Febrile seizures and increased stress sensitivity in children: How it relates to seizure characteristics.

BACKGROUND: Studies suggest that the relationship between seizures and stress starts early in life. However, evidence of long-term altered stress reactivity following early-life seizures is lacking. Our objectives were to assess alterations in stress hormone reactivity in children with past febrile seizures (FS) and investigate how these alterations relate to clinical characteristics. METHOD: This case-control study compared a convenience sample of children with simple FS (n = 24), complex FS (n = 18), and matched healthy controls (n = 42). Stress was induced by electrode placement for an electroencephalography (EEG) exam. Salivary cortisol to stress, using three samples collected before and after the stressor, was compared between groups and sex. The relationship between stress reactivity and clinical characteristics (i.e., FS duration, age at first FS, time since the last FS) was investigated. RESULTS: Cortisol reactivity to stress was significantly different depending on study groups, F(1, 78) = 6.415, p = 0.003, η2p = 0.141, but not sex nor was there a significant interaction between group and sex (p ≥ 0.581). Participants with simple FS showed higher cortisol reactivity to stress (M = 14.936, Standard deviation (SD) = 26.852) compared with those with complex FS (M = -4.663, SD = 18.649, p = 0.015) and controls (M = -3.817, SD = 18.907, p = 0.003). There was no significant difference between participants with complex FS and controls (p > 0.999). Stress reactivity was not linked to clinical characteristics. CONCLUSIONS: Children with past simple FS showed greater changes in salivary cortisol following stress, suggesting enhanced stress sensitivity. As similar results were not found in a population with complex FS, our study shows that stress alterations are not caused by seizure severity. Future studies are needed to investigate whether stress sensitivity may be premorbid to simple FS and may contribute to simple FS incidence.

Cognitive and behavioural development in children presenting with complex febrile seizures: at onset and school age.

OBJECTIVE: Our goal was to assess development, cognition and behaviour following an initial complex febrile seizure (FS), at onset and school age, in the context of known risk factors for cognitive development. METHODS: Two cohorts were recruited. Thirty-five infants with an initial complex FS were assessed within the first year post-seizure and compared to 30 controls (simple FS) based on measures of cognitive, motor and language development, behaviour and emotions. Additionally, 19 school-age children with previous complex FS (11 multiple, eight prolonged) were assessed and compared to 19 controls (simple FS) based on measures of intelligence, learning/memory, executive functioning, behaviour and emotions. RESULTS: Within the first year post-onset, infants with complex FS did not significantly differ from controls based on developmental measures. Seizure duration and age at seizure onset did not impact developmental outcome. School-age children with complex FS showed unaltered global intelligence, but lower executive functioning, compared to controls. Children with prolonged FS also showed evidence of a lower level of learning and memory abilities. Neuropsychological scores correlated with seizure duration. Children with complex FS showed more attentional problems and anxious/depressed symptomatology at onset and school age, and more hyperactivity at school age. SIGNIFICANCE: Infants with complex FS seemed to show normal development within the first year post-seizure onset. However, challenges in executive functioning, learning and memory at school age were found in children with a history of FS. Hence, at school age, cognitive challenges cannot be excluded based on undifferentiated early cognitive development, and may occur even in the absence of the most severe form of FS (i.e., FSE). Beyond the limits of this study (i.e., small sample size, use of parental questionnaires for emotional/behavioural outcome, absence of focal cases in the school-age cohort), our results suggest that a follow-up is necessary beyond the early preschool years in order to understand the long-term outcome.

Cognitive outcome of status epilepticus in children.

Epileptic encephalopathy encompasses conditions in which cognitive, motor, or sensory deficits result as a consequence of epileptic activity defining certain syndromes. It therefore represents a more severe subset of epilepsy, which can be generally characterized as frequent or severe seizures leading to cerebral dysfunction. This disturbance in cerebral functioning can in turn hinder, somewhat dramatically, cognitive development and further impact the future lives of patients. In this paper, we describe the cognitive consequences of status epilepticus in children and in adults in the context of plasticity theories. Recent studies maintain that consequences of SE may be severe cognitive sequelae, especially in early life. Since the residual consequences of SE in adulthood seem less detrimental and long-lasting, we argue that early life insults, such as those created by SE, during a rapid period of development and functional specialization, result in specific cognitive deficits dependent on the sensitive period at which SE occurred.