DNA methylation-based classification of malformations of cortical development in the human brain.

Malformations of cortical development (MCD) comprise a broad spectrum of structural brain lesions frequently associated with epilepsy. Disease definition and diagnosis remain challenging and are often prone to arbitrary judgment. Molecular classification of histopathological entities may help rationalize the diagnostic process. We present a retrospective, multi-center analysis of genome-wide DNA methylation from human brain specimens obtained from epilepsy surgery using EPIC 850 K BeadChip arrays. A total of 308 samples were included in the study. In the reference cohort, 239 formalin-fixed and paraffin-embedded (FFPE) tissue samples were histopathologically classified as MCD, including 12 major subtype pathologies. They were compared to 15 FFPE samples from surgical non-MCD cortices and 11 FFPE samples from post-mortem non-epilepsy controls. We applied three different statistical approaches to decipher the DNA methylation pattern of histopathological MCD entities, i.e., pairwise comparison, machine learning, and deep learning algorithms. Our deep learning model, which represented a shallow neuronal network, achieved the highest level of accuracy. A test cohort of 43 independent surgical samples from different epilepsy centers was used to test the precision of our DNA methylation-based MCD classifier. All samples from the test cohort were accurately assigned to their disease classes by the algorithm. These data demonstrate DNA methylation-based MCD classification suitability across major histopathological entities amenable to epilepsy surgery and age groups and will help establish an integrated diagnostic classification scheme for epilepsy-associated MCD.

Early clinical experience with lacosamide as adjunctive therapy in patients with refractory focal epilepsy and nocturnal seizures.

This retrospective study reports the early experience with lacosamide (LCM) as adjunctive therapy in Spanish patients with refractory focal epilepsy. Sixty patients (mean age 38.3 years, 54% women, mean epilepsy duration 27.2 years, mean seizure rate 9.7/month, and 28% with mainly nocturnal seizures) taking ≥2 antiepileptic drugs (mean 2.2) were included. LCM maintenance doses were 200, 300, 400, and 500mg/day in 31, 16, 10, and 3 patients, respectively. Patients were followed up for 13-24 months. Twenty-eight patients (47%) reported a ≥50% reduction in seizure frequency. A ≥50% reduction in seizure frequency was reported by 65% and 40% of patients in the nocturnal seizure and diurnal seizure subgroups, respectively (p>0.05). Of the 28 responders, 2 achieved stable periods of seizure freedom of 6 and 11 months after starting LCM. Twenty patients (33%) reported drug-related adverse events (AEs); the most common was dizziness (16 patients). LCM was withdrawn in 8 patients (13%). There were no serious AEs. These results support the efficacy and safety of adjunctive LCM in patients with partial-onset seizures.