), depression fracture (P < 0.01) and cortical-subcortical lesions (P < 0.001). The combination of the last 3 variables conferred a particularly high risk for PTE (logistic regression analysis). Combined seizure pattern, high seizure frequency, AED-noncompliance and alcohol abuse predicted poor seizure control.

CONCLUSION

The risk for PTE is clearly determined by those variables which correlate with the severity, the extent of tissue loss and the penetrating nature of the brain trauma.

The management of epilepsy in the 1990s. Acquisitions, uncertainties and priorities for future research

The pharmacological treatment of epilepsy has made considerable progress during the last decade, due to improved knowledge of the clinical pharmacology of individual drugs, acquisition of new information on the factors affecting response and need for drug treatment, and development of promising new agents. Once a clinical diagnosis of epilepsy has been made (which generally requires the occurrence of more than one seizure), treatment should be started with a single drug selected on the basis of seizure type and tolerability profile. Although there are important regional differences in prescribing patterns and individual circumstances may dictate alternative choices, carbamazepine is generally regarded as the preferred treatment for partial seizures (with or without secondary generalisation) while valproic acid (sodium valproate) is usually the first choice in most forms of generalised epilepsies. To achieve therapeutic success, the daily dosage must be tailored to meet individual needs, and there is suggestive evidence that in some patients the dosage prescribed initially may be unnecessarily large. Plasma antiepileptic drug concentrations may aid in the individualization of dosage, but should not be regarded as a substitute for careful monitoring of clinical response. Although overall about 70% of patients can be completely controlled, response rate is influenced by a number of factors, the most important of which are seizure type and syndromic form. The importance of a correct syndromic classification for rational drug selection has been poorly assessed and represents a major area for future research. Patients who do not respond to the highest tolerated dose of the initially prescribed drug may be switched to monotherapy with an alternative agent or may be given add-on treatment with a second drug. Appropriate prospective trials are required to assess the merits of either strategy. If add-on therapy is selected and the patient becomes seizure free, it may be possible to discontinue the drug prescribed initially and reinstitute monotherapy. Only a minority of patients are likely to require multiple drug therapy, and it remains to be established whether specific drug combinations are more effective than others. Until further information becomes available, the new agents should be reserved for patients failing to respond to the conventional treatments of first choice. Patients whose seizures cannot be controlled by available drugs should be reassessed, and polytherapy should be maintained only when there is clear evidence that benefits outweigh possible adverse effects. In many patients who have been seizure free for at least 2 years it may be possible to gradually discontinue all medications.(ABSTRACT TRUNCATED AT 400 WORDS)

Inhibition of adenylyl cyclase in rat striatal homogenates by combinations of dopamine and ferric iron compounds

The adenylyl cyclase activity of homogenates of striatal tissue from rat brain has been used as a model to test the hypothesis that the products of the reaction of polyphenols with ferric iron compounds are toxic. Dopamine (DA), at levels that stimulate adenylyl cyclase, inhibited the activity in the presence of 2 mol of potassium ferricyanide (FC), methemoglobin or ferricytochrome c per mol of DA. Combinations of potassium ferrocyanide and DA were not inhibitory. Neither pyrocatechol nor hydroquinone stimulated the activity, but these polyphenols were inhibitory in the presence of FC. Tyramine, phosphorylated DA or phosphorylated pyrocatechol had no effect on the activity of the enzyme in the presence or absence of FC. Forskolin was unable to stimulate the adenylyl cyclase once the latter was inhibited by DA plus FC, and dithiothreitol could not reverse inhibition by DA plus FC. Incubation of DA with FC, in the absence of the homogenate, resulted in substances that were not inhibitory. These findings suggest that the polyphenols plus FC react to yield substances that inhibit the adenylyl cyclase by affecting the catalytic unit of the enzyme complex.

Alcohol-related seizures, Part II: Clinical presentation and management

Alcoholism may be society's most devastating problem short of war and malnutrition. Perhaps the most complex and preplexing medical complication of alcoholism is alcohol-related seizures. This article is a collective review designed to provide emergency physicians with an overview of the topic that is pertinent to their clinical practice. Part 1 addressed the pathophysiology, differential diagnosis, and evaluation of alcohol-related seizures. Part 2 focuses on the clinical presentation, management, and disposition. In addition, a classification of alcohol-related seizures is proposed.

Alcohol-related seizures, Part I: Pathophysiology, differential diagnosis, and evaluation

Alcoholism may be society's most devastating problem short of war and malnutrition. Perhaps the most complex and perplexing medical complication of alcoholism is alcohol-related seizures. This article is a collective review designed to provide emergency physicians with an overview of the topic that is pertinent to their clinical practice. Part 1 addresses the pathophysiology, differential diagnosis, and evaluation of alcohol-related seizures. Part 2 will concentrate on the clinical presentation, management, and disposition. In addition, a classification of alcohol-related seizures will be proposed.

Clinical predictors of post-traumatic seizures in children with head trauma

STUDY OBJECTIVES

To determine the clinical characteristics associated with early post-traumatic seizures in children with head trauma. DESIGN, SETTING, AND TYPE OF PARTICIPANTS: Retrospective chart review; urban trauma center/pediatric emergency department. Trauma patients aged 3 months to 15 years given discharge diagnosis ICD-9-CM codes indicating head trauma and seen from 1988 to 1990 were eligible for the study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 194 patients, 96% suffered blunt trauma and 53% had a loss of consciousness. Fifty-one percent of 141 computed tomography (CT) scans of the head were abnormal, most frequently demonstrating skull fractures (34%), subdural hematomas (15%), and cerebral contusions (14%). Eighteen patients (9.3%) suffered post-traumatic seizures. A loss of consciousness, a low Glasgow Coma Scale (GCS) score (3 to 8), and an abnormal CT scan were associated with post-traumatic seizures (P < .02, .001, and .02, respectively). However, only a low GCS score was predictive of post-traumatic seizures when these factors were considered simultaneously (P < .001), with 38.7% of patients with low GCS scores suffering post-traumatic seizures and 3.8% of patients with high GCS scores suffering post-traumatic seizures. In children with low GCS scores, treatment with phenytoin was associated with a decrease in post-traumatic seizures.

CONCLUSION

In the pediatric head trauma patient, a GCS score of 3 to 8 appears to be predictive of post-traumatic seizures. The data from this retrospective study are consistent with the hypothesis that prophylactic phenytoin reduces post-traumatic seizures in the pediatric head trauma patient with a low GCS score.