Differences in factors influencing the familial aggregation of febrile convulsion in population and hospital patients

Febrile seizures reduce hippocampal subfield volumes but not cortical thickness in children with focal onset seizures

OBJECTIVES

Whether febrile seizures (FS) produce long-term injury to the hippocampus or other brain structures is a critical question concerning focal onset seizures in children. Our aims are to evaluate the effect of FS on subfields of the hippocampus, thalamic nuclei, amygdala, cortical thickness, and surface area quantitatively in children with FS who later developed focal seizures and to identify biomarkers based on MRI structures.

METHODS

Children who had focal onset seizures with or without previous FS and normal 3-T MRI findings were included retrospectively. The MRI was performed within 2 years after the onset of focal seizures. Age-matched controls were also recruited. Hippocampal subfields and thalamic nuclei, amygdala volumes, cortical thickness, and cortical surface area in individual cortical regions were segmented by FreeSurfer version 7.1.1. Volumetric and morphometric data among children who had focal seizures with or without previous FS, as well as controls, were compared and correlated with clinical parameters.

RESULTS

Children with a history of FS who had focal seizures exhibited smaller right cornu ammonis (CA) 1 and right molecular cell layer of the hippocampus, compared to those without FS. A larger left hippocampal fissure was also found in FS with focal seizures compared to age-matched controls. There were no statistically significant differences in each nucleus of the thalamus, amygdala, cortical thickness, and surface area of each cortical region among the three groups. A smaller whole hippocampal volume was found for the right hippocampus in children with FS and focal seizures compared to those without FS. A trend of negative correlation was found between the frequency of FS and the left and right CA1 subfield volume ratios of the hippocampus.

CONCLUSIONS

We concluded that multiple episodes of FS may be associated with a trivial difference in volume reduction in the CA1 and molecular layer of the right hippocampus and an enlarged hippocampal fissure of the left hippocampus, but not with individual cortical thicknesses, surface area, thalamic nuclei, or amygdala in children with focal onset seizures.The hippocampal subfield CA1 and molecular layer of the right hippocampus may be more vulnerable than the cortices in children with focal seizures who experienced multiple FS episodes. This study highlights the minimal differences in brain volumes among children with recent onset focal seizures with or without FS history and controls, suggesting that the brain injurious aspects of the FS and recent onset focal seizures may have been previously overstated. This suggests that physicians can be reassuring about brain injury associated with these seizure types when discussing outcomes with parents and patients.

Association between ANKK1 (rs1800497) polymorphism of DRD2 gene and attention deficit hyperactivity disorder: a meta-analysis

The role of dopamine neurotransmitter in attention deficit hyperactivity disorder (ADHD) remains controversial. Many molecular studies focusing on dopamine receptors have attempted to analyze the gene polymorphisms involved in dopaminergic transmission. Of these, rs1800497 (TaqIA) single nucleotide polymorphism (SNP) of the dopamine D2 receptor (DRD2) gene has been focused on by the most attention. However, this locus has recently been identified within the exon 8 of ankyrin repeat and kinase domain containing 1 (ANKK1), giving rise to a Glu713-to-Lys substitution in the putative ANKK1 protein. Thus, we performed a meta-analysis to determine whether ANKK1 polymorphism influences the risk of ADHD and examined the relationship between rs1800497 genetic variant and the etiology of ADHD. Relevant case-control studies were retrieved by database searches and selected according to established inclusion criteria. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the associations. Meta-regression, subgroup analysis, sensitivity analysis and cumulative meta-analysis were performed. A total of 11 studies with 1645 cases and 1641 controls were included. In the dominant model, the rs1800497 locus was associated with ADHD, with a pooled OR of 1.785 (95% CI=1.068-2.984, p=0.027). Subgroup analysis for ethnicity indicated that the polymorphism was associated with ADHD in Africans (OR=3.286, 95% CI=1.434-7.527, p=0.005), but not in East Asians (OR=1.513, 95% CI=0.817-2.805, p=0.188) and Caucasians (OR=1.740, 95% CI=0.928-3.263, p=0.084). However, the results of meta-regression indicated that publication date (p=0.601), source of controls (p=0.685), ethnicity (p=0.755) and diagnostic criteria (p=0.104) could not explain the potential sources of heterogeneity. This meta-analysis indicates that the rs1800497 locus may be associated with ADHD. These data provide possible references for future case-control studies in childhood disorders.

Facial emotion recognition in childhood: the effects of febrile seizures in the developing brain

It has been documented that anteromedial temporal lobe dysfunction can cause impairment in emotional intelligence. In particular, medial temporal lobe epilepsy (MTLE) is associated with disorders in emotion recognition from facial expressions. About one-third of patients with MTLE experienced febrile seizures (FSs) during childhood. In the present study, we investigated facial emotion recognition ability in a group of 38 school-aged children with antecedent FSs and in an age- and sex-matched control group. Children with abnormal general visuoperceptual abilities were excluded. Children with FSs showed lower recognition scores versus controls in both matching (28.64 vs 33.47; p<.0001) and labeling (21.25 vs 23.03; p=.001) facial emotions. Our findings support the hypothesis that FSs can be associated during childhood with a dysfunction within the neural network subserving the processing of facial expressions of the basic emotions.

Developing and refining the Taiwan Birth Cohort Study (TBCS): five years of experience

The Taiwan Birth Cohort Study (TBCS) is the first nationwide birth cohort database in Asia designed to establish national norms of children's development. Several challenges during database development and data analysis were identified. Challenges include sampling methods, instrument development and statistical approach to missing data. The purpose of this paper is to describe the pilot study underpinning the TBCS, testing of the TBCS developmental instrument and the resolution of methodological challenges. Bayesian analysis fill in missing data, three-step regression analysis for the investigation of mediating and moderating effect, the use of structural equation modeling in a large scale investigation, investigating direct and indirect effects, confounding factors and reciprocal relationships in children's development, and used latent growth model in longitudinal observations are described. The TBCS will provide ongoing longitudinal information regarding the predisposing and maintaining factors affecting the long term outcome of pediatric illnesses.

The long-term effects of febrile seizures on the hippocampal neuronal plasticity - clinical and experimental evidence

Febrile seizures are the most common seizure disorder in childhood, but their long-term effects on the developing brains especially neuronal injury and neurocognitive function remain unresolved. Recent epidemiological studies reassure that most febrile seizures do not adversely affect global intelligence and hippocampal function, such as memory. However, there are concerns regarding those children who experience febrile seizures during the first postnatal year, having prior developmental delay and pre- or peri-natal events. Magnetic resonance imaging (MRI) studies confirmed that prolonged and focal FS can occasionally produce acute hippocampal injury that evolves into atrophy. Animal studies have revealed that the exposure of hippocampal neurons to experimental febrile seizures early in life, particularly prolonged or frequently repetitive FS, or together with brain malformation, may lead to sustained dysfunction of these cells, in spite of the absence of neuronal damage. Genetic studies suggest that the relationship between febrile seizures and subsequent epilepsy and neurocognitive dysfunction is sometimes genetic, but there are complex interactions with genetic or environmental modifiers. Therefore, there is a small group of children in whom febrile seizures-induced hippocampal injury might occur. Identification of the target population for subsequent mesial temporal sclerosis is important for prevention and early intervention.

Effects of sociodemographic factors on febrile convulsion prevalence

BACKGROUND

The aim of the present study was to determine the lifetime risk (LTR) of febrile convulsion and the effects of socioeconomic factors affecting this risk among school children in Izmir province, Turkey.

METHODS

Information was collected from school children aged 7-17 years in a school-based cross-sectional study. Stratified cluster sampling technique was used to define the study population, which represents the schools located in the metropolitan area of Izmir. Data were collected through a standard questionnaire from the parents.

RESULTS

LTR was 9.7% (girls, 9.3%; boys, 10.1%, P > 0.05). The risk of febrile convulsion for children whose fathers' education level was equal to or less than primary school was 2.13 (95% confidence interval [CI]: 1.1-4.0) and, for children whose fathers were blue collar workers it was 1.4 (95%CI: 1.0-1.8).

CONCLUSION

LTR for febrile convulsion was relatively high in this population, consistent with studies from other developing countries. Lower socioeconomic status and lack of knowledge about febrile convulsions were main factors related to this risk.

Febrile convulsions: development and validation of a questionnaire to measure parental knowledge, attitudes, concerns and practices

BACKGROUND

The best medicine for febrile convulsions (FCs) is not prescription medications but effective communication of related information to parents. Therefore, a quick assessment tool for obtaining information about parental responses to FCs is essential for educating parents, clinical practice and research. This paper describes the development and psychometric testing of a questionnaire on parental knowledge, attitudes, concerns and practices (KACP) toward FC.

METHODS

Questionnaire items were created via literature review, interview, and expert consultation. Ten parents were interviewed to develop the questionnaire contents. Nine experts and seven parents were consulted to review the content and face validity of the questionnaire. Of the 326 parents of children with FC visiting 11 emergency departments in southern Taiwan, 216 parents completed the questionnaire, and 64 completed the questionnaire again 2 weeks later. Content validity, internal consistency, test-retest reliability, and item analysis were evaluated.

RESULTS

Cronbach's alpha exceeded 0.72 for the knowledge, attitudes and concerns domains. The item-total correlations in the knowledge and concerns domains ranged from 0.40 to 0.73, but were lower in the attitudes domain (only 4 in 10 items were within 0.40-0.70). The intraclass correlation coefficients (ICC) for the test-retest reliability of the knowledge, attitudes and concerns domains were 0.65, 0.68 and 0.58, respectively. The correlation coefficients between KACP domains were tested and significantly supported the theoretical basis of the questionnaire.

CONCLUSION

For research purposes, the KACP questionnaire measures parental responses with a moderate level of reliability and validity. Cross-cultural investigation of the questionnaire is needed to facilitate its use in other countries.

Parental responses to first and recurrent febrile convulsions

OBJECTIVE

To compare parental knowledge, attitudes, concerns, and first-aid practices for children experiencing febrile convulsions (FC).

SUBJECTS AND METHODS

A questionnaire was mailed to 326 FC parents from 11 emergency departments in southern Taiwan.

RESULTS

A total of 109 first- and 107 recurrent-FC parents responded 1-3 months after the FC. Most incorrectly believed an electroencephalogram (EEG) or computed tomography (CT) was necessary; immunization should be postponed, and overestimated the risk of subsequent epilepsy. Parents were concerned about further attacks in the night, fever episodes, and frequently measured the child's body temperature. During the first episode, objects were inserted into the child's mouth and they were rushed to a hospital. One third lowered the child's body temperature, and 15% positioned the children on their side. For subsequent seizures, 80% anticipated rushing the child to a hospital, and 44% would put objects into the child's mouth. In comparison, although the recurrent-FC parents had higher scores in knowledge and attitudes than the first-FC parents, low knowledge scores (40% correct) were seen in both groups. No significant differences were found on parental concerns, performed/anticipated first aid for FC.

CONCLUSION

Most FC parents had inadequate knowledge, high concerns, and improper first-aid practices. This suggests that parents with either first- or recurrent-FC children need information, emotional support, and first-aid demonstrations.

Parental concerns for the child with febrile convulsion: long-term effects of educational interventions

OBJECTIVE

To evaluate long-term effects of educational interventions on parental concerns for children with febrile convulsions (FC).

SUBJECTS AND METHODS

209 FC parents were recruited from southern Taiwan, and assigned into program or pamphlet groups by their choices. A questionnaire was used to examine the parental concerns at 4 time points: prior to the interventions, 3 months, 1 year, and 2 years after the interventions.

RESULTS

The concern scores were high before the interventions. Parents concerned that their child is apt to get a fever, has further seizures in the night, that FC results in potential brain damage and is life threatening. After interventions the concern scores were significantly lower for the program group than for the pamphlet group. The educational program was the most significant factor that influenced the change in parental concerns. The recurrence of FC did not significantly influence the change in the concern trajectory in the program group but showed a significant difference in the pamphlet group.

CONCLUSION

FC parental concerns decreased as time passed particularly in the program group. The educational program was the significant factor that influenced the change of concern trajectories, and the recurrent/non-recurrent factor influenced the change of concern only in pamphlet group. FC parental concerns should be assessed, and information given combined with emotional support.

Neurocognitive attention and behavior outcome of school-age children with a history of febrile convulsions: a population study

PURPOSE

A prospective population-based case-control study was performed to ascertain whether febrile convulsion (FC) in early childhood is associated with neurocognitive attention deficits in school age.

METHODS

A total of 103 children, confirmed to have FC by age 3 years from a population survey of 4,340 live-birth newborns in Tainan City, Taiwan, was followed up until at least age 6 years. An achievement test, behavioral ratings, and computerized neurocognitive battery assessing various subcomponents of attention were given to 87 FC children (FC group) and 87 randomly selected population-matched control (CC group).

RESULTS

Compared with the CC group, the FC group did not have scholastic performance or behavioral outcome disadvantage. Overall FC group performance was distinguished by significantly higher scores in the achievement test and fewer missing errors (p < 0.005) and commission errors (p < 0. 05), less variability in reaction time (p < 0.005), and a nonsignificant trend of impulsivity. Attention performance of the FC and CC groups were comparable. Within the FC group, age at onset, complex FC, recurrence of FC, development of unprovoked seizures, or prior use of phenobarbital had no adverse effects on neurocognitive attention outcome.

CONCLUSIONS

This population study suggests that FC in early childhood does not have adverse effects on behavior, scholastic performance, and neurocognitive attention. On the contrary, the FC group demonstrated significantly better control of distractibility and attention at school age.

Risk factors for a first febrile convulsion in children: a population study in southern Taiwan

PURPOSE

To identify risk factors for a first febrile convulsion among 3-year-old children by a matched case-control population study.

METHODS

All 11,714 neonatal survivors born in Tainan City between October 1989 and September 1991 were enrolled. At age 3, 10,460 children were available for telephone survey for febrile convulsions, and were confirmed by home visit interviews. Those without history of seizure were randomly matched to each febrile convulsion case by age, gender, and residence district.

RESULTS

Two hundred fifty six children had febrile convulsions, and 218 of them and their matched controls were available for analysis. The febrile convulsion cases had significantly more febrile episodes (four or more) per year (33.0 vs. 22.5%; p = 0.021), and cases had a higher percentage of developmental delay (3.7 vs. 0.4%; p = 0.046) and a higher percentage of febrile convulsions in their siblings (12 vs. 0.4%; p = 0.011) than controls. The other sociodemographic, environmental, and biologic variables showed no differences between cases and controls. Step-wise logistic regression showed a highly significant independent association between febrile convulsions and history of febrile convulsions in the siblings, and a moderate one between febrile convulsions and the number of febrile episodes per year.

CONCLUSIONS

The presence of febrile convulsions in the siblings and the number of fever episodes per year were the independent and significant predictors of febrile convulsion for an individual case in our population-based sample.

Hereditary febrile seizures: phenotype and evidence for a chromosome 19p locus

The occurrence of febrile seizures (FSs) in large autosomal dominant FS kindreds makes possible accurate delineation of the pure clinical phenotype of hereditary FS among secondary FS cases, and the identification of gene loci causing susceptibility to FS. Recently FS gene loci on chromosomes 8 and 19 were identified. We studied the phenotype of FS in four large families in which FS is an autosomal dominant trait. Among 30 affected secondary FS cases, mean age of onset was 16.3 months (range 4 to 36 months), sex ratio was equal, and 43% were complex (13 of 30). Among these 30 secondary FS cases, the mean number of FSs was 2.1, half had only a single FS, and none had afebrile seizures. Penetrance was 0.67, approximately the same as in our previous larger group of 40 multicase FS families (0.64). The occurrence of DPT encephalopathy in a sib of a patient with FS raises the possibility that these two etiologies are related. Linkage studies showed that one of the four families (Family 1) was linked to chromosome 19p markers, none of the families was linked to chromosome 8q markers, and the largest FS family (Kindred 6) was unlinked to either 19p or 8q markers, supporting the hypothesis of genetic heterogeneity for FS.

Effects of an educational program on parents with febrile convulsive children

The purpose of this study was to characterize the effects of an educational program on knowledge, attitude, concern, and first-aid measures among parents with febrile convulsive children. All parents completed a pretest questionnaire 3 weeks before the meeting. The parents were assigned randomly into experimental (n = 65) and control (n = 64) groups on the day they attended the program. The control group completed the identical questionnaire (posttest) before the program, whereas the experimental group completed the same posttest after the program. In pretest, most parents considered electroencephalogram or computed tomography necessary in evaluating their children, suggested that immunization be postponed, and rated the risk of subsequent epilepsy as high for their children. Most of them favored frequent body temperature measurement, were very anxious about further febrile convulsion episodes during the night, and were fever phobic. After education, although only a slight change in fever anxiety was found, the experimental group showed significant improvement in knowledge, attitude, concerns, and anticipatory practice of febrile convulsion compared with the control group. In conclusion the parents' poor knowledge, negative attitudes, anxiety, and inadequate first-aid measures toward febrile convulsion can be effectively improved by an educational intervention program.