Co-activation of rhythms during alpha band oscillations as an interictal biomarker of exploding head syndrome.

BACKGROUND: Exploding head syndrome is a rarely reported benign sensory parasomnia that may nonetheless have significant impact on patients' quality of life and their perceived well-being. To date, the mechanisms underlying attacks, characterised by a painless perception of abrupt, loud noises at transitional sleep-wake or wake-sleep states, are by and large unclear. METHODS AND RESULTS: In order to address the current gap in the knowledge of potential underlying pathophysiology, a retrospective case-control study of polysomnographic recordings of patients presenting to a tertiary sleep disorders clinic with exploding head syndrome was conducted. Interictal (non-attack associated) electroencephalographic biomarkers were investigated by performing macrostructural and event-related dynamic spectral analyses of the whole-night EEG. In patients with exploding head syndrome, additional oscillatory activity was recorded during wakefulness and at sleep/wake periods. This activity differed in its frequency, topography and source from the alpha rhythm that it accompanied. CONCLUSION: Based on these preliminary findings, we hypothesise that at times of sleep-wake transition in patients with exploding head syndrome, aberrant attentional processing may lead to amplification and modulation of external sensory stimuli.

Subjective Sleep Quality and Sleep Architecture in Patients With Migraine: A Meta-analysis.

BACKGROUND AND OBJECTIVES: Sleep disturbance is often associated with migraine. However, there is a paucity of research investigating objective and subjective measures of sleep in patients with migraine. This meta-analysis aims to determine whether there are differences in subjective sleep quality measured using the Pittsburgh Sleep Quality Index (PSQI) and objective sleep architecture measured using polysomnography (PSG) between adult and pediatric patients and healthy controls. METHODS: This review was preregistered on PROSPERO (CRD42020209325). A systematic search of 5 databases (Embase, MEDLINE, Global Health, APA PsycINFO, and APA PsycArticles, last searched on December 17, 2020) was conducted to find case-control studies that measured PSG or PSQI in patients with migraine. Pregnant participants and those with other headache disorders were excluded. Effect sizes (Hedges g) were entered into a random effects model meta-analysis. Study quality was evaluated with the Newcastle Ottawa Scale and publication bias with the Egger regression test. RESULTS: Thirty-two studies were eligible, of which 21 measured PSQI or Migraine Disability Assessment Test in adults, 6 measured PSG in adults, and 5 measured PSG in children. The overall mean study quality score was 5/9; this did not moderate any of the results and there was no risk of publication bias. Overall, adults with migraine had higher PSQI scores than healthy controls (g = 0.75, p < 0.001, 95% confidence interval [CI] 0.54-0.96). This effect was larger in those with a chronic rather than episodic condition (g = 1.03, p < 0.001, 95% CI 0.37-1.01; g = 0.63, p < 0.001, 95% CI 0.38-0.88, respectively). For polysomnographic studies, adults and children with migraine displayed a lower percentage of rapid eye movement sleep (g = -0.22, p = 0.017, 95% CI -0.41 to -0.04; g = -0.71, p = 0.025, 95% CI -1.34 to -0.10, respectively) than controls. Pediatric patients displayed less total sleep time (g = -1.37, p = 0.039, 95% CI -2.66 to -0.10), more wake (g = 0.52, p < 0.001, 95% CI 0.08-0.79), and shorter sleep onset latency (g = -0.37, p < 0.001, 95% CI -0.54 to -0.21) than controls. DISCUSSION: People with migraine have significantly poorer subjective sleep quality and altered sleep architecture compared to healthy individuals. Further longitudinal empirical studies are required to enhance our understanding of this relationship.

Cotard's Parasomnia: Le Délire de Negation that occur during the Sleep-Wake Dissociation?

NONE: Unpleasant dreamlike mentation can occur during NREM parasomnias, leading to associated panic attacks. The mentations are rarely remembered, and are likely underreported. However, they may lead to significant personal distress, and if not addressed, may contribute to poorer clinical outcomes. Cotard's 'Le Délire de Negation', are very rare nihilistic delusions, historically described with psychotic disorders. Their association with variety of neurologic disorders, including migraine and cluster-headache, has also been reported. Here we present three cases of Cotard's parasomnia during which distinct states of consciousness defined by nihilistic ideation are reported. Patients described believing to be dead or dying, whilst unable to perceive or experience their bodies in whole, or in part, as their own. The source analysis of electroencephalographic fingerprint of these mentations suggests right hemispheric hypoactivity subsequent to confusional arousals. Mechanistically, an aberrant activation of two major intrinsic brain networks of wakefulness, the salience and the default-mode-network is argued.

Cotard parasomnia: le délire de negation that occur during the sleep-wake dissociation?

None: Unpleasant dreamlike mentation can occur during non-rapid eye movement parasomnias, leading to associated panic attacks. The mentations are rarely remembered and are likely underreported. However, they may lead to significant personal distress and, if not addressed, may contribute to poorer clinical outcomes. Cotard le délire de negation are very rare nihilistic delusions, historically described with psychotic disorders. Their association with a variety of neurologic disorders, including migraine and cluster-headache, has also been reported. Here we present three cases of Cotard parasomnia during which distinct states of consciousness defined by nihilistic ideation occurred. Patients described believing they are dead or dying, while unable to perceive or experience their bodies in whole, or in part, as their own. A source analysis of the electroencephalographic fingerprint of these mentations suggests right-hemispheric hypoactivity subsequent to confusional arousals. Mechanistically, an aberrant activation of two major intrinsic brain networks of wakefulness, the salience network and the default mode network, is argued.