Relationship between benign epilepsy of children with centro-temporal EEG foci and febrile convulsions

Factors Predicting Poor Response to Initial Therapy in Benign Childhood Epilepsy with Centrotemporal Spikes (BCECTS)

Background and Purpose:

Benign childhood epilepsy with centrotemporal spikes (BCECTS) is the most common pediatric focal epilepsy syndrome and typically has positive clinical outcomes. However, a few patients experience recurrent seizures, and therefore, require treatment with antiepileptic drugs (AEDs). This study aimed to identify risk factors associated with poor response to initial AED therapy in BCECTS patients.

Methods:

We retrospectively reviewed the files of 57 patients who were diagnosed with BCECTS between January 2008 and September 2013. Patients not being treated with AEDs have been excluded. We placed the patients into two groups: (1) patients using 1 AED, and (2) patients using 2 AEDs. Clinical characteristics were then collected from the medical records.

Results:

Of the 57 patients, 41 (72%) were successfully treated with 1 AED, and 16 (28%) required 2 AEDs to control seizures. Multiple logistic regression analysis indicated that seizure onset prior to age 5 (odds ratio [OR]: 5.65, 95% confidence interval [CI]: 1.41–22.68) and history of febrile seizures (OR: 4.97, 95% CI: 1.06–23.36) were independent risk factors for poor response to initial therapy (p<0.05). Response to AEDs was not associated with the presence of focal slowing or generalized epileptiform discharges on EEG, abnormalities on MRI of the brain, frequency of afebrile seizures before drug therapy, or family history of febrile seizures or epilepsy.

Conclusions:

This study revealed that 28% of patients with BCECTS experienced poor responses to initial AED therapy. Factors predicting poor response to the initial AED included onset of seizures prior to age 5 and history of febrile seizures.

Pediatric focal epilepsy syndromes

Benign epilepsy with centrotemporal spikes, early-onset childhood occipital epilepsy (Panayiotopoulos syndrome [PS]) and late-onset childhood occipital epilepsy (Gastaut type [LOCE-G]) are the principal pediatric focal epilepsy syndromes. They share major common characteristics: the appearance and resolution of electroclinical features are age related, there is a strong genetic predisposition, the clinical course is often mild with infrequent and easy to control seizures, interictal epileptiform activity is disproportionately abundant when compared with the clinical correlate, and tends to potentiate and generalize during sleep. In this review, we outline the relevant pathophysiology underlying this electroclinical spectrum. Then, the initial description of individual syndromes is followed by a summary of overlapping features and intermediate presentations that question the boundaries between these entities and provide the basis for the concept of a childhood seizure susceptibility syndrome. Additionally, we outline the main features of the related epileptic encephalopathies. An outlook on potential future lines of research completes this review.

10-year outcome of childhood epilepsy in well-functioning children and adolescents

BACKGROUND

A population based study of epilepsy in children from a Swedish county including all children aged 1 month to 16 years was reported in 2006.

AIM

To describe the medical outcome, seizure types, epilepsy syndromes, treatment, individual and family history in children from this study who were well-functioning in January 1997 and the outcome after 10 years.

METHODS

Forty-five individuals, 11-21 years, 19 females, and their parents responded to a questionnaire and the hospital records were reviewed.

RESULTS

At the end of the 10-year period 75.6% of the patients were in remission. Focal seizures and focal seizures with secondary generalization were found in 57.8%. Rolandic epilepsy had been diagnosed in 33.3%, other idiopathic focal epilepsies in 11.0%, cryptogenic and symptomatic focal epilepsies in 22.2%, childhood absence epilepsy in 8.9%, juvenile absence epilepsy and Jeavons syndrome in each 2.2%, West syndrome in 4.4%, and other "generalized" epilepsies in 15.5%. The patients had a history of simple febrile seizures in 15.6% and of primary headache in 24.4%. Monotherapy with antiepileptic drugs was used by 64.4%, and valproate was the most common first drug of choice. A family history of epilepsy was found in 44.4%, febrile seizures in 17.7%, and primary headache in 57.8%. A coincidence of focal and generalized epilepsy phenotypes was found in some families.

CONCLUSIONS

Longitudinal studies are of importance in epilepsy epidemiology. Our results reflect the selection of only well-functioning individuals with epilepsy from the population based original study.

The role of EEG in febrile status epilepticus (FSE)

Febrile status epilepticus is an important neurological emergency and a risk factor for later development of epilepsy. There are guidelines recommending against the use of EEG in the evaluation of simple febrile seizures but the role in febrile status epilepticus is not well established. This article reviews the literature on the role of EEG in the evaluation of the patient with prolonged febrile seizures, summarizes the findings, and concludes with some simple recommendations based upon the existing knowledge. At least 30-40% of EEGs obtained within one week of febrile status epilepticus will contain abnormalities including focal slowing. In some series focal slowing appears to be associated with development of a spike focus in the same location. Prospective series with large numbers of patients and follow-up are required to ascertain whether such abnormalities are associated with later development of epilepsy.

Assessment of febrile seizures in children

Febrile seizures are the most common form of childhood seizures, affecting 2-5% of all children and usually appearing between 3 months and 5 years of age. Despite its predominantly benign nature, a febrile seizure (FS) is a terrifying experience for most parents. The condition is perhaps one of the most prevalent causes of admittance to pediatric emergency wards worldwide. FS, defined as either simple or complex, may be provoked by any febrile bacterial or (more usually) viral illness. No specific level of fever is required to diagnose FS. It is essential to exclude underlying meningitis in all children with FS, either clinically or, if any doubt remains, by lumbar puncture. There is no evidence, however, to support routine lumbar puncture in all children admitted with simple FS, especially when typical clinical signs of meningitis are lacking. The risk of epilepsy following FS is 1-6%. The association, however small, between FS and epilepsy may demonstrate a genetic link between FS and epilepsy rather than a cause and effect relationship. The effectiveness of prophylactic treatment with medication remains controversial. There is no evidence of the effectiveness of antipyretics in preventing future FS. Prophylactic use of paracetamol, ibuprofen or a combination of both in FS, is thus a questionable practice. There is reason to believe that children who have experienced a simple FS are over-investigated and over-treated. This review aims to provide physicians with adequate knowledge to make rational assessments of children with febrile seizures.

Autosomal dominant epilepsy with febrile seizures plus with missense mutations of the (Na+)-channel alpha 1 subunit gene, SCN1A

Evidence that febrile seizures have a strong genetic predisposition has been well documented. In families of probands with multiple febrile convulsions, an autosomal dominant inheritance with reduced penetrance is suspected. Four candidate loci for febrile seizures have been suggested to date; FEB1 on 8q13-q21, FEB2 on 19p, FEB3 on 2q23-q24, and FEB4 on 5q14-15. A missense mutation was identified in the voltage-gated sodium (Na(+))-channel beta 1 subunit gene, SCN1B at chromosome 19p13.1 in generalized epilepsy with the febrile seizures plus type 1 (GEFS+1) family. Several missense mutations of the (Na(+))-channel alpha 1 subunit (Nav1.1) gene, SCN1A were also identified in GEFS+2 families at chromosome 2q23-q24.3. The aim of this report is precisely to describe the phenotypes of Japanese patients with novel SCN1A mutations and to reevaluate the entity of GEFS+. Four family members over three generations and one isolated (phenotypically sporadic) case with SCN1A mutations were clinically investigated. The common seizure type in these patients was febrile and afebrile generalized tonic-clonic seizures (FS+). In addition to FS+, partial epilepsy phenotypes were suspected in all affected family members and electroencephalographically confirmed in three patients of two families. GEFS+ is genetically and clinically heterogeneous, and associated with generalized epilepsy and partial epilepsy as well. The spectrum of GEFS+ should be expanded to include partial epilepsies and better to be termed autosomal dominant epilepsy with febrile seizures plus (ADEFS+).

Hot water epilepsy: clinical and electrophysiologic findings based on 21 cases

PURPOSE

Our aim is to outline the clinical and electroencephalographic (EEG) features of patients with hot water epilepsy (HWE), a rare and unique form of reflex epilepsy.

METHODS

Twenty-one patients with HWE, seen in our clinic until 1999, were studied. Male outnumbered female subjects in a ratio of 3:1. The age at the onset of seizures ranged from 19 months to 27 years (mean age at onset, 12 years).

RESULTS

The main factors precipitating seizures were bathing with hot water and/or pouring water over the head. Six patients reported self-induction, either by increasing the heat or the amount of water and/or recalling earlier bathing experiences. Nine patients expressed feeling pleasure during the seizures. Twenty patients had partial seizures, eight of whom also had secondarily generalized seizures. One patient had apparent generalized seizures only. Spontaneous seizures were present in 62% of the cases. Interictal epileptogenic abnormalities were documented in the EEGs of eight patients; the other eight had normal EEGs. The major sites of epileptogenic activity were over the unilateral temporal regions (in 40% of patients). Neuroimaging studies available for 12 patients (four cranial computed tomography and eight cranial magnetic resonance imaging scans) revealed normal findings. Seizure control in patients who were followed up was achieved by reducing the temperature or the duration of the bath or shower; several of the patients required medication.

CONCLUSIONS

The major findings of this study are that HWE has a male preponderance, can be self-induced, is often done for pleasure, has complex triggering factors, and shows temporally located abnormalities in the EEGs. Although HWE is generally known to be self-limited, antiepileptic drug treatment may sometimes be necessary to control seizures. Hot water epilepsy should be classified separately among the epileptic syndromes.

Children with focal sharp waves: clinical and genetic aspects

PURPOSE

To investigate the spectrum of clinical manifestations in children with benign focal sharp waves in the EEG to gain further insight into the genetic background of clinical and EEG symptomatology in a family study.

METHODS

All 147 children (134 with seizures, 13 without) met the following inclusion criteria: (a) at least one EEG with focal sharp waves characteristic of benign partial epilepsies, and (b) at least 1 sibling investigated by EEG. The families were questioned orally or in writing regarding the occurrence of seizures. Patients' records were evaluated by a standardized scheme.

RESULTS

The following types of seizures occurred: febrile convulsions (FC), afebrile generalized tonic-clonic seizures (GTCS), simple and (rarely) complex partial seizures; and rolandic seizures in the strict sense. Neonatal seizures were overrepresented (6%); there were no indications of lesional causes. FC occurred in 38 children (26%). As compared with unselected cases of FC, complex symptoms were overrepresented. Family data suggested a maternal preponderance in the transmission of FC liability. Affected relatives of FC probands manifested FC more often than did relatives of probands without FC. Families of 32 patients with typical rolandic seizures (24% of the 134 probands with seizures) showed no aggregation of rolandic epilepsy, but did show variable seizure types. In the entire sample, EEG investigations showed focal sharp waves in 11% of siblings aged 2-10 years. No relation existed between clinical symptomatology and sharp wave findings in siblings. In 66% of probands, the EEG disclosed generalized genetic patterns. Siblings with generalized spike-waves (sw) and/or theta rhythm had focal sharp waves more often than those without sw and/or theta rhythm.

CONCLUSIONS

The phenotypic expression of the genetic anomaly underlying focal sharp waves shows considerable variability. The clinical and EEG findings are in agreement with a multifactorial pathogenesis of epilepsies with "benign" focal epileptiform sharp waves.

Febrile seizures--treatment and outcome

Assessment of treatment strategies in febrile seizures should be based on short- and long-term outcomes, with and without acute, intermittent, or chronic medical intervention, as well as short- and long-term side effects. Febrile seizures are a benign condition with a normal neurological, motor, intellectual, and cognitive long-term outcome and have a low risk of later epilepsy in most cases. Even many complex febrile seizures have a benign outcome. Prophylaxis may or may not reduce the recurrence rate, but does not appear to improve the long-term outcome as compared to acute treatment of seizures in progress. All agree that chronic prophylaxis with anti-epileptic agents is justified only in highly selected cases, if at all. Treatment with benzodiazepines during febrile episodes appears to effectively reduce the recurrence rate, provided adequate doses are given and compliance problems minimized. A selective approach to intermittent diazepam prophylaxis seems rational, as the recurrence risk and response to treatment are highly variable. An attractive alternative is acute treatment at seizure onset with rectal diazepam in solution given by the parents at home in order to prevent prolonged recurrent seizures. This regimen has the potential of moving the first line of anti-convulsant defence close to the child. It appears to be effective, inexpensive, feasible even for non-professionals, has few side effects and is well accepted by the parents. A reasonable policy would be to treat simple febrile seizures solely with acute rectal diazepam in solution and reserve intermittent diazepam prophylaxis for selected cases including those with multiple or prolonged recurrences, several risk factors for recurrent febrile seizures and other special situations.