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Aim: To determine the incidence of mTOR pathway variants in surgical malformations of cortical development (MCDs) and negative histology cases. To assess the predictive value of genotype-histotype findings on the surgical outcome. Methods: We enrolled surgically treated patients from Niguarda and Bellaria Hospital. We retrospectively selected all cases operated on from 2013 to 2016 with type II focal cortical dysplasia (FCD) and unmatched formalin-fixed, paraffin-embedded (FFPE) brain tissues available. For the prospective phase, we selected patients with neuropathological diagnosis of MCDs or aspecific findings and fresh frozen brain tissues. We performed smMIPs analysis to target MTOR (retrospective cases) and 9 mTOR pathway genes (prospective cases). We performed genotype-histotype and surgical outcome statistical correlations. Results: Seven pathogenic MTOR somatic variants were found in FFPE brain tissues of 28 retrospective cases. We prospectively selected 63 MCDs and negative histology cases out of 184 cases. Six MTOR somatic variants and two DEPDC5, two TSC1 and one TSC2 germline variants were identified. Type IIb FCD was associated with MTOR genotype (P< 0.001). Any differences in surgical outcome between MTOR mutated-not mutated cases were found. A MTOR patient repeated surgeries up to hemispherectomy without seizure control and with a shift of the epileptogenic zone into the residual “normal” hemisphere. All patients carrying germline variants except one (TSC1) were seizure-free after surgery. Conclusion: a genetic aetiology is found in 18 patients: 13 brain somatic MTOR (14%), 2 DEPDC5 (3.2%), 2 TSC1 (3.2%) and 1 TSC2 (1.6%) germline variants. Somatic MTOR variants are found at low-level somatic mosaicism especially in type IIb FCDs. MTOR genotype does not represent a contraindication for epilepsy surgery. Nevertheless, the detection of MTOR somatic mutation and the failure in seizure control after the first surgery may represent a red flag for planning further surgical procedures.

Veronica Menghi,1 Francesca Bisulli,2 Paolo Tinuper,2 Lino Nobili3,4 1Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy; 2IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy; 3“Claudio Munari” Center for Epilepsy Surgery, Niguarda Hospital, Milan, Italy; 4Department of Neuroscience (DINOGMI), IRCCS, Giannina Gaslini Institute, University of Genoa, Genoa, Italy Abstract: Sleep-related hypermotor epilepsy (SHE), previously called nocturnal frontal lobe epilepsy (NFLE), is a focal epilepsy characterized by asymmetric tonic/dystonic posturing and/or complex hyperkinetic seizures occurring mostly during sleep. SHE fulfills the definition of rare disease with an estimated minimum prevalence of 1.8/100,000 individuals, and it represents about 10% of drug-resistant surgical cases. Although SHE and autosomal-dominant SHE (ADSHE) have been considered benign epileptic conditions for a long time, emerging data have shed light on the severity of this disorder and some peculiar features can impact negatively on the quality of life of SHE patients. In fact, seizure frequency can be very high, resulting in nocturnal sleep fragmentation with possible diurnal consequences such as excessive sleepiness and fatigue. Moreover, recent studies, adopting a systematic neuropsychological assessment, have shown deficits in memory, executive functions and visuo-spatial abilities in almost half of SHE patients. Intellectual disabilities and psychiatric disorders have also been reported in some genetic forms. SHE may also exert a negative effect on health-related quality of life, especially in domains pertaining to a patient’s role in the family, social context and patient’s illness experience. Despite a good response to pharmacological treatment, especially with carbamazepine, 30% of SHE patients suffer from drug-resistant seizures. Finally, recent studies suggest a poor prognosis in a high percentage of SHE patients with a 20.4% cumulative probability of achieving terminal remission at 10 years from onset. For selected drug-resistant SHE patients, epilepsy surgery is the only treatment offering high probability of recovery, both for seizures and for epilepsy-related sleep alterations. Keywords: epilepsy, parasomnias, sleep-related hypermotor epilepsy, nocturnal frontal lobe epilepsy, epidemiology

Veronica Menghi,1 Francesca Bisulli,2 Paolo Tinuper,2 Lino Nobili3,4 1Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy; 2IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy; 3“Claudio Munari” Center for Epilepsy Surgery, Niguarda Hospital, Milan, Italy; 4Department of Neuroscience (DINOGMI), IRCCS, Giannina Gaslini Institute, University of Genoa, Genoa, Italy Abstract: Sleep-related hypermotor epilepsy (SHE), previously called nocturnal frontal lobe epilepsy (NFLE), is a focal epilepsy characterized by asymmetric tonic/dystonic posturing and/or complex hyperkinetic seizures occurring mostly during sleep. SHE fulfills the definition of rare disease with an estimated minimum prevalence of 1.8/100,000 individuals, and it represents about 10% of drug-resistant surgical cases. Although SHE and autosomal-dominant SHE (ADSHE) have been considered benign epileptic conditions for a long time, emerging data have shed light on the severity of this disorder and some peculiar features can impact negatively on the quality of life of SHE patients. In fact, seizure frequency can be very high, resulting in nocturnal sleep fragmentation with possible diurnal consequences such as excessive sleepiness and fatigue. Moreover, recent studies, adopting a systematic neuropsychological assessment, have shown deficits in memory, executive functions and visuo-spatial abilities in almost half of SHE patients. Intellectual disabilities and psychiatric disorders have also been reported in some genetic forms. SHE may also exert a negative effect on health-related quality of life, especially in domains pertaining to a patient’s role in the family, social context and patient’s illness experience. Despite a good response to pharmacological treatment, especially with carbamazepine, 30% of SHE patients suffer from drug-resistant seizures. Finally, recent studies suggest a poor prognosis in a high percentage of SHE patients with a 20.4% cumulative probability of achieving terminal remission at 10 years from onset. For selected drug-resistant SHE patients, epilepsy surgery is the only treatment offering high probability of recovery, both for seizures and for epilepsy-related sleep alterations. Keywords: epilepsy, parasomnias, sleep-related hypermotor epilepsy, nocturnal frontal lobe epilepsy, epidemiology

ObjectiveThe differential diagnosis between sleep-related hypermotor epilepsy (SHE) and disorders of arousal (DOA) may be challenging. We analyzed the stage and the relative time of occurrence of parasomnic and epileptic events to test their potential diagnostic accuracy as criteria to discriminate SHE from DOA.MethodsVideo-polysomnography recordings of 89 patients with a definite diagnosis of DOA (59) or SHE (30) were reviewed to define major or minor events and to analyze their stage and relative time of occurrence. The “event distribution index” was defined on the basis of the occurrence of events during the first versus the second part of sleep period time. A group analysis was performed between DOA and SHE patients to identify candidate predictors and to quantify their discriminative performance.ResultsThe total number of motor events (i.e. major and minor) was significantly lower in DOA (3.2 ± 2.4) than in SHE patients (6.9 ± 8.3; p = 0.03). Episodes occurred mostly during N3 and N2 in DOA and SHE patients, respectively. The occurrence of at least one major event outside N3 was highly suggestive for SHE (p = 2*e-13; accuracy = 0.898, sensitivity = 0.793, specificity = 0.949). The occurrence of at least one minor event during N3 was highly suggestive for DOA (p = 4*e-5; accuracy = 0.73, sensitivity = 0.733, specificity = 0.723). The “event distribution index” was statistically higher in DOA for total (p = 0.012) and major events (p = 0.0026).ConclusionThe stage and the relative time of occurrence of minor and major motor manifestations represent useful criteria to discriminate DOA from SHE episodes.

Objective: The aim of this study was to characterize the neuropsychological features of a representative sample of Sleep-related Hypermotor Epilepsy (SHE) patients and to highlight clinical associations. Methods: This cross-sectional study included 60 consecutive patients with video/video-electroencephalography–documented SHE. All were assessed by measures of intelligence. Individuals with normal scores underwent a standardized battery of tests. The Fisher exact test and Wilcoxon rank-sum test for statistical analysis. Results: Mean total IQ was 96.96 ± 21.50, with significant differences between verbal and performance scores (p < 0.0001). Nine patients (15%) had intellectual disability (ID)/cognitive deterioration. Of the 49 assessed by the extensive battery, 23 (46.9%) showed deficits in at least one test evaluating phonemic fluency (24.5%), memory (24.5%), inhibitory control (22.4%), or working memory (10.2%). Patients with mutations in SHE genes had lower IQ than patients without mutations, irrespective of the specific gene (p = 0.0176). Similarly, pathological neurological examination (NE) and “any underlying brain disorder” (at least one among pathological NE, abnormal brain magnetic resonance imaging findings, perinatal insult) were associated with ID (p = 0.029, p = 0.036). A higher seizure frequency at last assessment and poor prognosis correlated with worse scores in visuo-spatial memory (p = 0.038, p = 0.040) and visuo-spatial abilities (p = 0.016). Status epilepticus (p = 0.035), poor response to antiepileptic drugs (p = 0.033), and poor prognosis (p = 0.020) correlated with lower shifting abilities, whereas bilateral convulsive seizures correlated with worse working memory (p = 0.049). Conclusion: In all, 53.3% of SHE patients had neuropsychological deficits. The profile of impairment showed worse verbal IQ, as well as deficits in extrafrontal and selective frontal functions. Our data support the contribution of genetics in ID by different biological mechanisms. Variables of clinical severity affect memory and executive functioning.