Interictal sleep recordings during presurgical evaluation: Bidirectional perspectives on sleep related network functioning.

Sleep recordings are an integral part of presurgical evaluation in drug-resistant focal epilepsy. Physiological network functioning is substantially different between wakefulness and sleep and thus may add further complexity to the task of determining the epileptogenic zone (EZ). A thorough understanding of changes in epileptic networks in relation to sleep is therefore essential in order to fully appreciate the added value of sleep recordings. Furthermore, shared expertise in epilepsy and sleep is beneficial for both domains, as intracerebral EEG during presurgical evaluation offers a unique window into physiological networks and their interaction during sleep. This review intends to delineate the way in which sleep modifies interictal epileptic discharges (IEDs), and to summarize which sleep state is the most appropriate for aiding in discerning the EZ. Two approaches will be reviewed. First, classical scalp electroencephalography (EEG) recordings help to localize the EZ, especially during rapid-eye-movement (REM) sleep. REM sleep tends to narrow the field size of IEDs, and thus helps to target the core of the EZ. Second, automated analysis of intracerebral recordings can make use of both IEDs and sleep-related oscillations in combination. Notably, high frequency oscillations and directed connectivity measures can be assessed in a single sleep cycle and are valuable tools to probe epileptogenicity. In this approach, which exploits increased network interactions during sleep, non-REM-sleep is the most suitable sleep stage to extract multiple features of local and distributed neuronal activity in order to predict the EZ. The added value of intracerebral recordings is perfectly bidirectional. From a sleep perspective, invasive EEG recordings are a unique opportunity to unravel local sleep-related network function of superficial and deeply situated brain structures. Intracerebral EEG has thus allowed the dissection of sleep features and oscillations and their anatomical sources. A multicenter effort led by the Montreal Neurological Institute resulted in a detailed open-access atlas on normative EEG activity during sleep (https://mni-open-ieegatlas.research.mcgill.ca/). It contributed to our understanding that the human brain does not sleep uniformly but that specifically deep structures have distinct signatures that are discernable from the rest of the brain. Also, this research direction allowed us to gain insights into our understanding of the important neurocognitive functions of sleep. Finally, this review provides a clinical outlook on the benefit of genuine sleep recordings, i.e. recordings with additional sleep sensors, concomitant to presurgical evaluation, in order to fully discern common sleep disorders as a frequent comorbidity of epilepsy. In conclusion, shared expertise in sleep and epilepsy is of mutual added value for improving the management of patients with epilepsy.

Impact on quality of life in multiple sclerosis patients: Which urinary symptoms are to blame?

AIM: To evaluate the correlation between the Expanded Disability Status Scale (EDSS) in multiple sclerosis (MS) subjects, and the severity of lower urinary tract symptoms (LUTS), the bother caused by these symptoms and subjects' quality of life (QoL). MATERIAL AND METHODS: This cross-sectional study included 50 subjects with persistent LUTS secondary to MS who were recruited from the registry of a national NGO, between October 2017 and November 2019. Subjects with a history of any disease besides MS that could otherwise explain the presence of LUTS, as well as those with other neurological conditions were excluded. Information including MS duration, subjects' EDSS, voiding and storage LUTS, voiding symptoms' subscore of the International Prostate Symptom Score (IPSS-V), Overactive Bladder Symptom Scores (OABSS), Urinary Bothersome Questionnaire in Multiple Sclerosis (UBQMS), and urologic QoL (SF-Qualiveen) was gathered. Correlations between these scores were assessed using Spearman's bivariate correlations. Wilcoxon's signed rank test was used to evaluate the difference of impact between voiding and storage LUTS on bother of subjects. RESULTS: The median disease duration was 7±5.8years and the predominant lower urinary symptom was urgency (82%). Median OABSS and IPSS-V were respectively 8±3.8 and 8±3. Subjects were significantly more bothered from storage than voiding symptoms (2 vs. 1.6; P=0.03), and their QoL was directly affected by storage LUTS. Urgency urinary incontinence had the highest positive correlation with SFQ (r=0.542; P<0.01). MS duration and urologic QoL measured by SF-Q were negatively correlated (r=-0.345; P=0.01). CONCLUSION: In MS patients with LUTS, urologic QoL is mainly affected by storage urinary symptoms. Physicians should use a holistic approach to reduce the risk of complications in these patients, by controlling both voiding and storage symptoms, in particular urgency urinary incontinence that mostly affects patient's QoL.

Restless legs syndrome among multiple sclerosis patients in Lebanon.

BACKGROUND: Multiple sclerosis (MS) is often associated with fatigue, with an increased prevalence of sleep disorders compared to the general population, notably restless legs syndrome (RLS). The aim of this study was to evaluate the prevalence and severity of RLS as well the co-occurrence of spinal demyelination lesions in patients with MS in Lebanon. METHODS: In this cross-sectional study, we consulted the MS database of the Lebanese association against Multiple Sclerosis and sent out questionnaires to 300 MS patients to screen then confirm the presence of RLS. The final sample included 28 MS participants with confirmed RLS. We conducted further questionnaires to collect demographic data, screen for comorbidities, gather spinal MRI results, and evaluate the severity of both diseases (using the EDSS and the JHRLSS). RESULTS: Prevalence of RLS was 15% among MS patients in our study. 46.4% of RLS-affected MS patients had spinal cord demyelination lesions on their MRIs. Participants with MRI lesions had a lower severity score on the JHRLSS (p = 0.088). No association was found between the EDSS results and JHRLSS, demographic data, or comorbidities. CONCLUSION: Restless legs syndrome is commonly found among patients with multiple sclerosis in Lebanon, is underdiagnosed, and ought to be systematically evaluated for in order to improve the patients' quality of life.

The genome-wide landscape of DNA methylation and hydroxymethylation in response to sleep deprivation impacts on synaptic plasticity genes.

Sleep is critical for normal brain function and mental health. However, the molecular mechanisms mediating the impact of sleep loss on both cognition and the sleep electroencephalogram remain mostly unknown. Acute sleep loss impacts brain gene expression broadly. These data contributed to current hypotheses regarding the role for sleep in metabolism, synaptic plasticity and neuroprotection. These changes in gene expression likely underlie increased sleep intensity following sleep deprivation (SD). Here we tested the hypothesis that epigenetic mechanisms coordinate the gene expression response driven by SD. We found that SD altered the cortical genome-wide distribution of two major epigenetic marks: DNA methylation and hydroxymethylation. DNA methylation differences were enriched in gene pathways involved in neuritogenesis and synaptic plasticity, whereas large changes (>4000 sites) in hydroxymethylation where observed in genes linked to cytoskeleton, signaling and neurotransmission, which closely matches SD-dependent changes in the transcriptome. Moreover, this epigenetic remodeling applied to elements previously linked to sleep need (for example, Arc and Egr1) and synaptic partners of Neuroligin-1 (Nlgn1; for example, Dlg4, Nrxn1 and Nlgn3), which we recently identified as a regulator of sleep intensity following SD. We show here that Nlgn1 mutant mice display an enhanced slow-wave slope during non-rapid eye movement sleep following SD but this mutation does not affect SD-dependent changes in gene expression, suggesting that the Nlgn pathway acts downstream to mechanisms triggering gene expression changes in SD. These data reveal that acute SD reprograms the epigenetic landscape, providing a unique molecular route by which sleep can impact brain function and health.

K-complex-induced seizures in autosomal dominant nocturnal frontal lobe epilepsy.

OBJECTIVE: To examine in detail the relations between seizures and K-complexes in autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). METHODS: Prolonged continuous video-EEG recording and analysis of 30 seizures in an 18-year-old woman suffering from ADNFLE with a CHRNA4 gene mutation. RESULTS: Twenty-seven of 30 recorded seizures started just after a K-complex. In nine cases a sound induced a K-complex that was immediately followed by the seizure. Most seizures preceded repetitive and brief ictal restarts. CONCLUSIONS: Three new characteristics have been observed in this ADNFLE patient: a K-complex is almost invariably present at seizure onset; sounds trigger some seizures; ictal restarts occur often. SIGNIFICANCE: These new observations--the presence of K-complexes at seizure onset and occurrence of sound-triggered seizures--support the view that ADNFLE seizures may be initiated by K-complexes.