CRASH COURSE NEUROLOGY

xii,244 hlm; 18,5 x 26 c

Corpus callosotomy in refractory idiopathic generalized epilepsy

SummaryRationaleA small percentage of patients with idiopathic generalized epilepsy (IGE) do not respond to medical therapy. Generalized tonic–clonic (GTC) seizures are especially debilitating and can be associated with severe injuries. The benefit, safety and effect of corpus callosotomy (CC) in patients with IGE have not been studied.MethodsWe reviewed patients with presumed IGE who underwent CC between 1991 and 2000. Criteria for selection included history, examination, brain imagining, interictal and ictal EEG. All patients had refractory and debilitating tonic–clonic seizures (GTCS) and had failed four or more antiepileptic drugs. Seizure frequency was calculated per month over the last year and pre-operative baseline was compared to last follow-up using paired t-tests. IQ, executive function, language and verbal, non-verbal memory and quality of life (QOL) was compared before and after surgery. Serial EEGs after surgery were reviewed.ResultsThere were nine patients (seven men), mean age 37.9 (range: 22–49), mean IQ 87.3 (range: 75–107). All had anterior CC. Mean follow-up time was 5.4 years (range: 0.6–10.3 years). One patient died from sudden death in epilepsy 9 months after surgery. There was a significant reduction of GTC seizures from 6.3 to 1.1 (p<0.005). Four patients had more than 80% and eight more than 50% reduction. Of five patients with absence seizures, two became seizure free and one had more than 80% reduction and two worsened slightly, and of three with myoclonic seizures one had more than 90% reduction. One patient had completion of the CC with improvement of myoclonus and absence seizures, but not of GTC seizures and suffered a disconnection syndrome. Another had right frontal focal resection without improvement after new seizures of focal onset. Cognitive testing showed a good outcome (improved or no change) in all cognitive domains. Post-surgical EEG showed new focal slowing and sharp waves. There was no change in QOL.ConclusionCC can be effective in reducing GTC, absence and myoclonic seizures in patients with refractory IGE. These findings suggest that interhemispheric communication of the cerebral cortices plays an important role in the generation of seizures in IGE. Anterior CC appears safe while complete callosotomy has a risk of disconnection syndrome

Lamotrigine in Breast Milk and Nursing Infants: Determination of Exposure

OBJECTIVE: Although lamotrigine use during pregnancy has substantially increased over the past decade secondary to accumulated reproductive safety data, systematic data on lamotrigine during breastfeeding remains sparse. We sought to characterize the determinants of lamotrigine concentrations in breast milk and nursing-infant plasma. PATIENTS AND METHODS: Women who enrolled in a prospective investigation of perinatal medication pharmacokinetics, were treated with lamotrigine, and chose to continue lamotrigine while breastfeeding were included in the analysis. Breast milk samples were collected via breast pump from foremilk to hindmilk from a single breast to determine the excretion gradient and serial samples over 24 hours to determine the time course of excretion. Paired maternal/infant plasma samples were also collected. Lamotrigine concentrations in all of the samples were determined by using high-performance liquid chromatography with ultraviolet detection. Statistical analyses of breast milk and infant plasma concentrations and their determinants were conducted. RESULTS: Thirty women and their nursing infants participated in the study, providing a total of 210 breast milk samples. The mean milk/plasma ratio was 41.3%. There was a nonsignificant trend for higher lamotrigine concentrations in breast milk 4 hours after the maternal dose. Infant plasma concentrations were 18.3% of maternal plasma concentrations. The theoretical infant lamotrigine dose was 0.51 mg/kg per day, and the relative infant lamotrigine dose was 9.2%. Mild thrombocytosis was present in 7 of 8 infants at the time of serum sampling. No other adverse events were observed or reported in the breastfed infants. CONCLUSIONS: Consistent with previous investigations of medications in breast milk, the lamotrigine milk/plasma ratio is highly variable. The rate of lamotrigine excretion into human breast milk is similar to that observed with other antiepileptic drugs. These data expand the extant literature on lamotrigine in breastfeeding and demonstrate relatively comparable nursing-infant exposure to lamotrigine compared with other antiepileptic drugs

Cognitive Function at Three Years of Age After Fetal Exposure to Antiepileptic Drugs

Administration of antiepileptic drugs to pregnant animals in lower doses than those that produce congenital malformations is associated with cognitive and behavioral deficits and other poor neurodevelopmental outcomes. However, the effect of exposure of human fetuses to antiepileptic drugs on cognitive and behavioral abnormalities is unclear, and there are little data to guide the physician in choice of antiepileptic drugs in women who are pregnant or may become pregnant. This study is a planned interim analysis of data from the Neurodevelopmental Effects of Antiepileptic Drugs (NEAD) study, a prospective observational multicenter cohort study of the neurodevelopmental outcome at age 3 years of children who had been exposed in utero to one of several antiepileptic drugs. This study enrolled pregnant women with epilepsy who had been treated with carbamazepine, lamotrigine, phenytoin, or valproate between 1999 and 2004. The primary study outcome was cognitive performance of the children at 6 years of age. Of the 309 live births, cognitive assessments were conducted in 258 children.Children who had in utero exposure to valproate had significantly lower IQ scores than children exposed to the other antiepileptic drugs. After adjustment for maternal IQ, maternal age at delivery, drug dose, gestational age at birth, and maternal use of folate before conception, the mean IQ was 92 for children exposed to valproate, compared to 98 for those exposed to carbamazepine, 101 for those exposed to lamotrigine, and 99 for those exposed to phenytoin. The effect of in utero valproate exposure on IQ was dose dependent. Maternal IQ was strongly related to child IQ for each antiepileptic drug taken during pregnancy except valproate.The investigators conclude from these findings that valproate should not be a first-line antiepileptic in women of childbearing potential not only because of its known association with neural tube defects, but also because of its negative effect on cognitive impairment

Fetal antiepileptic drug exposure::Motor, adaptive, and emotional/behavioral functioning at age 3 years

The Neurodevelopmental Effects of Antiepileptic Drugs (NEAD) Study is an ongoing prospective observational multicenter study in the United States and United Kingdom that enrolled pregnant women with epilepsy on antiepileptic drug (AED) monotherapy from 1999 to 2004. The study seeks to determine if differential long-term neurodevelopmental effects exist across four commonly used AEDs (carbamazepine, lamotrigine, phenytoin, valproate). In this article, we examine fetal AED exposure effects on motor, adaptive, and emotional/behavioral functioning in 229 children who completed at least one of these tests at 3years of age. Adjusted mean scores for the four AED groups were in the low average to average range for motor functioning, parental ratings of adaptive functioning, and parental ratings of emotional/behavioral functioning. A significant dose-related performance decline in motor functioning was seen for both valproate and carbamazepine. A significant dose-related performance decline in parental ratings of adaptive functioning was also seen for valproate, with a marginal performance decline evident for carbamazepine. Further, parents endorsed a significant decline in social skills for valproate that was dose related. Finally, on the basis of parent ratings of attention span and hyperactivity, children of mothers who took valproate during their pregnancy appear to be at a significantly greater risk for a future diagnosis of attention-deficit/hyperactivity disorder. Additional research is needed to confirm these findings, examine risks of other AEDs, define the risks in the neonate associated with AEDs for treatment of seizures, and determine the underlying mechanisms of adverse AED effects on the immature brain. ► Children exposed in utero to higher dosages of valproate have lower motor/adaptive functioning. ► Children exposed in utero to higher dosages of carbamazepine have lower motor/adaptive functioning. ► Children exposed in utero to valproate may be at Increased risk for attention-deficit/hyperactivity disorder

Relationship of child IQ to parental IQ and education in children with fetal antiepileptic drug exposure

Clinical trial designs need to control for genetic and environmental influences when examining cognitive outcomes in children for whom clinical considerations preclude randomization. However, the contributions of maternal and paternal IQ and education to pediatric cognitive outcomes are uncertain in disease populations. The NEAD Study is an ongoing prospective observational multicenter study in the USA and UK, which enrolled pregnant women with epilepsy to determine if differential long-term neurodevelopmental effects exist across four commonly used antiepileptic drugs (AEDs). Here, we examined the relationship of IQ and education in both parents to child IQ at age 3 years. IQ and education for both parents were statistically correlated to child IQ. However, paternal IQ and education were not significant after accounting for maternal IQ effects. Because maternal IQ and education are independently related to child cognitive outcome, both should be assessed in studies investigating the effects of fetal drug exposures or other environmental factors that could affect the child’s cognitive outcome

Breastfeeding in children of women taking antiepileptic drugs: Cognitive outcomes at age 6 years

IMPORTANCE: Breastfeeding is known to have beneficial effects, but concern exists that breastfeeding during maternal antiepileptic drug (AED) therapy may be harmful. We previously noted no adverse effects of breastfeeding associated with AED use on IQ at age 3 years, but IQ at age 6 years is more predictive of school performance and adult abilities. OBJECTIVES: To examine the effects of AED exposure via breastfeeding on cognitive functions at age 6 years. DESIGN, SETTING, AND PARTICIPANTS: Prospective observational multicenter study of long-term neurodevelopmental effects of AED use. Pregnant women with epilepsy receiving monotherapy (ie, carbamazepine, lamotrigine, phenytoin, or valproate) were enrolled from October 14, 1999, through April 14, 2004, in the United States and the United Kingdom. At age 6 years, 181 children were assessed for whom we had both breastfeeding and IQ data. All mothers in this analysis continued taking the drug after delivery. MAIN OUTCOMES AND MEASURES: Differential Ability Scales IQ was the primary outcome. Secondary measures included measures of verbal, nonverbal, memory, and executive functions. For our primary analysis, we used a linear regression model with IQ at age 6 years as the dependent variable, comparing children who breastfed with those who did not. Similar secondary analyses were performed for the other cognitive measures. RESULTS: In total, 42.9% of children were breastfed a mean of 7.2 months. Breastfeeding rates and duration did not differ across drug groups. The IQ at age 6 years was related to drug group (P italic> .001 [adjusted IQ worse by 7–13 IQ points for valproate compared to other drugs]), drug dosage (regression coefficient, −0.1; 95% CI, −0.2 to 0.0; P = .01 [higher dosage worse]), maternal IQ (regression coefficient, 0.2; 95% CI, 0.0 to 0.4; P = .01 [higher child IQ with higher maternal IQ]), periconception folate use (adjusted IQ 6 [95% CI, 2–10] points higher for folate, P = .005), and breastfeeding (adjusted IQ 4 [95% CI, 0–8] points higher for breastfeeding, P = .045). For the other cognitive domains, only verbal abilities differed between the breastfed and nonbreastfed groups (adjusted verbal index 4 [95% CI, 0–7] points higher for breastfed children, P = .03). CONCLUSIONS AND RELEVANCE: No adverse effects of AED exposure via breast milk were observed at age 6 years, consistent with another recent study at age 3 years. In our study, breastfed children exhibited higher IQ and enhanced verbal abilities. Additional studies are needed to fully delineate the effects of all AEDs. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT0002186

Antiepileptic drug use in women of childbearing age

Research on antiepileptic drug (AED) teratogenesis has demonstrated an increased risk for valproate. The impact of these findings on current AED prescribing patterns for women of childbearing age with epilepsy is uncertain. The Neurodevelopmental Effects of Antiepileptic Drugs (NEAD) Study is an ongoing prospective multicenter observational investigation that enrolled pregnant women with epilepsy on the most common AED monotherapies from October 1999 to February 2004 (carbamazepine, lamotrigine, valproate, and phenytoin). A 2007 survey of AED use in women of childbearing age at eight NEAD centers found a total of 932 women of childbearing age with epilepsy (6% taking no AED, 53% monotherapy, 41% polytherapy). The most common monotherapies were lamotrigine or levetiracetam. Since 2004, prescriptions of carbamazepine, phenytoin, and valproate have decreased, whereas those for levetiracetam have increased. Except for the top two AED monotherapies, there were marked differences in other monotherapies and in polytherapies between U.S. and UK centers. Future investigations are needed to examine reasons for drug choice

Cognitive function at 3 years of age after fetal exposure to antiepileptic drugs

BACKGROUND: Fetal exposure of animals to antiepileptic drugs at doses lower than those required to produce congenital malformations can produce cognitive and behavioral abnormalities, but cognitive effects of fetal exposure of humans to antiepileptic drugs are uncertain. METHODS: Between 1999 and 2004, we enrolled pregnant women with epilepsy who were taking a single antiepileptic agent (carbamazepine, lamotrigine, phenytoin, or valproate) in a prospective, observational, multicenter study in the United States and the United Kingdom. The primary analysis is a comparison of neurodevelopmental outcomes at the age of 6 years after exposure to different antiepileptic drugs in utero. This report focuses on a planned interim analysis of cognitive outcomes in 309 children at 3 years of age. RESULTS: At 3 years of age, children who had been exposed to valproate in utero had significantly lower IQ scores than those who had been exposed to other antiepileptic drugs. After adjustment for maternal IQ, maternal age, antiepileptic-drug dose, gestational age at birth, and maternal preconception use of folate, the mean IQ was 101 for children exposed to lamotrigine, 99 for those exposed to phenytoin, 98 for those exposed to carbamazepine, and 92 for those exposed to valproate. On average, children exposed to valproate had an IQ score 9 points lower than the score of those exposed to lamotrigine (95% confidence interval [CI], 3.1 to 14.6; P = 0.009), 7 points lower than the score of those exposed to phenytoin (95% CI, 0.2 to 14.0; P = 0.04), and 6 points lower than the score of those exposed to carbamazepine (95% CI, 0.6 to 12.0; P = 0.04). The association between valproate use and IQ was dose dependent. Children’s IQs were significantly related to maternal IQs among children exposed to carbamazepine, lamotrigine, or phenytoin but not among those exposed to valproate. CONCLUSIONS: In utero exposure to valproate, as compared with other commonly used antiepileptic drugs, is associated with an increased risk of impaired cognitive function at 3 years of age. This finding supports a recommendation that valproate not be used as a first-choice drug in women of childbearing potential