Focal Febrile Seizures Research Articles

Brain Perfusion, Hippocampal Volumetric, and Diffusion-weighted Imaging Findings in Children with Prolonged Febrile Seizures and Focal Febrile Seizures.

ABSTRACTBackground:The current study was conducted to describe the findings of brain perfusion, hippocampal volumetric, and diffusion-weighted imaging (DWI) in children aged six months to seven years with febrile status epilepticus (FSE) and focal febrile seizures (FFS) when compared with age and gender-matched controls.Materials and Methods:This cross-sectional study was conducted among children aged six months to seven years presenting with FSE or FFS within 72 h of the seizure. Cases were subjected to magnetic resonance imaging (MRI) brain and sleep-deprived electroencephalography. Age and gender-matched children who were subjected to MRI brain for nonepileptic indications served as their control. Hippocampal volumes, T2 values, cerebral blood flow, and diffusion characteristics were compared between the cases and controls and also between those with FSE and FFS.Results:A total of 31 cases (FFS = 20, FSE = 11) and 30 controls were enrolled. There was no significant difference between right and left hippocampal volumes and T2 relaxometry values between cases and controls and also between children with FSE and FFS. Similarly, the cerebral blood flow was also comparable in cases and controls. There was a single case of FSE with hippocampal malrotation; one child showed diffusion restriction in the hippocampus after prolonged (>60 min) FSE.Conclusion:Children with FSE and FFS had comparable hippocampal volume and brain perfusion to healthy children. However, one child with FSE had hippocampal malrotation and another had diffusion restriction. The study findings need to be interpreted in the context of small sample size, and lack of follow-up neuroimaging.

Short-term neurodevelopmental outcomes of focal febrile seizures

ObjectiveThe effect of complex febrile seizures (FS), specifically focal FS, on long-term neurodevelopmental outcome is not well known. The aim of this study was to assess the association between complex FS and neurodevelopmental outcome. MethodsA single-center, retrospective, cohort study was performed. The study included 282 children aged 6–60 months who experienced FS. Of these, 61 (22%) experienced recurrent FS, 33 (12%) prolonged FS, and 17 (6%) focal FS. The effect of these complex FS on subsequent need for special neurodevelopmental support was investigated. The neurodevelopmental status after FS was evaluated by a questionnaire. ResultsDuring a median follow-up period of 3 years post FS, 12 children (4.3%) required special neurodevelopmental support. Univariate analysis demonstrated a significant association between focal FS and the need for subsequent special neurodevelopmental support, as well as a correlation between prolonged FS and pre-existing neurodevelopmental abnormality. Multiple logistic regression analysis demonstrated that focal FS (odds ratio [OR]: 12.27; 95% confidence interval [CI]: 2.11–71.22) and pre-existing neurodevelopmental abnormality (OR: 262; 95% CI: 17–3944) were significantly associated with the need for subsequent special support. ConclusionAn association was found between focal FS and subsequent neurodevelopmental impairment; therefore, close follow-up with particular attention to neurodevelopmental status is required for children who experience focal FS.

Republication de : Évaluation d’un enfant après une crise fébrile : focus sur trois problèmes de pratique clinique

Febrile seizures (FS) are the most common seizures seen in the paediatric population in the out-of-hospital and emergency department settings, and they account for the majority of seizures seen in children younger than 5 years old. An FS is a seizure accompanied by fever, without central nervous system infection, occurring in children between 6 months and 5 years old. Five criteria have been used and taught to classify any FS as simple or complex FS. These factors do not bear the same significance for clinical practice, in particular, the decision to perform a lumbar puncture for cerebrospinal fluid analysis to rule out an intracranial infection. Moreover, epidemiological studies have illustrated that some factors are predictive of febrile seizure recurrence while others are predictive of epilepsy occurrence. On this basis, a workshop was organized to provide an answer to three clinical practice questions: when should a lumbar puncture be performed in a child who has experienced a seizure during a fever episode, is the prescription of a rescue drug required with a risk of a prolonged febrile seizure recurrence, when should a neurological consultation be requested (risk of later epilepsy)? Based on a review of the literature and on a 1-day workshop, we report here the conclusion of the working group. A lumbar puncture is required in any child with meningitis symptoms or septic signs or behaviour disturbance. A lumbar puncture should be discussed based on the clinical symptoms and their progression over time when a child has experienced a focal FS or repetitive FSs without signs of meningitis or sepsis or behaviour disturbance. The lumbar puncture is not necessary in case of simple FS without signs of meningitis, including in infants between 6 and 12 months old. An early clinical evaluation (at least 4 h after the first clinical assessment) could be helpful, in particular in infants younger than 12 months of age. A rescue drug might be prescribed when there is a high risk of prolonged FS (i.e., risk higher than 20 %): age at FS<12months OR a history of a previous febrile status epilepticus OR if the first FS was a focal seizure OR abnormal development/neurological exam/MRI OR a family history of nonfebrile seizure. A neurological consultation should be requested for any child who has experienced a prolonged FS before the age of 1 year, for children who have experienced prolonged and focal FS or repetitive (within 24h) focal FS, for children who have experienced multiple complex (focal or prolonged or repetitive) FS, for children with an abnormal neurological exam or abnormal development experiencing a FS. Although childhood febrile seizures in most cases are benign, witnessing such seizures is always a terrifying experience for the child's parents. Most parents feel that their child is dying or could have severe brain injury related to the episode. Therefore, the group also suggests a post-FS visit with the primary care physician.

Évaluation d’un enfant après une crise fébrile : focus sur trois problèmes de pratique clinique

Febrile seizures (FS) are the most common seizures seen in the paediatric population in the out-of-hospital and emergency department settings, and they account for the majority of seizures seen in children younger than 5 years old. An FS is a seizure accompanied by fever, without central nervous system infection, occurring in children between 6 months and 5 years old. Five criteria have been used and taught to classify any FS as simple or complex FS. These factors do not bear the same significance for clinical practice, in particular, the decision to perform a lumbar puncture for cerebrospinal fluid analysis to rule out an intracranial infection. Moreover, epidemiological studies have illustrated that some factors are predictive of febrile seizure recurrence while others are predictive of epilepsy occurrence. On this basis, a workshop was organized to provide an answer to three clinical practice questions: when should a lumbar puncture be performed in a child who has experienced a seizure during a fever episode, is the prescription of a rescue drug required with a risk of a prolonged febrile seizure recurrence, when should a neurological consultation be requested (risk of later epilepsy)? Based on a review of the literature and on a 1-day workshop, we report here the conclusion of the working group. A lumbar puncture is required in any child with meningitis symptoms or septic signs or behaviour disturbance. A lumbar puncture should be discussed based on the clinical symptoms and their progression over time when a child has experienced a focal FS or repetitive FSs without signs of meningitis or sepsis or behaviour disturbance. The lumbar puncture is not necessary in case of simple FS without signs of meningitis, including in infants between 6 and 12 months old. An early clinical evaluation (at least 4 h after the first clinical assessment) could be helpful, in particular in infants younger than 12 months of age. A rescue drug might be prescribed when there is a high risk of prolonged FS (i.e., risk higher than 20%): age at FS<12months OR a history of a previous febrile status epilepticus OR if the first FS was a focal seizure OR abnormal development/neurological exam/MRI OR a family history of nonfebrile seizure. A neurological consultation should be requested for any child who has experienced a prolonged FS before the age of 1 year, for children who have experienced prolonged and focal FS or repetitive (within 24h) focal FS, for children who have experienced multiple complex (focal or prolonged or repetitive) FS, for children with an abnormal neurological exam or abnormal development experiencing a FS. Although childhood febrile seizures in most cases are benign, witnessing such seizures is always a terrifying experience for the child's parents. Most parents feel that their child is dying or could have severe brain injury related to the episode. Therefore, the group also suggests a post-FS visit with the primary care physician.

Experimental febrile seizures impair interastrocytic gap junction coupling in juvenile mice.

Prolonged and focal febrile seizures (FSs) have been associated with the development of temporal lobe epilepsy (TLE), although the underlying mechanism and the contribution of predisposing risk factors are still poorly understood. Using a kainate model of TLE, we previously provided strong evidence that interruption of astrocyte gap junction-mediated intercellular communication represents a crucial event in epileptogenesis. To elucidate this aspect further, we induced seizures in immature mice by hyperthermia (HT) to study the consequences of FSs on the hippocampal astrocytic network. Changes in interastrocytic coupling were assessed by tracer diffusion studies in acute slices from mice 5 days after experimental FS induction. The results reveal that HT-induced FSs cause a pronounced reduction of astrocyte gap junctional coupling in the hippocampus by more than 50%. Western blot analysis indicated that reduced connexin43 protein expression and/or changes in the phosphorylation status account for this astrocyte dysfunction. Remarkably, uncoupling occurred in the absence of neuronal death and reactive gliosis. These data provide a mechanistic link between FSs and the subsequent development of TLE and further strengthen the emerging view that astrocytes have a central role in the pathogenesis of this disorder. © 2016 Wiley Periodicals, Inc.

Clinicoradiological description of two children with hemiconvulsion-hemiplegia-epilepsy syndrome

Hemiconvulsion-hemiplegia-epilepsy syndrome is an uncommon consequence of prolonged focal febrile convulsive seizures in infancy and early childhood. We report two cases of hemiconvulsion-hemiplegia-epilepsy syndrome who presented acutely and had striking neuroimaging findings suggestive of diffuse cytotoxic edema confined to one hemisphere as documented by magnetic resonance imaging, including extensive diffusion weighted imaging abnormalities in both the cases.

Genetic influence on the clinical characteristics and outcome of febrile seizures—a retrospective study

To assess the influence of the family history (FH) of epilepsy or febrile seizures (FSs) on the clinical presentation of FSs and on their outcome. We reviewed the charts of 482 children admitted to the Ste-Justine Hospital with FSs between 3 months and 6 years of age and followed for at least 5 years. Children with a positive FH of epilepsy (n=67) showed significantly more focal and recurrent FSs than those without such a FH. The risk of developing partial epilepsy (n=17) or generalized epilepsy (n=19) was significantly greater in children with focal or recurrent FSs, respectively. In children with focal FSs, only two out of 30 (6.7%) children with a negative FH of epilepsy developed partial epilepsy compared with four out of nine (44.4%) children with a positive FH. In children with recurrent FSs, as much as seven out of 34 (20.6%) children with a positive FH of epilepsy developed generalized epilepsy compared to only eight out of 161 (0.05%) of those with a negative FH. Nevertheless, when not taking into account the clinical presentation of FSs, the positive FH of epilepsy constituted a risk factor for developing generalized but not partial epilepsy. Finally, children with a positive FH of FSs (n=120) exhibited significantly more recurrent FSs than those without such a FH, but this did not modify the risk of epilepsy. The FH of FSs and/or epilepsy should be taken into account when evaluating the risk of FSs recurrence and of epilepsy.

Febrile seizures and mesial temporal sclerosis.

The sequence of febrile seizures followed by intractable temporal lobe epilepsy is rarely seen from a population perspective. However, several studies have shown a significant relationship between a history of prolonged febrile seizures in early childhood and mesial temporal sclerosis. The interpretation of these observations remains quite controversial. One possibility is that the early febrile seizure damages the hippocampus and is therefore a cause of mesial temporal sclerosis. Another possibility is that the child has a prolonged febrile seizure because the hippocampus was previously damaged by a prenatal or perinatal insult or by genetic predisposition. Imaging studies have shown that prolonged and focal febrile seizures can produce acute hippocampal injury that evolves to hippocampal atrophy, and that complex febrile seizures can originate in the temporal lobes in some children. Several lines of evidence now indicate that genetic predisposition is an important causal factor of febrile seizures and mesial temporal sclerosis. From recent clinical and molecular genetic studies, it appears that the relationship between febrile seizures and later epilepsy is frequently genetic, and there are several syndrome-specific genes for febrile seizures. Mesial temporal sclerosis probably has different causes. A number of retrospective studies showed that complex febrile seizures are a causative factor for the later development of mesial temporal sclerosis and temporal lobe epilepsy. However, contradictory results have come from several prospective and retrospective studies. The association between febrile seizures and temporal lobe epilepsy probably results from complex interactions between several genetic and environmental factors.

Do prolonged febrile seizures produce medial temporal sclerosis? Hypotheses, MR1 evidence and unanswered questions

Whether or not severe febrile seizures in infancy cause hippocampal injury and subsequent medial temporal sclerosis is an often debated question in epilepsy. Recent magnetic resonance imaging (MRI) of infants suffering from febrile seizures has provided preliminary evidence that abnormally increased T2 signal intensity can be seen in the hippocampi of infants following prolonged and focal febrile seizures. Follow-up MRIs in a few of these infants have confirmed that medial temporal sclerosis can develop following these acute MRI signal changes. In this article, we review the hypotheses and MRI evidence relating to hippocampal injury during prolonged febrile seizures and the later development of medial temporal sclerosis.