Reduced brain volumes in children of women with epilepsy: A neuropsychological and voxel based morphometric analysis in pre-adolescent children

Risk of Autism after Prenatal Topiramate, Valproate, or Lamotrigine Exposure

BACKGROUND

Maternal use of valproate during pregnancy has been associated with an increased risk of neurodevelopmental disorders in children. Although most studies of other antiseizure medications have not shown increased risks of these disorders, there are limited and conflicting data regarding the risk of autism spectrum disorder associated with maternal topiramate use.

METHODS

We identified a population-based cohort of pregnant women and their children within two health care utilization databases in the United States, with data from 2000 through 2020. Exposure to specific antiseizure medications was defined on the basis of prescription fills from gestational week 19 until delivery. Children who had been exposed to topiramate during the second half of pregnancy were compared with those unexposed to any antiseizure medication during pregnancy with respect to the risk of autism spectrum disorder. Valproate was used as a positive control, and lamotrigine was used as a negative control.

RESULTS

The estimated cumulative incidence of autism spectrum disorder at 8 years of age was 1.9% for the full population of children who had not been exposed to antiseizure medication (4,199,796 children). With restriction to children born to mothers with epilepsy, the incidence was 4.2% with no exposure to antiseizure medication (8815 children), 6.2% with exposure to topiramate (1030 children), 10.5% with exposure to valproate (800 children), and 4.1% with exposure to lamotrigine (4205 children). Propensity score-adjusted hazard ratios in a comparison with no exposure to antiseizure medication were 0.96 (95% confidence interval [CI], 0.56 to 1.65) for exposure to topiramate, 2.67 (95% CI, 1.69 to 4.20) for exposure to valproate, and 1.00 (95% CI, 0.69 to 1.46) for exposure to lamotrigine.

CONCLUSIONS

The incidence of autism spectrum disorder was higher among children prenatally exposed to the studied antiseizure medications than in the general population. However, after adjustment for indication and other confounders, the association was substantially attenuated for topiramate and lamotrigine, whereas an increased risk remained for valproate. (Funded by the National Institute of Mental Health.).

Are Brain and Cognitive Reserve Shaped by Early Life Circumstances?

When growing older, many people are faced with cognitive deterioration, which may even amount to a form of dementia at some point in time. Although neuropathological signs of dementia disorders can often be demonstrated in brains of patients, the degree to which clinical symptoms are present does mostly not accurately reflect the amount of neuropathology that is present. Sometimes existent pathology even goes without any obvious clinical presentation. An explanation for this phenomenon may be found in the concept of reserve capacity. Reserve capacity refers to the ability of the brain to effectively buffer changes that are associated with normal aging processes and to cope with pathological damage. A larger reserve capacity has been suggested to increase resilience against age-associated cognitive deterioration and dementia disorders. Traditionally, a division has been made between brain reserve, which is based on morphological characteristics of the brain, and cognitive reserve, which is based on functional characteristics of the brain. The present review discusses the premises that brain and cognitive reserve capacity are shaped by prenatal and early postnatal factors. Evidence is accumulating that circumstances during the first 1,000 days of life are of the utmost importance for the lifelong health of an individual. Cognitive deterioration and dementia disorders may also have their origin in early life and a potentially important pathway by which the early environment affects the risk for neurodegenerative diseases is by developmental programming of the reserve capacity of the brain. The basic idea behind developmental programming of brain and cognitive reserve is explained and an overview of studies that support this idea is presented. The review is concluded by a discussion of potential mechanisms, synthesis of the evidence and relevance and future directions in the field of developmental origins of reserve capacity.

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.

Of differing methods, disputed estimates and discordant interpretations: the meta-analytical multiverse of brain volume and IQ associations

Brain size and IQ are positively correlated. However, multiple meta-analyses have led to considerable differences in summary effect estimations, thus failing to provide a plausible effect estimate. Here we aim at resolving this issue by providing the largest meta-analysis and systematic review so far of the brain volume and IQ association (86 studies; 454 effect sizes from k = 194 independent samples; N = 26 000+) in three cognitive ability domains (full-scale, verbal, performance IQ). By means of competing meta-analytical approaches as well as combinatorial and specification curve analyses, we show that most reasonable estimates for the brain size and IQ link yield r-values in the mid-0.20s, with the most extreme specifications yielding rs of 0.10 and 0.37. Summary effects appeared to be somewhat inflated due to selective reporting, and cross-temporally decreasing effect sizes indicated a confounding decline effect, with three quarters of the summary effect estimations according to any reasonable specification not exceeding r = 0.26, thus contrasting effect sizes were observed in some prior related, but individual, meta-analytical specifications. Brain size and IQ associations yielded r = 0.24, with the strongest effects observed for more g-loaded tests and in healthy samples that generalize across participant sex and age bands.

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.