Neurodevelopmental effects of anti-epileptic drugs

Postencephalitis epilepsy in children: Diurnal rhythm of seizures is related to clinical characteristics

OBJECTIVES

The objective of the study was to summarize the relationship between the clinical features of children with postencephalitis epilepsy and the diurnal rhythm of seizures.

METHODS

We collected a retrospective review of 44 patients between 0 and 14 years, who were diagnosed with postencephalitis epilepsy. Patients were divided into three groups by their seizures in day/night or wakefulness/sleep state.

RESULTS

Most epileptic seizures of patients of age 3 years or younger occurred during the daytime, and the other occurred most frequently at night. Most epileptic seizures of boys occurred during the wakefulness state, and girls occurred most frequently in sleep. Seizures of patients with the first seizure in the daytime occurred more frequently during the daytime and the wakefulness state; on the contrary, the first seizure in the nighttime occurred more frequently during the nighttime and the sleep state. Tonic seizure occurred more often during the nighttime and in sleep; epileptic spasm occurred more frequently during the daytime and wakefulness. Most seizures of temporal origin occurred in the awakening. The seizures of patient occurred more often during the wakefulness state; the prognosis was worse. Patients with the peak of seizures in the daytime, the level of the physiological development were poorer.

CONCLUSIONS

The diurnal rhythm of seizures is different in patients with postencephalitis epilepsy with different clinical characteristics (age, gender, time of first seizure, seizure pattern, electroencephalography (EEG), prognosis, and physiological development). Our results may assist in seizure prediction, individualized treatment patterns, and prognosis prediction.

Risk factors for recurrence after drug withdrawal in childhood epilepsy

BACKGROUND

Several studies have been conducted to determine the risk of recurrence after withdrawal of antiepileptic drugs (AEDs) in recent years. There is no consensus concerning the circumstances affecting discontinuation of AEDs. This study was designed to determine the recurrence rate of epilepsy after withdrawal of AEDs and the risk factors related with recurrence.

METHODS

Children with epilepsy onset between 1 month and 16 years of age who were followed up at least 3 years after AED treatment withdrawal were enrolled. Patients were classified into groups according to defined risk factors for recurrence.

RESULTS

A total of 284 patients, 137 (48.2%) girls and 147 (51.8%) boys were included, and seizures recurred after withdrawal in 51 patients (18%). Thirty-three (64.7%) patients had recurrence in the first year after withdrawal. The recurrence risk was calculated based on the electro-clinical syndromes classification; the recurrence risk was the highest in the juvenile myoclonic/absence group and lowest in the benign infantile seizure group. No recurrence was observed in the infantile spasm group. Data evaluated by multivariable analysis showed that having the structural-metabolic and unknown epilepsy and <3 years seizure free period before withdrawal of AEDs were the main risk factors for recurrence after AED withdrawal in our study.

CONCLUSION

We suggest a seizure-free period of at least 3 years under AED medication and we must be cautious in patients with structural-metabolic and unknown epilepsy before AED withdrawal.

The role of task-based neural activation research in understanding cognitive deficits in pediatric epilepsy

Children with epilepsy can experience significant cognitive dysfunction that can lead to academic underachievement. Traditionally believed to be primarily due to the effects of factors such as the chronicity of epilepsy, medication effects, or the location of the primary epileptogenic lesion;, recent evidence has indicated that disruption of cognition-specific distributed neural networks may play a significant role as well. Specifically, over the last decade, researchers have begun to characterize the mechanisms underlying disrupted cognitive substrates by evaluating neural network abnormalities observed during specific cognitive tasks, using task-based functional magnetic resonance imaging (fMRI). This targeted review assesses the current literature investigating the relationship between neural network abnormalities and cognitive deficits in pediatric epilepsy. The findings indicate that there are indeed neural network abnormalities associated with deficits in executive function, language, processing speed, and memory. Overall, cognitive dysfunction in pediatric epilepsy is associated with a decrease in neural network activation/deactivation as well as increased recruitment of brain regions not typically related to the specific cognitive task under investigation. The research to date has focused primarily on children with focal epilepsy syndromes with small sample sizes and differing research protocols. More extensive research in children with a wider representation of epilepsy syndromes (including generalized epilepsy syndromes) is necessary to fully understand these relationships and begin to identify underlying cognitive phenotypes that may account for the variability observed across children with epilepsy. Furthermore, more uniformity in fMRI protocols and neuropsychological tasks would be ideal to advance this literature.

Pediatric epilepsy surgery: could age be a predictor of outcomes?

OBJECTIVE Like adults, many children suffering from intractable seizures benefit from surgical therapy. Although various reports indicate that early intervention may avoid severe developmental consequences often associated with intractable epilepsy, surgery is still considered a last option for many children. In this retrospective study, the authors aimed to determine whether pediatric epilepsy surgery, in particular during the first years of life, relates to measurable benefits. METHODS Data from 78 patients (age range 5 months to 17 years) who underwent epilepsy surgery at the Geneva and Lausanne University Hospitals between 1997 and 2012 were reviewed retrospectively. Patients were dichotomized into 2 groups: infants (≤ 3 years of age, n = 19), and children/adolescents (4-17 years of age, n = 59). Compared with children/adolescents, infants more often had a diagnosis of dysplasia (37% vs 10%, respectively; p < 0.05, chi-square test). RESULTS The overall seizure-free rate was 76.9%, with 89.5% in infants and 72.9% in the children/adolescents group. Infants were 2.76 times as likely to achieve seizure-free status as children/adolescents. Postoperative antiepileptic medication was reduced in 67.9% of patients. Only 11.4% of the patients were taking more than 2 antiepileptic drugs after surgery, compared with 43% before surgery (p < 0.0001). The overall complication rate was 15.1% (6.4% transient hemiparesis), and no major complications or deaths occurred. CONCLUSIONS The data show a high seizure-free rate in children ≤ 3 years of age, despite a higher occurrence of dysplastic, potentially ill-defined lesions. Pediatric patients undergoing epilepsy surgery can expect a significant reduction in their need for medication. Given the excellent results in the infant group, prospective studies are warranted to determine whether age ≤ 3 years is a predictor for excellent surgical outcome.

Effects of chronic administration of gabapentin and carbamazepine on the histomorphology of the hippocampus and striatum

Background

Antiepileptic drugs used to avert epileptic seizures necessitate prolonged duration for improved efficacy and could induce some side effects.

Purpose

The present study investigated the effect of chronic administration of two common antiepileptic drugs – gabapentin and carbamazepine, on the histomorphology of the hippocampus and striatum in adult rats.

Methods

25 adult male Wistar rats were grouped randomly into 5 groups. 3 groups were administered either therapeutic doses of gabapentin (16 mg/kg) or carbamazepine (20 mg/kg) or sub-therapeutic dose of gabapentin plus carbamazepine (8 + 10 mg/kg). To confirm anticonvulsant effects, these animals were kindled for seizures at sub-maximal electroshock. Appropriate negative and positive controls were given normal saline. At the end of treatment, brain tissues were obtained and processed for histological procedures.

Results

The study confirm significant decrease (P<0.001) in convulsion parameters tonic flexion, tonic extension and clonic convulsion, between drug treated groups and electroshock control. Histological studies revealed significant increase (p<0.001) in neurons showing features of degeneration in the hippocampus, for drug treated groups as compared to normal and electroshock control. Also, drug treatment reduced nissl activity in both hippocampus and striatum.

Conclusion

Chronic administration of gabapentin and carbamazepine may cause increase in neurodegenerative changes in the adult brain.

[Neuroprotection with hypothermia in the newborn with hypoxic-ischaemic encephalopathy. Standard guidelines for its clinical application]

Standardisation of hypothermia as a treatment for perinatal hypoxic-ischaemic encephalopathy is supported by current scientific evidence. The following document was prepared by the authors on request of the Spanish Society of Neonatology and is intended to be a guide for the proper implementation of this therapy. We discuss the difficulties that may arise when moving from the strict framework of clinical trials to clinical daily care: early recognition of clinical encephalopathy, inclusion and exclusion criteria, hypothermia during transport, type of hypothermia (selective head or systemic cooling) and side effects of therapy. The availability of hypothermia therapy has changed the prognosis of children with hypoxic-ischaemic encephalopathy and our choices of therapeutic support. In this sense, it is especially important to be aware of the changes in the predictive value of the neurological examination and the electroencephalographic recording in cooled infants. In order to improve neuroprotection with hypothermia we need earlier recognition of to recognise earlier the infants that may benefit from cooling. Biomarkers of brain injury could help us in the selection of these patients. Every single infant treated with hypothermia must be included in a follow up program in order to assess neurodevelopmental outcome.

Perioperative seizure incidence and risk factors in 223 pediatric brain tumor patients without prior seizures

OBJECT

The incidence of, and risk factors for, perioperative seizures and the need for perioperative antiepileptic drugs (AEDs) in previously seizure-free children with brain tumors remains unclear. The authors have undertaken a review of previously seizure-free pediatric patients with brain tumors undergoing resection to identify the incidence of seizures in the perioperative period, and to characterize risk factors for perioperative seizures in this population.

METHODS

A retrospective review was conducted of all patients between 0 and 19 years of age without prior seizures who underwent intracranial tumor resection at the authors' institution between January 2005 and December 2009.

RESULTS

Of the 223 patients undergoing 229 operations, 7.4% experienced at least 1 clinical seizure during the surgical admission. Over half of all tumors were supratentorial. Only 4.4% of patients received prophylactic AEDs. Independent factors associated with perioperative seizures included supratentorial tumor, age < 2 years, and hyponatremia due to syndrome of inappropriate antidiuretic hormone or cerebral salt wasting. Tumor type, lobe affected, operative blood loss, and length of surgery were not independently associated with seizure incidence.

CONCLUSIONS

Perioperative seizures in previously seizure-free children undergoing resection of brain tumors are associated with supratentorial tumor location, age < 2 years, and postoperative hyponatremia. Perioperative seizures are not associated with tumor pathology, tumor size, or frontotemporal location. Due to the low incidence of seizures in this series in patients more than 2 years old with normal serum sodium, the authors recommend that pediatric patients with brain tumors not routinely receive perioperative prophylactic AEDs. However, the role for prophylaxis in patients younger than 2 years of age deserves further study.

Etiological analysis of neurodevelopmental disabilities: single-center eight-year clinical experience in south China

Etiology determination of neurodevelopmental disabilities (NDDs) currently remains a worldwide common challenge on child health. We herein reported the etiology distribution feature in a cohort of 285 Chinese patients with NDDs. Although concrete NDD etiologies in 48.4% of the total patients could not be identified, genetic diseases (with the proportion of 35.8% in the total cases) including inborn errors of metabolism (IEM) and congenital dysmorphic diseases, constituted the commonest etiology category for NDDs in this study. The two key experimental technologies in pediatric metabolomics, gas chromatography-mass spectrometry (GC-MS), and tandem mass spectrometry (MS-MS), proved to be substantially helpful for the exploration of the NDD etiologies in this clinical investigation. The findings in this paper provided latest epidemiologic information on the etiology distribution of NDDs in Chinese, and the syndromic NDDs caused by citrin deficiency and the novel chromosomal karyotype, respectively, further expanded the etiology spectrum of NDDs.