Objective:To assess the long-term outcome of sleep-related hypermotor epilepsy (SHE).Methods:We retrospectively reconstructed a representative cohort of patients diagnosed with SHE according to international diagnostic criteria, sleep-related seizures ≥75% and follow-up ≥5 years. Terminal remission (TR) was defined as a period of ≥5 consecutive years of seizure freedom at the last follow-up. We used Kaplan-Meier estimates to calculate the cumulative time-dependent probability of TR and to generate survival curves. Univariate and multivariate Cox regression analyses were performed.Results:We included 139 patients with a 16-year median follow-up (2,414 person-years). The mean age at onset was 13 ± 10 years. SHE was sporadic in 86% of cases and familial in 14%; 16% of patients had underlying brain abnormalities. Forty-five percent of patients had at least 1 seizure in wakefulness lifetime and 55% had seizures only in sleep (typical SHE). At the last assessment, 31 patients achieved TR (TR group, 22.3%), while 108 (NTR group, 77.7%) still had seizures or had been in remission for <5 years. The cumulative TR rate was 20.4%, 23.5%, and 28.4% by 10, 20, and 30 years from inclusion. At univariate analysis, any underlying brain disorder (any combination of intellectual disability, perinatal insult, pathologic neurologic examination, and brain structural abnormalities) and seizures in wakefulness were more frequent among the NTR group (p = 0.028; p = 0.043). Absence of any underlying brain disorder (hazard ratio 4.21, 95% confidence interval 1.26–14.05, p = 0.020) and typical SHE (hazard ratio 2.76, 95% confidence interval 1.31–5.85, p = 0.008) were associated with TR.Conclusions:Our data show a poor prognosis of SHE after a long-term follow-up. Its outcome is primarily a function of the underlying etiology.

Objective To evaluate the role of sleep cyclic alternating pattern (CAP) in patients with isolated REM sleep behavior disorder (IRBD) and ascertain whether CAP metrics might represent a marker of phenoconversion to a defined neurodegenerative condition. Methods Sixty-seven IRBD patients were included and classified into patients who phenoconverted to a neurodegenerative disease (RBD converters: converter REM sleep behavior disorder [cRBD]; n = 34) and remained disease-free (RBD non-converters: non-converter REM sleep behavior disorder [ncRBD]; n = 33) having a similar follow-up duration. Fourteen age- and gender-balanced healthy controls were included for comparisons. Results Compared to controls, CAP rate and CAP index were significantly decreased in IRBD mainly due to a decrease of A1 phase subtypes (A1 index) despite an increase in duration of both CAP A and B phases. The cRBD group had significantly lower values of CAP rate and CAP index when compared with the ncRBD group and controls. A1 index was significantly reduced in both ncRBD and cRBD groups compared to controls. When compared to the ncRBD group, A3 index was significantly decreased in the cRBD group. The Kaplan-Meier curve applied to cRBD estimated that a value of CAP rate below 32.9% was related to an average risk of conversion of 9.2 years after baseline polysomnography. Conclusion IRBD is not exclusively a rapid eye movement (REM) sleep parasomnia, as non-rapid eye movement (non-REM) sleep microstructure can also be affected by CAP changes. Further studies are necessary to confirm that a reduction of specific CAP metrics is a marker of neurodegeneration in IRBD.

HighlightsWe assessed sudden unexpected death in epilepsy in nocturnal frontal lobe epilepsy.The incidence of SUDEP in NFLE was no higher than that of other epilepsy populations.The lower than expected risk of SUDEP might reflect a low occurrence of GTCS in NFLE.

Objective Incomplete hippocampal inversion (IHI) is a relatively frequent radiological finding at visual inspection in both epilepsy and healthy controls, but its clinical significance is unclear. Here, we systematically retrieve and assess the association between epilepsy and IHI using a meta‐analytic approach. Additionally, we estimate the prevalence of IHI in patients with malformation of cortical development (MCD). Methods We systematically searched two databases (Embase and PubMed) to identify potentially eligible studies from their inception to December 2019. For inclusion, studies were population‐based, case–control, observational studies reporting on epilepsy and IHI. The risk of developing epilepsy in IHI (estimated with odds ratio [ORs]) and the frequency of IHI among patients with MCD are provided. Results We screened 3601 records and assessed eligibility of 2812 full‐text articles. The final material included 13 studies involving 1630 subjects. Seven studies (1329 subjects: 952 epileptic and 377 nonepileptic) were included for the estimation of the risk of developing epilepsy in the presence of IHI. The estimated OR of active epilepsy in IHI was 1.699 (95% confidence interval = 0.880–3.281), with moderate heterogeneity across studies (I2 = 71%). Seven studies (591 patients) provided information about the frequency of IHI in MCD. Up to one third of patients with MCD (27.9%) presented coexistent IHI. Significance The present findings confirm that IHI is commonly observed in patients with MCD especially in periventricular nodular heterotopia or polymicrogyria. However, the estimated OR indicates overall weak increased odds of epilepsy in people with IHI, suggesting that the presence of isolated IHI cannot be considered a strong independent predictor for epilepsy development. Clear‐cut neuroradiological criteria for IHI and advanced postprocessing analyses on structural magnetic resonance imaging scans are recommended to highlight differences between epileptogenic and nonepileptogenic IHI.