Subacute neocortical stimulation (SNCS) and its effects on epileptic activity in adults and children diagnosed with focal cortical dysplasia (FCD).

BACKGROUND: Chronic intracranial electrical stimulation is now widely used as treatment for drug resistant epilepsy. Subacute neocortical stimulation (SNCS) can also be performed during EEG recordings with intracranial electrodes (iEEG), but its diagnostic value remains largely unknown. METHODS: We assessed the effects of SNCS on the frequency of seizures and epileptiform discharges (EDs) during 290 h of iEEG- from 12 patients (6 adults, 6 children) with epilepsy secondary to focal cortical dysplasia (FCD). RESULTS: In 9/12 patients, SNCS periods showed decreased seizure-frequency (Median -73 %, p = 0.0093). At baseline, incidence of EDs were correlated with seizure-frequency (Spearman r = 0.59). However, this correlation disappeared during SNCS and a significant change in the incidence of EDs was observed. In addition, there was a trend towards greater reduction in seizure-frequency during SNCS in patients who underwent surgery. CONCLUSION: In summary, SNCS can reduce seizure-frequency and changes ED-frequency. The variability in ED changes may be explained by different effects of SNCS depending on electrode location. The magnitude of seizure reduction during SNCS suggests that this technique could contribute to preoperative assessment in epilepsy surgery.

Risk factors for reading disability in families with rolandic epilepsy.

OBJECTIVE: The high prevalence and impact of neurodevelopmental comorbidities in childhood epilepsy are now well known, as are the increased risks and familial aggregation of reading disability (RD) and speech sound disorder (SSD) in rolandic epilepsy (RE). The risk factors for RD in the general population include male sex, SSD, and ADHD, but it is not known if these are the same in RE or whether there is a contributory role of seizure and treatment-related variables. METHODS: An observational study of 108 probands with RE (age range: 3.6-22 years) and their 159 siblings (age range: 1-29 years; 83 with EEG data) were singly ascertained in the US or UK through a proband affected by RE. We used a nested case-control design, multiple logistic regression, and generalized estimating equations to test the hypothesis of an association between RD and seizure variables or antiepileptic drug treatment in RE; we also assessed an association between EEG focal sharp waves and RD in siblings. RESULTS: Reading disability was reported in 42% of probands and 22% of siblings. Among probands, RD was strongly associated with a history of SSD (OR: 9.64, 95% CI: 2.45-37.21), ADHD symptoms (OR: 10.31, 95% CI: 2.15-49.44), and male sex (OR: 3.62, 95% CI: 1.11-11.75) but not with seizure or treatment variables. Among siblings, RD was independently associated only with SSD (OR: 4.30, 95% CI: 1.42-13.0) and not with the presence of interictal EEG focal sharp waves. SIGNIFICANCE: The principal risk factors for RD in RE are SSD, ADHD, and male sex, the same risk factors as for RD without epilepsy. Seizure or treatment variables do not appear to be important risk factors for RD in probands with RE, and there was no evidence to support interictal EEG focal sharp waves as a risk factor for RD in siblings. Future studies should focus on the precise neuropsychological characterization of RD in families with RE and on the effectiveness of standard oral-language and reading interventions.