Regional Differences in the Sensitivity of MEG for Interictal Spikes in Epilepsy

MEG interictal spikes as recorded in epilepsy patients are a reflection of intracranial interictal activity. This study investigates the relationship between the estimated sources of MEG spikes and the location, distribution and size of interictal spikes in the invasive ECoG of a group of 38 epilepsy patients that are monitored for pre-surgical evaluation. An amplitude/surface area measure is defined to quantify and rank ECoG spikes. It is found that all MEG spikes are associated with an ECoG spike that is among the three highest ranked in a patient. Among the different brain regions considered, the fronto-orbital, inter-hemispheric, tempero-lateral and central regions stand out. In an accompanying simulation study it is shown that for hypothesized extended sources of larger sizes, as suggested by the data, source location, orientation and curvature can partly explain the observed sensitivity of MEG for interictal spikes

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 RE probands (age range 3.6–22 years) and their 159 siblings (age range 1–29 years; 83 with EEG data) singly ascertained in the US or UK through an affected RE proband. We used a nested case-control design, multiple logistic regression and generalized estimating equations to test the hypothesis of 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: RD 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 RE probands, 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 characterisation of RD in RE families, and on the effectiveness of standard oral-language and reading interventions