Clinical and Electroencephalographic (EEG) Features Associated With Refractoriness in Benign Childhood Epilepsy With Centrotemporal Spikes

Phase Lag Analysis Scalp Electroencephalography May Predict Seizure Frequencies in Patients with Childhood Epilepsy with Centrotemporal Spikes

Background

Childhood epilepsy with centrotemporal spikes (CECTS) is the most common epilepsy syndrome in school-aged children. However, predictors for seizure frequency are yet to be clarified using the phase lag index (PLI) analyses. We investigated PLI of scalp electroencephalography data at onset to identify potential predictive markers for seizure times.

Methods

We compared the PLIs of 13 patients with CECTS and 13 age- and sex-matched healthy controls. For the PLI analysis, we used resting-state electroencephalography data (excluding paroxysmal discharges), and analyzed the mean PLIs among all electrodes and between interest electrodes (C3, C4, P3, P4, T3, and T4) and other electrodes. Furthermore, we compared PLIs between CECTS and control data and analyzed the associations between PLIs and total seizure times in CECTS patients.

Results

No differences were detected in clinical profiles or visual electroencephalography examinations between patients with CECTS and control participants. In patients with CECTS, the mean PLIs among all electrodes and toward interest electrodes were higher at the theta and alpha bands and lower at the delta and gamma bands than those in control participants. Additionally, the mean PLIs toward interest electrodes in the beta frequency band were negatively associated with seizure times (P = 0.02).

Conclusion

The resting-state delta, theta, alpha, and gamma band PLIs might reflect an aberrant brain network in patients with CECTS. The resting-state PLI among the selected electrodes of interest in the beta frequency band may be a predictive marker of seizure times in patients with CECTS.

Spike wave characteristics and temporal spike evolution on serial EEG in childhood epilepsy with centrotemporal spikes

PURPOSE

To assess the spike characteristics and temporal spike evolution on serial EEG of children with childhood epilepsy with centrotemporal spikes (CECTS) treated with anti-seizure medication.

METHODS

The study cohort consisted of 127 children with CECTS divided into three groups based on anti-seizure medication responsiveness: group I: seizure-free with monotherapy (n: 61, 48%), group II: seizure-controlled with monotherapy (n: 52, 41%) and group III: seizure-controlled with dual therapy (n: 14, 11%). The clinical profiles and sequential four-year follow-up visual EEG recordings of the children were evaluated. Each EEG was reanalyzed with three spike characteristics on the epochs: (1) spike-wave rate, (2) spike topography, and (3) spike localization. We calculated the spike clearance velocity, which is defined as a decrease in the spike-wave rate over time in four-year sequential follow-up EEGs.

RESULTS

There was no statistical significance across the study groups with respect to initial EEG spike characteristics (spike-wave rate, spike localization, and spike topography). Seizure recurrence occurred in 15 patients (12.8%) who discontinued anti-seizure medication. There was no statistically significant difference between the spike characteristics on EEG just before the discontinuation of anti-seizure medication and seizure recurrence. However, the spike clearance velocity was significantly slower in group III than in group I in four-year sequential follow-up EEGs (p = 0.002). A statistically significant decrease in the mean spike-wave rate was observed in group I in the first year of anti-seizure medication (p<0.001). The spike clearance velocity was also more prominent during the second year of treatment in group II and the third year of treatment in group III. However, the spike clearance velocity was not different across the anti-seizure medication groups (oxcarbazepine, valproic acid, and levetiracetam).

CONCLUSION

Spike clearance velocity might be a valuable EEG marker to guide anti-seizure medication in children with CECTS.

Clinical Features at the Time of Diagnosis of Benign Epilepsy With Centrotemporal Spikes Do Not Predict Subsequent Seizures

BACKGROUND

Benign epilepsy with centrotemporal spikes (BECTs) usually follows a self-limited course, with a single or few seizures. Assessing the likelihood of a second seizure after the first event may help establishing the need for antiepileptic drug therapy at the time of diagnosis. We aimed at identifying clinical and/or electrographic features that could predict the occurrence of a second seizure.

METHODS

We reviewed the clinical and electroencephalographic (EEG) data of children diagnosed with BECTs between 2006 and 2012. Demographic, clinical, routine, and sleep-deprived EEG findings were analyzed.

FINDINGS

Seventy-three patients were reviewed who had been followed for four to 10 years. Age at first seizure ranged between three and 16 years (median nine years). In 28 children the first seizure occurred after 10 years age. Ten children were aged three to six years. EEG data were available for 64 individuals. No specific clinical features or seizure semiology were predictive of a second seizure. Neither the type nor the location of interictal EEG discharges was indicative of a second seizure. Among children whose EEG records depicted sleep-related enhancement of interictal discharges, 58.8% sustained a second seizure. This finding did not reach statistical significance. Forty children sustained a second seizure, mostly within 12 months in 30 (P < 0.0001). Among these 30 children, the second event occurred after a median period of 156 days, compared with 654 days for cases with a second seizure after 12 months.

CONCLUSIONS

Neither clinical features, seizure characteristics, nor routine EEG findings were effective in predicting the likelihood of a second seizure in children with BECTs.

Nightly oral administration of topiramate for benign childhood epilepsy with centrotemporal spikes

OBJECTIVE

The objective of this study was to explore the feasibility of nightly oral administration of topiramate for treating benign childhood epilepsy with centrotemporal spikes (BECTS).

METHODS

Eighty-five children with BECTS receiving topiramate treatment were randomly divided into A group (44 patients) and B group (41 patients). In A group, topiramate was orally administrated once a night, with a final dose of 2 mg/kg/day. In B group, topiramate was orally administrated twice a day, with a final dose of 4 mg/kg/day. At the end of the 12-month follow-up period, clinical efficacy, changes in electroencephalographic (EEG) activity, and adverse reactions were analyzed.

RESULTS

There was no significant difference in overall efficacy rate, percentages of patients achieving seizure free, or changes in EEG activity between the two groups (P > 0.05). The rate of adverse reactions for A group was 9.1 %, which was significantly lower than the 29.3 % for B group (χ (2) = 4.262, P < 0.05).

CONCLUSION

Nightly oral administration of topiramate is a feasible strategy for the treatment of BECTS, with the advantages of comparable efficacy, convenience, and fewer adverse reactions.