Spike persistence and normalization in benign epilepsy with centrotemporal spikes - Implications for management

The fate of spikes in self-limited epilepsy with centrotemporal spikes: Are clinical and baseline EEG features effective?

OBJECTIVE

The aim of this study is to evaluate the effects of clinical and electroencephalographic features on spike reduction with a focus on the first EEG characteristics in self-limited epilepsy with centrotemporal spikes (SeLECTS).

METHODS

This retrospective study was conducted on SeLECTS patients of with at least five years follow-up and at least two EEG recordings in which spike wave indexes (SWI) were calculated.

RESULTS

136 patients were enrolled. Median SWI in the first and last EEGs were 39% (7.6-89%) and 0 (0-112%). Gender, seizure onset age, psychiatric diseases, seizure characteristics (semiology, duration, and relationship to sleep), last EEG time, and spike lateralization in the first EEG did not have a statistically significant effect on the SWI change. Multinomial logistic regression analysis revealed that presence of phase reversal, interhemispheric generalization, and SWI percentage had a significant effect on spike reduction. The frequency of seizures was also significantly decreased in patients with a greater decrease in SWI. Both valproate and levetiracetam were statistically superior in suppressing SWI, with no significant difference between them.

CONCLUSION

Interhemispheric generalization and phase reversal in the first EEG in SeLECTS had negative effects on the spike reduction. The most effective ASMs in reducing spikes were valproate and levetiracetam.

Anti-Seizure Medication Treatment of Benign Childhood Epilepsy With Centrotemporal Spikes: A Systematic Review and Meta-analysis

Background: This study aimed to evaluate the efficacy and tolerability of Anti-Seizure medication (ASM) treatment in patients with BECTS. Method: We searched PubMed, Cochrane Library, Embase, MEDLINE, Web of Science, China National Knowledge Infrastructure (CNKI), WANFANG DATA, and China Science and Technology Journal Database (VIP) between 1 Jan 1990, and 1 Sep 2021, for randomized controlled studies. Data on seizure freedom rate, rate of treatment withdrawal due to serious adverse events, rate of any adverse events and dropout, 50% remission rate, the proportion of patients whose EEG to be normalized, and improvement in cognitive function were extracted by two authors independently. The pooled data were meta-analyzed using a random effects model. Results: A total of 27 studies evaluating 9 ASMs were included, 19 of which were suitable for meta-analysis. Compared with sulthiame (STM), levetiracetam (LEV) was associated with a higher probability of treatment withdrawal due to serious adverse events [RR = 5.12, 95% CI (1.19, 22.01), I ² = 0.0%], experiencing any adverse events [RR = 5.12, 95% CI (1.19, 22.01)], and dropping out for any reason [RR = 3.17, 95% CI (1.36, 10.11)], while it did not affect the seizure freedom rate [RR = 0.90, 95% CI (0.75, 1.06)]. LEV significantly improved cognitive performance relative to carbamazepine (CBZ) but had no effect on the proportion of any adverse events [RR = 0.62, 95% CI (0.25, 1.59)] and EEG to be normalized [RR = 1.27, 95% CI (0.94, 1.71)]. There was no higher probability of a 50% remission rate when comparing valproic acid (VPA) to LEV [RR = 0.96, 95% CI (0.57, 1.61)] and oxcarbazepine (OXC) [RR = 0.61, 95% CI (0.31, 1.20)]. In addition, STM was related to a higher probability of EEG normalization than placebo [RR = 4.61, 95% CI (2.12, 10.01)]. The included single studies also provided some evidence for the efficacy and/or tolerability of other ASMs in BECTS, including topiramate, lamotrigine, clobazam, and clonazepam. The risk of bias of the included studies was frequently low or unclear. Conclusion: This study indicated some discrepancies in efficacy and tolerability among ASMs used in patients with BECTS. More randomized controlled trials (RCTs) comparing ASMs with larger populations are required to ascertain the optimum antiepileptic drug treatment to guide clinicians.

A Self-Limited Childhood Epilepsy as Co-Incidental in Cerebral Palsy

Background

Cerebral palsy is the most frequent motor disability in childhood and is associated with a higher incidence of seizure disorders. In many instances, it is recognized that motor difficulties, as well as seizures, are from the same underlying brain lesion. However, self-limited childhood epilepsies, being a common group of epilepsy syndromes, would be expected to occur in patients with cerebral palsy merely on chance association and be unrelated to the structural brain imaging abnormality causing the motor impairment. Differential diagnosis in this case is important determining the long-term prognosis and need for anticonvulsant treatment.

Case Presentation

Here, we report two patients with cerebral palsy combined with epilepsy, whose age at onset, seizure semiology and electroclinical features were similar to children with self-limited childhood-specific seizure disorders (childhood epilepsy with centrotemporal spikes and Panayiotopoulos syndrome).

Conclusion

These cases highlight the importance of comprehensive differential diagnosis of seizures in cerebral palsy. Co-existence of age-dependent focal epilepsies with an underlying brain pathology as white matter injury, not affecting the cerebral cortex, might take place in the case of children with impaired motor skills. With health systems increasingly utilizing clinical pathways, it is important to consider the possibility of a self-limited childhood epilepsy and avoid aggressive and unnecessary medication treatment in children with cerebral palsy.

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.

Outcome analysis of children with rolandic discharges on EEG: A real-world study

OBJECTIVE

To evaluate the efficacy of drugs for patients with central mid-temporal (rolandic) discharges detected by electroencephalogram (EEG).

METHODS

This retrospective study enrolled 430 patients with rolandic discharges, who were treated at the Neuroelectrophysiology Center of the Children's Hospital of Nanjing Medical University from February 2015 to February 2018. Patients were divided into three groups according to medication: levetiracetam (LEV), oxcarbazepine (OXC) and sodium valproate (VPA). All patients were followed up for at least 2 years, and the seizure frequency, EEG results and side effects of drugs were recorded.

RESULTS

Rolandic epilepsy (RE) occurred in 398/430 patients. Rolandic discharges were also found in those with febrile seizures, tic disorders, and attention deficit hyperactivity disorder. Thirty-one patients experienced only one seizure and no relapse, while 367 patients experienced more than two seizures (including 364 receiving drug treatment). The failure rate of LEV as initial therapy was significantly higher than those of OXC and VPA. The overall efficacy of OXC was higher than that of LEV. However, none of the three medications could control rolandic discharges. Moreover, the side effects of the three drugs were mild.

CONCLUSIONS

Rolandic discharges are common in children with RE and other diseases, such as febrile seizures, tic disorders, and attention deficit hyperactivity disorder. Patients with only one seizure need no treatment. Those with multiple seizures can be treated with OXC, LEV, and VPA. OXC serves as the initial antiepileptic drug with a lower failure rate and significant efficacy.

Change of centrotemporal spikes from onset to remission in self-limited epilepsy with centrotemporal spikes (SLECTS)

OBJECTIVE

To reveal the changes of centrotemporal spikes that occur during the disease course of self-limited epilepsy with centrotemporal spikes (SLECTS).

METHOD

We retrospectively reviewed the serial EEGs of 63 patients with SLECTS from initial diagnosis to remission. There were 32 patients who did not undergo treatment and 31 patients who underwent treatment with oxcarbazepine (OXC). The change of occurrence or abundance, voltage, and location of centrotemporal spikes of serial EEGs were analyzed and compared between the two groups. Clinical seizure evidenced and reported was counted. The time gap between seizure remission and EEG remission was measured in the two groups.

RESULT

Changes of occurrence or abundance of the centrotemporal spikes were either abrupt (sudden disappearance of the frequent spikes on following EEG) or gradual (decline in number over 2 or more serial EEGs). Pattern of spike disappearance was not significantly different between the medication naïve group and OXC treated group. The spike voltage or the location of centrotemporal spikes did not change during the disease course in most cases. Delay between seizure remission and EEG normalization was 3.34 ± 1.75 (mean ± standard deviation, range: 0.77-7.97) years in untreated patients and 3.03 ± 1.41 (0.95-6.61) years in OXC-treated group.

CONCLUSION

Pattern of spike disappearance in SLECTS was either abrupt or gradual. Treatment with OXC had no effect in the disappearance pattern. Precise data regarding the pattern of disappearance and delay between seizure remission and EEG normalization can help to understand the evolution of spike in SLECTS and to predict the timing of normalization of EEG after seizure remission.

Electroencephalographic Resting-State Functional Connectivity of Benign Epilepsy with Centrotemporal Spikes

Background and Purpose

We aimed to reveal resting-state functional connectivity characteristics based on the spike-free waking electroencephalogram (EEG) of benign epilepsy with centrotemporal spikes (BECTS) patients, which usually appears normal in routine visual inspection.

Methods

Thirty BECTS patients and 30 disease-free and age- and sex-matched controls were included. Eight-second EEG epochs without artifacts were sampled and then bandpass filtered into the delta, theta, lower alpha, upper alpha, and beta bands to construct the association matrix. The weighted phase lag index (wPLI) was used as an association measure for EEG signals. The band-specific connectivity, which was represented as a matrix of wPLI values of all edges, was compared for analyzing the connectivity itself. The global wPLI, characteristic path length (CPL), and mean clustering coefficient were compared.

Results

The resting-state functional connectivity itself and the network topology differed in the BECTS patients. For the lower-alpha-band and beta-band connectivity, edges that showed significant differences had consistently lower wPLI values compared to the disease-free controls. The global wPLI value was significantly lower for BECTS patients than for the controls in lower-alpha-band connectivity (mean±SD; 0.241±0.034 vs. 0.276±0.054, p=0.024), while the CPL was significantly longer for BECTS in the same frequency band (mean±SD; 4.379±0.574 vs. 3.904±0.695, p=0.04). The resting-state functional connectivity of BECTS showed decreased connectivity, integration, and efficiency compared to controls.

Conclusions

The connectivity differed significantly between BECTS patients and disease-free controls. In BECTS, global connectivity was significantly decreased and the resting-state functional connectivity showed lower efficiency in the lower alpha band.

Beta oscillations in the sensorimotor cortex correlate with disease and remission in benign epilepsy with centrotemporal spikes

INTRODUCTION

Benign epilepsy with centrotemporal spikes (BECTS) is a common form of childhood epilepsy with the majority of those afflicted remitting during their early teenage years. Seizures arise from the lower half of the sensorimotor cortex of the brain (e.g. seizure onset zone) and the abnormal epileptiform discharges observed increase during NREM sleep. To date no clinical factors reliably predict disease course, making determination of ongoing seizure risk a significant challenge. Prior work in BECTS have shown abnormalities in beta band (14.9-30 Hz) oscillations during movement and rest. Oscillations in this frequency band are modulated by state of consciousness and thought to reflect intrinsic inhibitory mechanisms.

METHODS

We used high density EEG and source localization techniques to examine beta band activity in the seizure onset zone (sensorimotor cortex) in a prospective cohort of children with BECTS and healthy controls during sleep. We hypothesized that beta power in the sensorimotor cortex would be different between patients and healthy controls, and that beta abnormalities would improve with resolution of disease in this self-limited epilepsy syndrome. We further explored the specificity of our findings and correlation with clinical features. Statistical testing was performed using logistic and standard linear regression models.

RESULTS

We found that beta band power in the seizure onset zone is different between healthy controls and BECTS patients. We also found that a longer duration of time spent seizure-free (corresponding to disease remission) correlates with lower beta power in the seizure onset zone. Exploratory spatial analysis suggests this effect is not restricted to the sensorimotor cortex. Exploratory frequency analysis suggests that this phenomenon is also observed in alpha and gamma range activity. We found no relationship between beta power and the presence or rate of epileptiform discharges in the sensorimotor cortex or a test of sensorimotor performance.

CONCLUSION

These results provide evidence that cortical beta power in the seizure onset zone may provide a dynamic physiological biomarker of disease in BECTS.