Genetic variant interpretation for the neurologist - A pragmatic approach in the next-generation sequencing era in childhood epilepsy.

Genetic advances over the past decade have enhanced our understanding of the genetic landscape of childhood epilepsy. However a major challenge for clinicians ha been understanding the rationale and systematic approach towards interpretation of the clinical significance of variant(s) detected in their patients. As the clinical paradigm evolves from gene panels to whole exome or whole genome testing including rapid genome sequencing, the number of patients tested and variants identified per patient will only increase. Each step in the process of variant interpretation has limitations and there is no single criterion which enables the clinician to draw reliable conclusions on a causal relationship between the variant and disease without robust clinical phenotyping. Although many automated online analysis software tools are available, these carry a risk of misinterpretation. This guideline provides a pragmatic, real-world approach to variant interpretation for the child neurologist. The focus will be on ascertaining aspects such as variant frequency, subtype, inheritance pattern, structural and functional consequence with regard to genotype-phenotype correlations, while refraining from mere interpretation of the classification provided in a genetic test report. It will not replace the expert advice of colleagues in clinical genetics, however as genomic investigations become a first-line test for epilepsy, it is vital that neurologists and epileptologists are equipped to navigate this landscape.

Metabolic causes of pediatric developmental & epileptic encephalopathies (DEE)- genetic variant analysis in a south Indian cohort.

PURPOSE: Drug-resistant epilepsy is seen in patients with inborn errors of metabolism and metabolic dysfunction in neurons is crucial to brain disorders associated with psychomotor impairment. Diagnostic rates of metabolic causes of developmental and epileptic encephalopathy (DEE) using next generation sequencing have been rarely studied in literature. METHODS: A prospective hospital study was carried out in 384 children with DEE, who underwent genetic testing. Metabolic disorders were evaluated with biochemical blood/urine assays and when required CSF estimations performed. RESULTS: A total of 154 pathogenic/likely pathogenic variants in 384 children were identified. Out of 384 children, 89 were clinically suspected to have probable or possible metabolic disorders. Pathogenic/likely pathogenic variants in metabolic genes were identified in 39 out of 89 (43.8 %) and promising VUS in 28 (31.4 %). These included variants for progressive myoclonus epilepsies (21; 53.8 %), DEE with focal/multifocal seizures (8; 20.5 %), generalized epilepsy (5;12.8 %), early myoclonic encephalopathy (2; 5.1 %), LGS (1; 2.6 %) and West syndrome (2; 5.1 %). CONCLUSION: Our cohort demonstrates for the first time from the Indian subcontinent that identification of metabolic variants can guide investigations and has therapeutic implications in patients with variable DEE phenotypes. A high utility is noted with regard to diagnosis and prognostication, given the low yield of available biochemical tests, indicating cost-effectiveness of this approach.

Impact of variant subtype on electro-clinical phenotype of Dravet syndrome- a South Indian cohort study.

OBJECTIVE: We aimed to compare the electroclinical correlates of truncating and missense variants of SCN1A variants in children with Dravet syndrome (DS) and to determine phenotypic features in relation to variants identified and seizure outcomes. METHODS: A single center prospective study was carried out on a South Indian cohort. Patients below 18 years of age who met the clinical criteria for DS who had undergone genetic testing and completed a minimum of one year follow up were included. We compared the differences in clinical profile, seizure outcome, developmental characteristics and anti-seizure medication (ASM) responsiveness profiles between patients with missense and truncating variants. RESULTS: Out of a total of 3967 children with drug-resistant epilepsy during the period 2015-2021, 49 patients who fulfilled the inclusion criteria were studied. Thirty-seven had positive genetic tests, out of which 29 were SCN1A variants and 9 were other novel variants. The proportion of missense (14; 48.3%) and truncating SCN1A variants (15; 51.7%) was similar. A significant trend for developing multiple seizure types was noted among children with truncating variants (p = 0.035) and seizure freedom was more likely among children with missense variants (p = 0.042). All patients with truncating variants had ASM resistant epilepsy (p = 0.020). Developmental outcomes did not differ between the variant subtypes. CONCLUSION: Our results show that children harbouring missense variants demonstrated a significantly lower propensity for multiple seizure subtypes and a higher proportion with seizure freedom. However developmental implications appear to be independent of variant subtype.

KCTD7-related progressive myoclonic epilepsy: Report of 42 cases and review of literature.

OBJECTIVE: KCTD7-related progressive myoclonic epilepsy (PME) is a rare autosomal-recessive disorder. This study aimed to describe the clinical details and genetic variants in a large international cohort. METHODS: Families with molecularly confirmed diagnoses of KCTD7-related PME were identified through international collaboration. Furthermore, a systematic review was done to identify previously reported cases. Salient demographic, epilepsy, treatment, genetic testing, electroencephalographic (EEG), and imaging-related variables were collected and summarized. RESULTS: Forty-two patients (36 families) were included. The median age at first seizure was 14 months (interquartile range = 11.75-22.5). Myoclonic seizures were frequently the first seizure type noted (n = 18, 43.9%). EEG and brain magnetic resonance imaging findings were variable. Many patients exhibited delayed development with subsequent progressive regression (n = 16, 38.1%). Twenty-one cases with genetic testing available (55%) had previously reported variants in KCTD7, and 17 cases (45%) had novel variants in KCTD7 gene. Six patients died in the cohort (age range = 1.5-21 years). The systematic review identified 23 eligible studies and further identified 59 previously reported cases of KCTD7-related disorders from the literature. The phenotype for the majority of the reported cases was consistent with a PME (n = 52, 88%). Other reported phenotypes in the literature included opsoclonus myoclonus ataxia syndrome (n = 2), myoclonus dystonia (n = 2), and neuronal ceroid lipofuscinosis (n = 3). Eight published cases died over time (14%, age range = 3-18 years). SIGNIFICANCE: This study cohort and systematic review consolidated the phenotypic spectrum and natural history of KCTD7-related disorders. Early onset drug-resistant epilepsy, relentless neuroregression, and severe neurological sequalae were common. Better understanding of the natural history may help future clinical trials.

Arginase deficiency-An unheralded cause of developmental epileptic encephalopathy.

Arginase deficiency, which leads to hyperargininaemia is a rare urea cycle disorder caused by a mutation in the ARG1 gene. It is an under-recognized cause of pediatric developmental epileptic encephalopathy, with the key coexistent clinical features being developmental delay or regression and spasticity. Detection of ARG1 gene mutation on genetic testing is the confirmatory diagnostic test. However, elevated levels of plasma arginine and low plasma arginase level can be considered as biochemical markers for diagnosis. We present two cases of arginase deficiency with genetically confirmed ARG1 mutation in one and biochemical confirmation in both. As the spectrum of epilepsy in arginase deficiency has been less explored, we attempted to elucidate the novel electroclinical features and syndromic presentations in these patients. Informed consent was obtained from families of patients. Electroclinical diagnosis was consistent with Lennox Gastaut syndrome (LGS) in the first patient while the second patient had refractory atonic seizures with electrophysiological features consistent with developmental and epileptic encephalopathy. Though primary hyperammonaemia is not a consistent feature, secondary hyperammonaemia in the setting of infectious triggers and drugs like valproate (valproate sensitivity) has been well described as also observed in our patient. In the absence of an overt antecedent in a child with spasticity and seizure disorder, with a progressive course consistent with a developmental epileptic encephalopathy, arginase deficiency merits consideration. Diagnosis often has important therapeutic implications with respect to dietary management and choice of the appropriate antiseizure medications.

C12orf57 pathogenic variants: a unique cause of developmental encephalopathy in a south Indian child.

Open reading frame variants which lack stop codons such as C12orf57 variants are known to cause Temtamy syndrome, an extremely rare disorder characterized by intellectual disability, seizures, facial dysmorphism and agenesis of corpus callosum. C12orf57 was initially reported to be required for human corpus callosum development. We report the first child who is of Indian origin with developmental and epileptic encephalopathy (DEE) with a unique phenotypic evolution as focal onset reflex seizures. We performed whole exome sequencing of genomic DNA isolated from peripheral blood samples of proband and his parents. Two pathogenic compound heterozygous variants, a start loss variant (Chr12:7053285:c.1A>G) and a premature stop gain variant (Chr12:7053327:c.43C>T), involving the C12orf57 gene were identified in the proband. Our case report which details genotyping in this rare syndromic developmental encephalopathy, with no prior cases reported from India, expands the ethnic spectrum of patients.

Language, intelligence, and educational outcomes of adolescents with antenatal exposure to antiseizure medications: Prospective data from the Kerala Registry of epilepsy and pregnancy.

OBJECTIVE: In a prospective cohort of children (13-21 years) of women with epilepsy (CWWE), we compared those exposed to antiseizure medications (ASM) in utero to those without exposure to ASM regarding their language proficiency and intelligence. We also compared their educational performance with state-wide averages. METHODS: Research staff blinded to the ASM exposure of CWWE administered the Clinical Evaluation of Language Fundamentals IV and the Wechsler Intelligence Scale for Children IV to test their language proficiency and intelligence. We assessed their educational performance with a questionnaire. CWWE without antenatal exposure to ASM served as comparators for language and intelligence tests. The educational performance of CWWE (regardless of ASM exposure) was compared with the state-wide averages published by the government. RESULTS: In total, 446 children (mean age 16.5 ± 2.2 years; 236 girls) participated in the study. Their ASM exposure involved monotherapy for 272 (61%), polytherapy for 133 (29.8%) and none for 41 (9.2%). The commonly used ASMs (mono & polytherapy) were carbamazepine (n = 192), valproate (n = 124), phenobarbitone (n = 95), and phenytoin (n = 73). The full-scale intelligence quotient of CWWE (n = 146) with antenatal exposure to ASM (89.2 ± 21.5) was significantly lower (p = 0.03) than that of CWWE (n = 11) unexposed to ASM (96.9 ± 8.8). The CELF core language scaled score for the exposed CWWE (n = 132) was significantly lower than that of unexposed children (n = 12; 99.2 ± 19.9). Compared with state-wide averages, CWWE (n = 386) had delayed initiation of education (2.6% vs. 0.1%), increased dropout rates (1% vs. 0.11%), increased usage of special assistance during examinations (4.4% vs. 0.1%) and a lower rate (19.9% vs. 37%) of enrolment in universities. CONCLUSION: The language and intelligence functions of CWWE with exposure to older ASMs were lower than those of unexposed CWWE. Compared to state-wide averages, a significantly higher proportion of CWWE had difficulties with education, and only a smaller proportion enrolled in higher education.

Differential impact of antenatal exposure to antiseizure medications on motor and mental development in infants of women with epilepsy.

OBJECTIVE: We aimed to determine a possible association between motor and mental development in infants of women with epilepsy and antenatal exposure to antiseizure medication (ASM). METHODS: Developmental paediatricians who were blinded to antenatal ASM exposure evaluated motor and mental development of infants (>12 months) using the Developmental Assessment Scale for Indian Infants (an Indian adaptation of the Bayley Scale of Infant Development). Motor (MODQ) and mental development quotients (MEDQ) were computed as ratios of respective developmental age to the chronological age of the child. We employed linear mixed models to study the relationship between antenatal exposure to ASM and the development quotients after adjustment for malformation status and age of the baby, maternal education and seizure type. RESULTS: We studied 1,357 infants with mean age of 15.3±4.0 months (71.2% of all eligible infants). Infants were classified as having monotherapy or polytherapy, or unexposed in 840, 407 and 110 participants, respectively. The MEDQ of the polytherapy (92.9±14.9) and monotherapy (96.9±13.9) groups was lower than that of unexposed infants (99.8 12.5). Similarly, the MODQ of polytherapy (91.1±19.3) and monotherapy (96.6±17.5) groups was lower than that of unexposed infants (97.6 16.6). The differences in adjusted mean MEDQ were -7.4 (-11.4 to -4.3, p=0.001), -9.6 (-11.3 to -6.0, p=0.001) and -6.4 (-9.2 to -3.7, p=0.001) for valproate monotherapy, polytherapy with valproate and polytherapy without valproate, respectively. The adjusted mean MODQ also showed a similar trend. Those exposed to levetiracetam (n=62) had higher or similar adjusted MODQ (110.4±14.3; p=0.001) and MEDQ (104.3±9.1; p=0.09), compared to unexposed infants. A dose-dependent decrease in developmental indicators was observed for valproate and phenobarbitone. SIGNIFICANCE: Antenatal exposure to ASM, especially valproate and phenobarbitone, adversely affects motor and mental development of exposed infants. Early developmental screening of high-risk infants is desirable.

Malformation risk of new anti-epileptic drugs in women with epilepsy; observational data from the Kerala registry of epilepsy and pregnancy (KREP).

OBJECTIVES: We aim to report the major congenital malformation (MCM) rates for new and old anti-epileptic drugs (AED) exposures during the first trimester of pregnancy in women with epilepsy (WWE). METHODS: We extracted relevant data on drug exposure and malformation rate from the records of a prospective observational registry (Kerala Registry of Epilepsy and Pregnancy) for all completed pregnancies between 1998 and 2019. A comprehensive and uniform criterion with detailed guideline was used for assessment of malformations. We employed generalised linear model to generate adjusted incidence rate ratios (aIRR) of MCM in AED exposed group as compared to AED unexposed group, after adjustment for age and educational status of mothers' and epilepsy classification. RESULTS: The unadjusted MCM rate was 6.2% for all the infants included in the study (148/2328); 4.7% for the unexposed group (16/340), and 6.6% for the exposed group (132/1988). The aIRR of MCM as compared to unexposed group was similar for all monotherapies; lamotrigine (0.50; 95% CI 0.07-3.68), levetiracetam (1.16; 0.43-3.11), oxcarbazepine (1.61; 0.62-4.21) valproate (1.71, 0.93-3.19), phenytoin (1.21, 0.51-2.90), carbamazepine (0.99, 0.54-1.82), and phenobarbitone (1.20, 0.52-2.74). However, the point estimates suggest least risk with lamotrigine and highest risk with valproate. Polytherapy with high-dose valproate carried significantly higher risk of MCM as compared to the unexposed group (aIRR=4.12; 2.18-7.79, p<0.001). The aIRR of GTCS during pregnancy was 1.63 (95% CI 1.12-2.37, p = 0.011) for monotherapy with new AEDs (lamotrigine, levetiracetam or oxcarbazepine) as compared to old AEDs (phenobarbitone, phenytoin, carbamazepine, or valproate). CONCLUSION: The MCM risk was significantly higher for polytherapy with high dose valproate. It did not differ substantially between different AED monotherapies although point estimate was lowest with lamotrigine. Pregnant women on new AEDs report higher likelihood of GTCS than women on old AEDs during pregnancy.

Valproate usage in pregnancy: An audit from the Kerala Registry of Epilepsy and Pregnancy.

OBJECTIVE: This is an audit of the use of valproate (VPA) during pregnancy in women with epilepsy (WWE). METHODS: We identified all pregnancies exposed to VPA in the Kerala Registry of Epilepsy and Pregnancy between January 2010 and December 2019. Subjects' past usage of antiepileptic drugs (AEDs), seizure count before and during pregnancy, fetal outcome, and major congenital malformations (MCMs) were abstracted from the registry records. The presumed reason for usage of VPA was deducted from the clinical records. RESULTS: There were 221 pregnancies (17.75%) exposed to VPA (monotherapy, n = 149) during the audit period. The MCM rate for the completed pregnancies exposed to VPA was higher (n = 20, 10.36%) than that of VPA-unexposed pregnancies (n = 39, 4.96%). The relative risk for MCM with VPA exposure was 2.1 (95% confidence interval = 1.24-3.48, number needed to treat with VPA to result in MCM = 19). Reasons for using VPA during pregnancy (some women had more than one reason) were (1) VPA was the first AED prescribed and was effective (68, 29.06%), (2) other AEDs were ineffective (128, 54.70%), and (3) other AEDs were discontinued due to adverse effects (17, 7.28%). Other reasons (21, 8.97%) were (1) VPA was selected after the epilepsy classification was revised (3, 1.28%), (2) other AEDs were expensive (2, .85%), and (3) patient switched to VPA from other AEDs for unspecified reason (16, 6.83%). VPA was discontinued during pregnancy for 6 (2.71%) persons. Less than 10% of women were tried on lamotrigine or levetiracetam before switching to VPA. SIGNIFICANCE: Nine MCMs per thousand pregnancies can be avoided if VPA is not used in WWE. Safe and effective AEDs as alternatives to VPA are the need of the hour. Professional bodies and regulatory authorities need to implement updated guidelines on AED usage in girls and women.

Enduring language deficits in children of women with epilepsy and the potential role of intrauterine exposure to antiepileptic drugs.

OBJECTIVE: Exposure to certain intrauterine antiepileptic drugs (AEDs) can negatively influence the language skills and intelligence of young children. It remains unanswered whether these deficits are transient or persist as children grow up. This study aims to evaluate the language function of children of women with epilepsy (CWE) aged 9-13 years in comparison with their peers, and its relationship with intrauterine AED exposure. METHODS: We included 191 CWE in our study from the Kerala Registry of Epilepsy and Pregnancy. Children in the same age group (n = 144) and without maternal epilepsy or antenatal AED exposure served as controls. We used Clinical Examination for Language Function version IV to assess language in both groups. Relevant data related to maternal epilepsy and AED use were obtained from the registry records. RESULTS: The average Core Language Scaled Score (CLSS) was significantly lower in CWE as compared to controls (83.19 vs 90.18, P = .001). Similarly, the mean scaled scores in other language parameters were also significantly lower in CWE. In the multivariate analysis, compared to control children, the average CLSS in CWE was 4.5 units lower (95% confidence interval [CI] = -8.8 to -0.2, P = .04) with AED monotherapy exposure and 7.3 units lower with exposure to AED polytherapy (95% CI = -13.8 to -0.8, P = .03). Intrauterine exposure to phenobarbitone (n = 61) and valproate (n = 55) as either monotherapy or polytherapy showed a negative effect on CLSS in CWE as compared to control children. However, carbamazepine (n = 75) and phenytoin (n = 37) use was not associated with significant variation of CLSS. In head-to-head comparisons between AED monotherapies in CWE, phenobarbitone showed a negative effect on CLSS (-14.7, 95% CI = -23.1 to -6.4, P = .001) as compared to carbamazepine. SIGNIFICANCE: Intrauterine exposure to phenobarbitone and valproate impairs language development in CWE, with effects persisting into the second decade.

Women with drug-resistant epilepsy: Surgery or pregnancy first?

OBJECTIVE: We compared women with drug-resistant focal epilepsy who had undergone surgery (WWE-S) with those who were managed medically (WWE-M) for maternal and fetal outcomes of their pregnancies. METHODS: We classified all WWE-S who were enrolled in a prospective registry of epilepsy and pregnancy (1998-2015) as those who underwent the surgery before pregnancy (WWE-SF) or after pregnancy (WWE-PF). The comparator group (WWE-M) was twice that number of age-matched women with focal epilepsy in this registry. Their clinical profile, anti-epileptic drug (AED) use, and pregnancy outcomes were extracted from the records of the registry. RESULTS: The number of completed pregnancies with known outcome was 74 for WWE-S (67 WWE-SF and 7 WWE-PF) and 134 for WWE-M. Seizures increased during pregnancy for fewer WWE-SF than for WWE-M (14.9% vs 39.6%, P = .001). Compared to WWE-M, fewer WWE-SF had dose escalation during pregnancy (28.4% vs 14.9%, P = .025). Preterm deliveries were more frequent in WWE-SF than WWE-M (24.6% vs 12.2%, P = .029). The differences between the WWE-SF and WWE-M regarding the rates of fetal loss (10.4% vs 6.7%, P = .255), major congenital malformations (8.5% vs. 11.1%, P = .395), and development quotient at 1 year of age <85 (42.5% vs 42.3%, P = .569) were not statistically significant. Compared to WWE-PF, fewer WWE-SF had AED dose escalation (14.9% vs 85.7%, P = .001) or increase in seizures (14.9% vs 100%, P = .001) during pregnancy. WWE-SF had fewer infants with development quotient <85 (41.0% vs 100%, P = .005). SIGNIFICANCE: WWE-SF can expect better control of seizures and decreased AED burden during pregnancy than WWE with focal epilepsies managed with medicines only. WWE who undergo surgery for epilepsy before their pregnancies can expect fewer seizures and lower AED burden during pregnancy.

Do women with epilepsy benefit from epilepsy specific pre-conception care?

BACKGROUND: To determine how pre-conception care (PCC) influenced the outcome of epilepsy, pregnancy and malformation risk in women with epilepsy (WWE). METHODS: All primigravida in the Kerala registry of epilepsy and pregnancy (KREP) with the final outcome of pregnancy known who were enrolled prospectively in pre-conception stage (PCC group) or first trimester of pregnancy (PRG group) were included. The two groups were compared for fetal and maternal outcomes including seizure control and complications of pregnancy. RESULTS: There were 320 (30.4 %) in PCC group and 732 in PRG group. Both groups were comparable for epilepsy classification, maternal birth defects and family history of epilepsy but the PCC group had significantly higher education (48.9 %, p = .027) and employment (22.1 %, p < .001). They had higher usage of folate in pre-pregnancy month (87.5 %, p < .001) and first trimester (96.3 %, p < .001) than PRG group. Fewer women in the PCC group were off AEDs in first trimester (5 % vs 9.3 %, p = .018). Within monotherapy group, use of levetiracetam (10.8 %, p = .017), valproate (34 %, p = .002) in PCC group and carbamazepine (39.1 %, p = .04), phenobarbitone (13.3 %, p = .001) in PRG group was significantly high. More women in PCC group were seizure free during pregnancy (62.8 %, p = .005) than PRG group. Early fetal loss was better captured in PCC (90.6 %,p = .025) than in the PRG. There was no difference in malformation rate between PCC (7.2 %) and PRG groups (6.1 %, p = .3). CONCLUSION: PCC reduced the risk of seizures during pregnancy and improved the periconceptional use of folate but did not influence the fetal malformation risk.

Anti-epileptic drug and folic acid usage during pregnancy, seizure and malformation outcomes: Changes over two decades in the Kerala Registry of Epilepsy and Pregnancy.

BACKGROUND: This study was carried out to determine changes over time in use of folic acid, anti-epileptic drugs (AED), seizures during pregnancy and malformation rate over two decades in women with epilepsy enrolled in the Kerala registry of Epilepsy and Pregnancy (KREP). METHODS: All completed pregnancies with known outcome between 1998 and 2017 (n = 1962) were analyzed for the use of folic acid and AEDs in the first trimester, seizure count for the entire pregnancy and the presence of major congenital malformation (MCM). The results were presented for three epochs (1998-2004, 2005-2011 and 2012-2017). RESULTS: There was significant increase (p = .001) in the use of folic acid 5 mg/day or more in pre-pregnancy month (43.9 to 81 %) and first trimester (52.7 to 86.6 %). Occurrence of seizures during pregnancy had declined significantly (57.2 to 32.9 %, p = 0.001) over time. Those who were off AEDs during pregnancy declined from 17.4 to 8.5 % (p = .001). Newer AEDs - lamotrigine, levetiracetam, oxcarbazepine and topiramate) were increasingly preferred in the last seven years instead of older AEDs (phenobarbitone, phenytoin and clonazepam). There was no significant change in the use of carbamazepine or valproate. MCM rates did not show any significant change (7.5 to 7.3 %). CONCLUSION: Seizure control and high dose folic acid usage during pregnancy had improved over two decades. Despite the changes in the AED usage over time the MCM rates had remained unchanged probably due to continued use of valproate, increased use of topiramate and clobazam that are associated with higher MCM rates and lack of reduction in polytherapy.

Spontaneous fetal loss in women with epilepsy: prospective data from pregnancy registry in India.

OBJECTIVE: To ascertain the risk of spontaneous fetal loss (SPFL) in women with epilepsy (WWE) on antiepileptic drugs (AED), and explore the association between specific AED usage and risk of SPFL. METHODS: We identified all SPFL (including stillbirths) among pregnancies registered at Kerala Registry for Epilepsy and Pregnancy between 1998 and 2015. Rates of SPFL were compared between the AED exposed and unexposed groups. RESULTS: There were 139 SPFL out of 1987 eligible pregnancies. The AED exposed had excess SPFL (7.4%, 134 out of 1809, Odds Ratio [OR] 2.77, 95% Confidence Interval [CI] 1.17-6.39) than AED unexposed (2.8%, 5 out of 178). The adjusted OR (95% CI) for SPFL for monotherapies with levetiracetam, phenobarbitone and clobazam were comparable to unexposed, while it was significantly higher for topiramate (OR 38.86, CI 5.02-301.19), lamotrigine (OR 13.33, CI 1.41-125.78), oxcarbazepine (OR 7.53, CI 1.54-36.89), valproate (OR 6.92, CI 1.70-28.18), phenytoin (OR 5.82, CI 1.43-23.73) and carbamazepine (OR 3.53, CI 1.15-10.90). With reference to levetiracetam, only topiramate had significantly higher SPFL (OR 11.14, CI 1.56-79.55). CONCLUSION: SPFL risk is increased in pregnancies with AED exposure, being least with levetiracetam and highest with topiramate.

Do Anti-Epileptic Drug modifications after first trimester of pregnancy influence fetal malformation or cognitive outcome?

OBJECTIVE: The management of Women With Epilepsy (WWE) in pregnancy is a challenge that demands balancing the risks of Major Congenital Malformation (MCM) on one hand with adequate seizure control on the other. While most studies have analysed the risks of Anti-Epileptic Drugs (AED) exposure in the first trimester, AED changes during the second and third trimester and their effects on fetal outcome has not been studied adequately. MATERIALS AND METHODS: Data of WWE who were prospectively followed up and completed pregnancy with live birth under the Kerala registry of epilepsy and pregnancy (KREP) between 1998 and 2014 were analysed. The AED addition, dose escalation, unchanged continuation, dose reduction or stoppage during the second or third trimester in comparison to the first trimester was tabulated for each drug. The outcome measures evaluated were malformation status and Developmental Quotient (DQ) at one year as extracted from the clinical records of the registry. RESULTS: The first trimester AED exposure was nil for 231, monotherapy for 925 and polytherapy for 391 WWE. WWE on monotherapy in first trimester were more likely to remain on the same number of AEDs in second or third trimester than those who were on polytherapy (OR 3.1, 95% CI 2.2 - 4.46). AED naïve women had a higher likelihood (OR 16.7; 95% CI 10.9-25.8) of being started on AED than women on monotherapy being switched to polytherapy. At least one AED was reduced or stopped during second or third trimester more often in women on polytherapy (15.1%) than in women on monotherapy (3.7%) (OR 4.7; 95% CI 2.9-7.2). Malformation rates for the infants of women whose AED dosage was increased or added were not significantly different from those of others. There was no statistically significant change in DQ with increase in dose or addition of drugs in the second or third trimester. CONCLUSION: AEDs were reduced in a significant proportion of patients on polytherapy while more than a third of women who were not on AEDs in the first trimester were subsequently started on AEDs. Increase in dose or addition of AEDs after the first trimester is unlikely to influence malformation outcome but the potential adverse effect on the DQ needs to be explored on a larger set of data.

Teratogenicity of antiepileptic dual therapy: Dose-dependent, drug-specific, or both?

OBJECTIVE: To determine the relative risk (RR) of major congenital malformations (MCMs) in infants with antenatal exposure to antiepileptic drug (AED) dual therapy and to explore the influence of specific AEDs vs dose. METHODS: All completed pregnancies prospectively enrolled in the Kerala Registry of Epilepsy and Pregnancy from 1998 until December 2013 on AED dual therapy exposure during the first trimester were analyzed for the outcome, MCMs. Dose was expressed as ratio of prescribed to daily defined dose (PDD/DDD), and the RR for malformation was referenced to lamotrigine monotherapy. RESULTS: Of 1,688 completed pregnancies, 368 women were on dual therapy. The risk of MCM with dual therapy was 1.6 times more than with monotherapy (p = 0.0015). The frequency of renal, alimentary, and skeletal malformations was higher with dual therapy, while cardiac malformations were more common with monotherapy. The risk of MCM was highest with topiramate dual therapy (14.82, 95% confidence interval [CI] 1.88-113.83). No MCMs were seen with levetiracetam or lamotrigine dual therapy. There was a marked reduction in the risk of MCM when dual therapies involving topiramate or valproate were excluded (RR 1.78, 95% CI 1.00-3.15). The risk of MCM with dual therapy was higher even at lower doses (8.2%, PDD/DDD 0.5-1), and the subsequent dose-dependent increment was less profound than with monotherapy. CONCLUSIONS: Our data indicate that the excess risk of dual therapy over monotherapy is contributed largely by topiramate or valproate. The complex pharmacokinetic and pharmacodynamic effects of dual therapy adversely influence MCM risk.