Neuropsychological outcomes in children of mothers with epilepsy

Cognitive outcomes after fetal exposure to carbamazepine, lamotrigine, valproate or levetiracetam monotherapy: Data from the EURAP neurocognitive extension protocol

PURPOSE

Prenatal exposure to antiseizure medications (ASMs) has been associated with an increased risk of major malformations and neurodevelopmental disorders, with the latter being mainly associated with valproate (VPA). Our aim was to compare neurocognitive outcome at age 6-7 years in children exposed prenatally to lamotrigine (LTG), carbamazepine (CBZ), valproate (VPA) or levetiracetam (LEV) monotherapy.

METHODS

Eligible mother-child pairs were identified from the observational prospective multinational EURAP cohort study. Assessor-blinded testing was conducted at age 6-7 years using WISC-III and NEPSY-II. Verbal IQ (VIQ), performance IQ (PIQ), full scale IQ (FSIQ) and performance in neuropsychological tasks were compared across ASM groups by ANOVA. Scores were adjusted for maternal IQ, paternal education, maternal epilepsy type and child sex.

RESULTS

Of 169 children enrolled in the study, 162 (LTG n = 80, CBZ n = 37, VPA n = 27, LEV n = 18) had sufficient data from WISC-III, NEPSY-II or both, and were included in the analyses. Observed (unadjusted) PIQ and FSIQ did not differ across exposure groups, but a difference was identified for VIQ (P<0.05), with children exposed to VPA having lower scores than children exposed to LEV (P<0.05) and children from all groups combined (P<0.01). Adjusted VIQ, PIQ and FSIQ scores did not differ significantly across groups, but VPA-exposed children had borderline significantly lower adjusted VIQ scores than children from all groups combined (P=0.051). VPA-exposed children had lower scores in comprehension of instructions before and after adjustment for confounding variables than children exposed to LTG (P<0.001), LEV (P<0.01) or children from all groups combined (p < 0.001). The VPA-exposed group also had lower scores in immediate and delayed memory for faces compared to children exposed to CBZ (P<0.05 and P<0.001, respectively) and LTG (P<0.05 and P<0.02, respectively), and children from all groups combined (P<0.02 and P<0.001, respectively). LEV-exposed children had lower scores in delayed memory for names than children exposed to LTG (P<0.001), CBZ (P<0.001), VPA (P<0.05) and children from all groups combined (P<0.001).

CONCLUSIONS

Consistent with previous reports, our results provide evidence for an adverse effect of prenatal exposure to valproate on verbal development. Our finding of relatively weaker performance of VPA-exposed children compared to other ASM exposures in both comprehension of instructions and face memory also suggest that children of mothers treated with VPA are at increased risk for compromised memory functions or altered processing of socially relevant information.

Impaired executive functioning in children of women with epilepsy

OBJECTIVE

While neurodevelopmental symptoms are often seen in children of mothers with epilepsy, research specifically addressing executive function (EF) in this population is limited. This study aims to investigate EF in children of mothers with epilepsy, both with and without fetal exposure to anti-seizure medications, compared to typically developing children whose mothers do not have epilepsy.

METHODS

We evaluated EF in children aged 8 to 17 years born to mothers with clinically validated diagnoses of epilepsy, using the Behavior Rating Inventory of Executive Function completed by the mothers. The results were then compared to a typically developing control group at the same age living in the same geographic area.

RESULTS

The results showed significantly higher levels of EF problems in children of mothers with epilepsy who were exposed (p = 0.005, d = 0.63), and unexposed (p = 0.001, d = 0.74) to anti-seizure medications during pregnancy, compared to typically developing children. There was no significant difference in EF problems between the exposed and unexposed groups. These findings remained statistically significant after adjusting for mothers' education levels, and when excluding participants exposed to valproate during pregnancy.

SIGNIFICANCE

This study highlights the increased risk of EF problems in children of mothers with epilepsy, independent of exposure to anti-seizure medications. Findings underscore the importance of continuous monitoring of EF in these children and highlights the need for further research into the diverse factors affecting EF development in this group.

Neurocognition after prenatal levetiracetam, lamotrigine, carbamazepine or valproate exposure

OBJECTIVE

To examine neurocognitive functioning of children exposed prenatally to carbamazepine, lamotrigine, levetiracetam or valproate monotherapy.

METHODS

In a prospective observational study, children aged 6 or 7 years, identified from the European Registry of Antiepileptic Drugs and Pregnancy database in The Netherlands, were assessed using the Wechsler Intelligence Scale for Children and the developmental neuropsychological assessment. Maternal IQ was measured using Wechsler Adult Intelligence Scale. Assessors were blinded to drug exposures.

RESULTS

One hundred and sixty-one children (one set of twins and 21 sibling pairs) of 139 mothers were included. As a group, children achieved average scores on neurocognitive outcomes. Children exposed to valproate (n = 22) performed lower on all six neurocognitive domains, especially language, than those exposed to carbamazepine (n = 32), lamotrigine (n = 82) or levetiracetam (n = 25). After controlling for maternal IQ and drug dose, the verbal IQ of valproate-exposed children was on average 9.1 points lower than those exposed to carbamazepine (95% confidence interval [CI] 1.3-17.0; p = 0.023), 10.3 lower than lamotrigine-exposed children (CI 3.4-17.3; p = 0.004) and 13.4 lower than levetiracetam-exposed children (CI 5.2-21.6; p = 0.002). No significant dose-effect was found. Virtually no significant differences were found between lamotrigine and levetiracetam or lamotrigine and carbamazepine exposed children.

CONCLUSIONS

Consistent with previous research, valproate-exposed children experienced more problems compared to three other common antiepileptic drugs, while children exposed to lamotrigine, carbamazepine or levetiracetam revealed little to no problems. This illustrates the need for systematic follow-up of prenatally exposed children, to support pre-pregnancy counseling and treatment decisions in women of reproductive age.

Peripartum management of bipolar disorder: what do the latest guidelines recommend?

INTRODUCTION

Many women with bipolar disorder experience significant morbidity during pregnancy and the postpartum period. The use of evidence-based and up-to-date guidelines has the potential to improve maternal and neonatal care. We review the latest clinical practice guidelines to gather recommendations for the peripartum management of bipolar disorder. Areas covered: Three electronic databases, MEDLINE/PubMed, the Cochrane Library, and the National Guidelines Clearinghouse were searched using various combinations of the following terms: bipolar disorder, pregnancy, postpartum, peripartum, puerperal, antenatal, postnatal, and guidelines. All guidelines retrieved were published, revised, or reaffirmed during the period from November 2010-June 2016. Expert commentary: To date there are no exclusive guidelines for the peripartum management of bipolar disorder. Currently available guidelines do not provide sufficient guidance for clinicians to deliver optimal care to women before, during, and after pregnancy. The guidelines reflect the paucity of available literature on the peripartum management of bipolar disorder. Further research is urgently needed to strengthen the evidence supporting the guidelines recommendations.

The treatment of epilepsy in pregnancy: The neurodevelopmental risks associated with exposure to antiepileptic drugs

A number of antiepileptic drugs (AEDs) have been confirmed as teratogens due to their association with an increased malformation rate. The majority of research to date does not find an association between prenatal exposure to monotherapy carbamazepine, lamotrigine or phenytoin and neurodevelopmental outcome in comparison to control children and noted higher abilities in comparison to children exposed to valproate; but further work is needed before conclusions can be drawn. Data for levetiracetam was limited to one study, as was the evidence for topiramate. Sodium valproate exposure appeared to carry a dose dependent risk to the developing brain, with evidence of reduced levels of IQ, poorer verbal abilities and increased rate of autistic spectrum disorder both in comparison to control children and children exposed to other AEDs. The severity of the neurodevelopmental deficits associated with prenatal exposure to valproate highlight the critical need to consider neurodevelopmental outcomes as a central aspect of teratological research.

Children (10-12 years age) of women with epilepsy have lower intelligence, attention and memory: Observations from a prospective cohort case control study

OBJECTIVE

To compare the cognitive outcome of children of women with epilepsy (CWE) with matched controls (CWO).

METHODS

CWE (10-12 years) under follow up in Kerala Registry of Epilepsy and Pregnancy (n=190) were evaluated with WISC-IV, Trail Making Test (TMT), Rey Auditory Verbal Learning Test (RAVLT) and compared with age and sex matched children of women without epilepsy - CWO (n=149) drawn from schools in the same region. The dosage was expressed as prescribed daily dose/daily-defined dose (PDD/DDD) ratio in order to make comparisons.

RESULTS

The Full Scale IQ of CWE (77.9 ± 14.6) was 8.5 points lower than that of CWO (86.4 ± 13.4), which was statistically significant (p=0.001). They performed lower on TMT Part A & B and RAVLT. The FSIQ mean ± SD; PDD/DDD ratio and number of monotherapy exposure for different anti-epileptic drugs were phenobarbital: (74.5 ± 14; 1.1 ± 0.8; 22), valproate: (82.8 ± 12.4; 0.3 ± 0.1; 36), carbamazepine: (82.2 ± 13.9; 0.6 ± 0.3; 41), phenytoin: (82.6 ± 13.5; 0.8±0.3; 11). The FSIQ for those exposed to phenobarbital was significantly (p=0.01) lower than others. The significant predictors of FSIQ differed at lower and higher ends of its spectrum. These predictors were low body mass index and low maternal education for FSIQ<80 and low maternal education, low maternal IQ and high anti-epileptic drug dosage for FSIQ<86. High anti-epileptic drug dosage, low maternal IQ, and low paternal education were the predictors for FSIQ<92.

SIGNIFICANCE

The IQ, attention and memory were significantly lower for 10-12 year old CWE when compared to CWO. The important predictors of low FSIQ were antiepileptic drug dosage, maternal IQ, and parental education.

Valproate Prescribing in Women of Childbearing Age: An Audit of Clinical Practice

Background. Evidence is accruing regarding the risks of valproate exposure in women of childbearing age. Recommendations have recently been made for a higher standard of prenatal counselling and prescribing practice in respect of valproate use in this patient group. Aim and Method. A reaudit was carried out to review the standard of clinical discussion around teratogenic risk and pregnancy planning offered to women of child-bearing age prescribed valproate. Case notes and prescription charts of women 45 years old or less were examined and compared with the results of a previous audit in 2005. Results. The use of valproate was increased overall by 64% and there was an 18% increase in off-label valproate use. The rate of clinical discussion carried out during commencement declined from 70% to 35% and at annual review from 50% to 22%. There was less clinical discussion in outpatients and in older patients. More than 40% of doctors surveyed were not confident about giving information to women. Clinical Implication. There is a need for a multidisciplinary approach and action at Healthcare Trust level, to increase awareness and reduce risks associated with valproate prescribing in childbearing women.

Treatment for epilepsy in pregnancy: neurodevelopmental outcomes in the child

BACKGROUND

Accumulating evidence suggests an association between prenatal exposure to antiepileptic drugs (AEDs) and increased risk of both physical anomalies and neurodevelopmental impairment. Neurodevelopmental impairment is characterised by either a specific deficit or a constellation of deficits across cognitive, motor and social skills and can be transient or continuous into adulthood. It is of paramount importance that these potential risks are identified, minimised and communicated clearly to women with epilepsy.

OBJECTIVES

To assess the effects of prenatal exposure to commonly prescribed AEDs on neurodevelopmental outcomes in the child and to assess the methodological quality of the evidence.

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialized Register (May 2014), Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2014, Issue 4), MEDLINE (via Ovid) (1946 to May 2014), EMBASE (May 2014), Pharmline (May 2014) and Reprotox (May 2014). No language restrictions were imposed. Conference abstracts from the last five years were reviewed along with reference lists from the included studies.

SELECTION CRITERIA

Prospective cohort controlled studies, cohort studies set within pregnancy registers and randomised controlled trials were selected for inclusion. Participants were women with epilepsy taking AED treatment; the two control groups were women without epilepsy and women with epilepsy who were not taking AEDs during pregnancy.

DATA COLLECTION AND ANALYSIS

Three authors (RB, JW and JG) independently selected studies for inclusion. Data extraction and risk of bias assessments were completed by five authors (RB, JW, AS, NA, AJM). The primary outcome was global cognitive functioning. Secondary outcomes included deficits in specific cognitive domains or prevalence of neurodevelopmental disorders. Due to substantial variation in study design and outcome reporting only limited data synthesis was possible.

MAIN RESULTS

Twenty-two prospective cohort studies were included and six registry based studies. Study quality varied. More recent studies tended to be larger and to report individual AED outcomes from blinded assessments, which indicate improved methodological quality.The developmental quotient (DQ) was lower in children exposed to carbamazepine (CBZ) (n = 50) than in children born to women without epilepsy (n = 79); mean difference (MD) of -5.58 (95% confidence interval (CI) -10.83 to -0.34, P = 0.04). The DQ of children exposed to CBZ (n = 163) was also lower compared to children of women with untreated epilepsy (n = 58) (MD -7.22, 95% CI -12.76 to - 1.67, P = 0.01). Further analysis using a random-effects model indicated that these results were due to variability within the studies and that there was no significant association with CBZ. The intelligence quotient (IQ) of older children exposed to CBZ (n = 150) was not lower than that of children born to women without epilepsy (n = 552) (MD -0.03, 95% CI -3.08 to 3.01, P = 0.98). Similarly, children exposed to CBZ (n = 163) were not poorer in terms of IQ in comparison to the children of women with untreated epilepsy (n = 87) (MD 1.84, 95% CI -2.13 to 5.80, P = 0.36). The DQ in children exposed to sodium valproate (VPA) (n = 123) was lower than the DQ in children of women with untreated epilepsy (n = 58) (MD -8.72, 95% -14.31 to -3.14, P = 0.002). The IQ of children exposed to VPA (n = 76) was lower than for children born to women without epilepsy (n = 552) (MD -8.94, 95% CI -11.96 to -5.92, P < 0.00001). Children exposed to VPA (n = 89) also had lower IQ than children born to women with untreated epilepsy (n = 87) (MD -8.17, 95% CI -12.80 to -3.55, P = 0.0005).In terms of drug comparisons, in younger children there was no significant difference in the DQ of children exposed to CBZ (n = 210) versus VPA (n=160) (MD 4.16, 95% CI -0.21 to 8.54, P = 0.06). However, the IQ of children exposed to VPA (n = 112) was significantly lower than for those exposed to CBZ (n = 191) (MD 8.69, 95% CI 5.51 to 11.87, P < 0.00001). The IQ of children exposed to CBZ (n = 78) versus lamotrigine (LTG) (n = 84) was not significantly different (MD -1.62, 95% CI -5.44 to 2.21, P = 0.41). There was no significant difference in the DQ of children exposed to CBZ (n = 172) versus phenytoin (PHT) (n = 87) (MD 3.02, 95% CI -2.41 to 8.46, P = 0.28). The IQ abilities of children exposed to CBZ (n = 75) were not different from the abilities of children exposed to PHT (n = 45) (MD -3.30, 95% CI -7.91 to 1.30, P = 0.16). IQ was significantly lower for children exposed to VPA (n = 74) versus LTG (n = 84) (MD -10.80, 95% CI -14.42 to -7.17, P < 0.00001). DQ was higher in children exposed to PHT (n = 80) versus VPA (n = 108) (MD 7.04, 95% CI 0.44 to 13.65, P = 0.04). Similarly IQ was higher in children exposed to PHT (n = 45) versus VPA (n = 61) (MD 9.25, 95% CI 4.78 to 13.72, P < 0.0001). A dose effect for VPA was reported in six studies, with higher doses (800 to 1000 mg daily or above) associated with a poorer cognitive outcome in the child. We identified no convincing evidence of a dose effect for CBZ, PHT or LTG. Studies not included in the meta-analysis were reported narratively, the majority of which supported the findings of the meta-analyses.

AUTHORS' CONCLUSIONS

The most important finding is the reduction in IQ in the VPA exposed group, which are sufficient to affect education and occupational outcomes in later life. However, for some women VPA is the most effective drug at controlling seizures. Informed treatment decisions require detailed counselling about these risks at treatment initiation and at pre-conceptual counselling. We have insufficient data about newer AEDs, some of which are commonly prescribed, and further research is required. Most women with epilepsy should continue their medication during pregnancy as uncontrolled seizures also carries a maternal risk.

Risks of neurobehavioral teratogenicity associated with prenatal exposure to valproate monotherapy: a systematic review with regulatory repercussions

Beyond its formal indications (epilepsy, bipolar disorder, and migraine), valproate sodium (VPA) is widely used in a number of other clinical conditions. Recently, however, the U.S. Food and Drug Administration (FDA) issued a warning regarding a decrease in IQ scores in children prenatally exposed to the drug. For patients with migraine, the pregnancy labeling of VPA will be changed from Category "D" to "X." VPA products will remain in pregnancy category "D" for treating epilepsy and manic episodes associated with bipolar disorder. Thus, this article aims to assess (through a computerized Medline/PubMed search) the neurobehavioral teratogenicity of valproate monotherapy, in order to evaluate alternative regulatory decisions. Reviewed information suggests a detrimental impact of antenatal valproate exposure on the global child neurodevelopment. Affected areas include not just reduced IQ scores, but also behavioral problems and a potential increase in the risk for a future diagnosis of attention-deficit/hyperactivity disorder. An increased risk of developing autism-spectrum disorders has also been reported. Thus, in my opinion, VPA should be assigned definitively to the Category "X," independent of any considerations about its clinical indications, and should be strictly avoided during pregnancy, due to the demonstrated risk of both neurobehavioral and neurocognitive teratogenicity.

Preschool behavioral problems in children prenatally exposed to antiepileptic drugs - a follow-up study

We studied the association between maternal epilepsy, antiepileptic drug (AED) treatment, and behavioral problems in preschool children. In the Danish National Birth Cohort, we identified 4- to 5-year-old children whose mothers had epilepsy and received AED treatment (n=133) or not (n=304) during pregnancy and compared them with randomly selected children whose mothers did not have epilepsy (n=1193). The children's behavioral problems were assessed by the use of the Strengths and Difficulties Questionnaire (SDQ). Children prenatally exposed to AEDs more often had an abnormal total SDQ score as compared with children of women without epilepsy (odds ratio (OR)=4.8 (95% CI: 1.9-12.1)) and as compared with children of women with epilepsy who were not treated with AEDs during their pregnancy (OR=4.0 (95% CI: 1.3-12.8)). In conclusion, prenatal AED exposure may increase the risk of behavioral problems in preschool children even after adjustments for potential confounders and maternal epilepsy.

Psychopharmacological treatment of mood and anxiety disorders during pregnancy

Many women with psychiatric disorders want to become mothers and only a minority seek advise prior to becoming pregnant. In those women, in whom pregnancy can be planned, the decision, if a medication is required for stabilisation and which one to choose if this is the case, is easier to make than in women in whom pregnancy occurs unplanned. The physician has to weigh the risk that a relapse of the psychiatric disorder during pregnancy poses to the foetus against the reproductive risk of psychotropic drugs. This presentation is intended to assist in understanding the general principles of pharmacotherapy during pregnancy as well as the morphological, perinatal and neurobehavioural toxicity of antidepressants, antipsychotics, benzodiazepines and mood stabilisers.

Antiepileptic drugs and pregnancy outcomes

The treatment of epilepsy in women of reproductive age remains a clinical challenge. While most women with epilepsy (WWE) require anticonvulsant drugs for adequate control of their seizures, the teratogenicity associated with some antiepileptic drugs (AEDs) is a risk that needs to be carefully addressed. Antiepileptic medications are also used to treat an ever broadening range of medical conditions such as bipolar disorder, migraine prophylaxis, cancer, and neuropathic pain. Despite the fact that the majority of pregnancies of WWE who are receiving pharmacological treatment are normal, studies have demonstrated that the risk of having a pregnancy complicated by a major congenital malformation is doubled when comparing the risk of untreated pregnancies. Furthermore, when AEDs are used in polytherapy regimens, the risk is tripled, especially when valproic acid (VPA) is included. However, it should be noted that the risks are specific for each anticonvulsant drug. Some investigations have suggested that the risk of teratogenicity is increased in a dose-dependent manner. More recent studies have reported that in utero exposure to AEDs can have detrimental effects on the cognitive functions and language skills in later stages of life. In fact, the FDA just issued a safety announcement on the impact of VPA on cognition (Safety Announcement 6-30-2011). The purpose of this document is to review the most commonly used compounds in the treatment of WWE, and to provide information on the latest experimental and human epidemiological studies of the effects of AEDs in the exposed embryos.

Neurobehavioral consequences of prenatal antiepileptic drug exposure

Despite elevated rates of birth defects associated with prenatal antiepileptic drug exposure, pharmacotherapy is typically continued throughout pregnancy because of the risks posed to mother and child by recurrent seizures. Emerging data suggest that prenatal exposure to valproate or polytherapy may also be associated with increased risk of cognitive impairment. However, our understanding of the longer-term sequelae of prenatal antiepileptic drug exposure remains incomplete. Improved understanding of the neurobehavioral consequences of prenatal antiepileptic drug exposure is essential to ensure accurate information is available for women with epilepsy planning a pregnancy, and to achieve optimal outcomes for mothers and children.

Child development following in utero exposure: levetiracetam vs sodium valproate

OBJECTIVE

Children born to women with epilepsy (WWE), exposed in utero to levetiracetam (LEV, n = 51), were assessed for early cognitive development and compared to children exposed to sodium valproate in utero (VPA, n = 44) and a group of children representative of the general population (n = 97).

METHODS

Children were recruited prospectively from 2 cohorts in the United Kingdom and assessed using the Griffiths Mental Development Scale (1996), aged <24 months. Information regarding maternal demographics were collected and controlled for. This is an observational study with researchers not involved in the clinical management of the WWE.

RESULTS

On overall developmental ability, children exposed to LEV obtained higher developmental scores when compared to children exposed to VPA (p < 0.001). When compared, children exposed to LEV did not differ from control children (p = 0.62) on overall development. Eight percent of children exposed to LEV in utero fell within the below average range (DQ score of <84), compared with 40% of children exposed to VPA. After controlling for maternal epilepsy and demographic factors using linear regression analysis, exposure to LEV in utero was not associated with outcome (p = 0.67). Conversely, when compared with VPA exposure, LEV exposure was associated with higher scores for the overall developmental quotient (p < 0.001).

CONCLUSION

Children exposed to LEV in utero are not at an increased risk of delayed early cognitive development under the age of 24 months. LEV may therefore be a preferable drug choice, where appropriate, for WWE prior to and of childbearing age.

The Australian brain and cognition and antiepileptic drugs study: IQ in school-aged children exposed to sodium valproate and polytherapy

Prenatal exposure to sodium valproate (VPA) and polytherapy has been linked with increased risk of birth defects and cognitive impairment in young children. We evaluated the cognitive impact of prenatal exposure to VPA and polytherapy in school-aged children. Fifty-seven children exposed to VPA (n = 23), polytherapy with VPA (n = 15), or polytherapy without VPA (n = 19) were assessed using the Wechsler Intelligence Scale for Children--Fourth Edition. Information on maternal epilepsy, pregnancy, and medical history was obtained prospectively through the Australian Pregnancy Register for Women with Epilepsy and Allied Disorders. All groups had elevated frequencies of Extremely Low (<70) or Borderline (70-79) Full-Scale IQ (15.8-40.0%). Verbal Comprehension and Working Memory scores in all groups fell significantly below the standardized test mean, while Perceptual Reasoning and Processing Speed scores were relatively intact. Multivariate analysis of covariance analysis revealed significant main effects of VPA on Verbal Comprehension and Working Memory, and of polytherapy on Verbal Comprehension and Processing Speed. Our results suggest that VPA has a dose-dependent negative impact on verbal intellectual abilities, and may also affect working memory. The possibility that inclusion of VPA in many polytherapy regimens may underlie reduced mean scores of polytherapy-exposed children is discussed.

Teratogenic effects of antiepileptic drugs

Many antiepileptic drugs (AEDs) have therapeutic applications that extend beyond epilepsy to include neuropathic pain, migraine headaches and psychiatric disorders. The risk of some AEDs has been clearly established, but for newer drugs, small sample sizes and polytherapy exposures preclude a conclusive determination of their teratogenic potential. Most women with epilepsy will require AED therapy throughout their entire pregnancy to control seizures; the vast majority of pregnancies in women with epilepsy have positive outcomes. A conservative estimate suggests that AED monotherapy doubles, and polytherapy triples, the risk for major congenital malformations. Furthermore, while evidence is still accruing, recent investigations suggest that exposure to select AEDs results in altered cognitive function later in development. There is no evidence to suggest that additional folic acid supplementation ameliorates the increased risk of congenital malformations conferred by in utero AED exposure.

The management of epilepsy in pregnancy

While most women with epilepsy can expect a normal pregnancy outcome, epilepsy remains a significant contributor to both maternal and perinatal morbidity. Pre-pregnancy planning must address reliable contraception and optimisation of antiepileptic drug (AED) regimens to minimise teratogenic risk while maintaining seizure control. The most recent data from the AED registries regarding malformations is presented in this review, as is the limited data on the newer AEDs and studies linking neurocognitive outcomes to AED exposure. During pregnancy, important considerations include; therapeutic drug monitoring, surveillance for obstetric complications and vigilance for seizures during the intrapartum and postpartum period.

Cognitive abilities and behaviour of children exposed to antiepileptic drugs in utero

PURPOSE OF REVIEW

The last two decades have witnessed a growing concern over the treatment of epilepsy in women of childbearing age, with an increased risk of major congenital malformations and possible cognitive difficulties associated with certain antiepileptic drugs. The aim here is to review the literature regarding the possible cognitive and behavioural impact of exposure to antiepileptic drugs in utero.

RECENT FINDINGS

Recent evidence from large prospective cohorts indicates that there is a longer term risk to the cognitive and behavioural development of the child exposed in utero to sodium valproate. Information on other antiepileptic agents is conflicting or nonexistent and more research in this area is urgently required.

SUMMARY

Despite the methodological shortfalls of some of the research in this area, there is an accumulation of evidence highlighting an increased risk for cognitive and behavioural difficulties in children exposed to sodium valproate in utero. Although less certain, there may also be risks associated with phenobarbital and phenytoin exposure. Information regarding these risks should be communicated to the potential mother who has epilepsy.

The aspects and mechanisms of cognitive alterations in epilepsy: the role of antiepileptic medications

Epilepsy is a major health problem. Several studies suggest a significant influence of epilepsy and its treatment on dynamic and functional properties of brain activity. Epilepsy can adversely affect mental development, cognition, and behavior. Epileptic patients may experience reduced intelligence, attention, and problems in memory, language, and frontal executive functions. Neuropsychological, functional, and quantitative neuroimaging studies revealed that epilepsy affect the brain as a whole. Mechanisms of epilepsy-related cognitive dysfunction are poorly delineated. Cognitive deficits with epilepsy may be transient, persistent, or progressive. Transient disruption of cognitive encoding processes may occur with paroxysmal focal or generalized epileptic discharges, whereas epileptogenesis-related neuronal plasticity, reorganization, sprouting, and impairment of cellular metabolism are fundamental determinants for progressive cognitive deterioration. Also antiepileptic drugs (AEDs) have differential, reversible, and sometimes cumulative cognitive adverse consequences. AEDs not only reduce neuronal irritability but also may impair neuronal excitability, neurotransmitter release, enzymes, and factors critical for information processing and memory. The present article serves as an overview of recent studies in adult and childhood epilepsy literatures present in PubMed that highlighted cognitive evaluation in epilepsy field (publications till 2008 were checked). We also checked the reference lists of the retrieved studies for additional reports of relevant studies, in addition to our experience in this field. Our search revealed that although the aspects of cognitive dysfunction, risk factors, and consequences have been explored in many studies; however, the mechanisms of contribution of epilepsy-related variables, including AEDs, to patients' cognition are largely unexplored. In this review, we discussed the differential effect of AEDs in mature and immature brains and the known mechanisms underlying epilepsy and AEDs adverse effects on cognition. The nature, timing, course, and mechanisms of cognitive alteration with epilepsy and its medications are of considerable clinical and research implications.

Dose-dependent memory effects and cerebral volume changes after in utero exposure to valproate in the rat

PURPOSE

Recent clinical studies raised concern of a cognitive teratogenicity of the major antiepileptic drug valproate. To investigate possible cerebral correlates, we established a forced self-application schedule by diluting valproate in the drinking water of pregnant Wistar rats.

METHODS

After application of medium (MD) and high doses (HDs) with mean daily intakes of about 470 and 720 mg/kg during the entire pregnancy, we analyzed effects on offspring performance in a series of behavioral paradigms as well as brain volumetric changes by magnetic resonance imaging (MRI).

RESULTS

While high dosages with peak serum concentrations slightly above 100 microg/ml induced early decrements in general activity and deficits in learning and memory, medium dosages led to improved watermaze performance in 30-day-old rats. MRI analyses indicated increased hippocampal volumes in the MD condition, whereas in the HD condition significantly decreased cortical and brainstem volumes were registered. Cortical volume reduction was correlated with spatial acuity in the watermaze.

CONCLUSIONS

The results indicate that effects of valproate in utero on offspring cognitive capabilities might depend on total drug load differentially affecting cerebral development during adolescence in the rat.