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.

NREM parasomnias: a treatment approach based upon a retrospective case series of 512 patients.

BACKGROUND: Non-REM parasomnias are not uncommon conditions in the general population. Current treatment options are based on small case series and reports. In this study, we aimed to present the clinical experience from a large cohort of patients. PATIENTS: Five hundred and twelve patients with Non-REM parasomnia or parasomnia overlap disorder (POD), who had undergone a video polysomnography and were exposed to treatment, were retrospectively identified. Treatment outcome was assessed based on patients' reports, and treatment approach on a locally accepted hierarchy of interventions. RESULTS: Forty percent of patients were diagnosed with sleepwalking, 23.8% with mixed-phenotype and 10% with POD. Ultimately, 97.2% reported adequate control of their symptoms. Moreover, 60.1% were treated with pharmacotherapy and 32.0% without, consistent across all phenotypes (p = 0.09). Benzodiazepines were the most common drugs prescribed (47.1%, p < 0.05). In the end, 37.7% of our patients were receiving a benzodiazepine as part of their successful treatment, 11.7% an antidepressant, 9.2% a z-drug, and 10.7% melatonin. Finally, 13.2%, 12.1%, and 5.8% of our patients reported good control of their symptoms with sleep hygiene, management of sleep-disordered breathing, and psychological interventions (cognitive behavioral therapy [CBT] or mindfulness-based stress reduction [MBSR]), as monotherapy, respectively. CONCLUSION: The treatment approach to effective treatment of the patients with Non-REM parasomnias or POD offering first sleep hygiene advice, next treatment of concurrent sleep disorders and management of other priming factors like stress and anxiety, and lastly pharmacotherapy for Non-REM parasomnia is supported by our results. Non pharmacological interventions were effective in one third of our patients, and CBT/MBSR and melatonin appeared promising new treatments.

Safety and efficacy of long-term use of sodium oxybate for narcolepsy with cataplexy in routine clinical practice.

BACKGROUND: Sodium oxybate is licensed in Europe for the treatment of narcolepsy with cataplexy in adults. The aim of this study was to assess the efficacy and safety of sodium oxybate in clinical practice in patients with narcolepsy and cataplexy refractory to other treatments. MATERIALS AND METHODS: This was a retrospective single centre study including patients with severe narcolepsy with cataplexy refractory to other treatments, who were initiated on sodium oxybate between 2009 and 2015. Patients were allowed to be on other stimulants or/and anti-cataplectic agents. Epworth sleepiness scale (ESS) and weekly cataplexy events were recorded. Side effects (SEs) were recorded at every follow-up visit. RESULTS: 90 patients were prescribed sodium oxybate, with a total of 3116 patient-months of drug exposure. ESS and weekly cataplexy events were significantly reduced by sodium oxybate for all patients (ΔESS = 4.3 ± 4.4 and Δcataplexy = 21.8 ± 18.5 events/week; p < 0.0001, respectively). The required maintenance dose could not be predicted based upon gender, body mass index, or clinical factors. 60% of patients were able to reduce or come off other medications. Half of the patients experienced at least one SE, and 26.6% had to stop treatment due to limiting SEs. Nausea, mood swings and enuresis were the most commonly reported SEs. SEs that led to drug discontinuation, particularly psychosis, were associated with increasing age and were observed early after the initiation of the drug. CONCLUSIONS: Sodium oxybate provides a good clinical efficacy and acceptable safety profile in routine clinical practice for the treatment of patients suffering from narcolepsy with cataplexy. A quarter of patients experience SEs requiring withdrawal of the drug with older patients being more vulnerable to the more serious SEs.

Catathrenia, a REM predominant disorder of arousal?

OBJECTIVES: Catathrenia is an uncommon and poorly understood disorder, characterized by groaning during sleep occurring in tandem with prolonged expiration. Its classification, pathogenesis, and clinical relevance remain debated, substantially due to the limited number of cases reported to date. We report a series of consecutive cases of catathrenia, their clinical and polysomnographic characteristics, and their subsequent management. METHODS: Consecutive patients with catathrenia who had undergone full polysomnography in our institution over a 5.5-year period were included. Catathrenia events (CEs) were examined in clusters, which formulated catathrenia periods (CPs). The relationships between CPs, sleep stage distribution, electroencephalogram (EEG) arousals, and other sleep parameters were assessed, along with the clinical presentation and management of catathrenic patients. RESULTS: A total of 427 CPs were identified in 38 patients, 81% arising from rapid eye movement (REM) sleep. EEG arousals preceded or coincided with the onset of 84% of CPs, which were of longer duration than those not associated with an arousal (57.3 ± 56.8 vs. 32.2 ± 29.4 s, p < 0.001). Each CE had a characteristic airflow signal, with inspiration preceding a protracted expiration and a brief more rapid exhalation, followed by deep inspiration. Although the majority of patients were referred on the basis of bed partner complaints, 44.7% complained of daytime sleepiness. Continuous positive airway pressure therapy and sleep-consolidating pharmacotherapy led to subjective improvement, but were limited by poor long-term adherence. CONCLUSIONS: In the largest series of catathrenia patients reported to date, we found that this rare disorder is characterized by a distinct breathing pattern and arises predominantly from REM sleep, with arousals almost uniformly preceding or coinciding with the onset of CPs.

Emerging co-morbidities of obstructive sleep apnea: cognition, kidney disease, and cancer.

Obstructive sleep apnea (OSA) causes daytime fatigue and sleepiness, and has an established relationship with cardiovascular and metabolic disease. Recent years have seen the emergence of an evidence base linking OSA with an increased risk of degenerative neurological disease and associated cognitive impairment, an accelerated rate of decline in kidney function with an increased risk of clinically significant chronic kidney disease (CKD), and with a significantly higher rate of cancer incidence and death. This review evaluates the evidence base linking OSA with these seemingly unrelated co-morbidities, and explores potential mechanistic links underpinning their development in patients with OSA, including intermittent hypoxia (IH), sleep fragmentation, sympathetic excitation, and immune dysregulation.

The Montreal Cognitive Assessment: validity and utility in a memory clinic setting.

OBJECTIVE: To prospectively validate the Montreal Cognitive Assessment (MoCA) in a UK memory clinic. METHOD: We administered the MoCA and Mini-Mental State Examination (MMSE) to 32 subjects fulfilling diagnostic criteria for dementia, to 23 subjects fulfilling diagnostic criteria for mild cognitive impairment (MCI), and to 12 memory clinic comparison subjects, at baseline and then at 6-month follow-up. Clinical diagnoses for dementia and MCI were made according to ICD-10 and Petersen criteria. The sensitivity and specificity of both measures were assessed for detection of MCI and dementia. RESULTS: With a cut-off score of 26, the MMSE had a sensitivity of 17% to detect subjects with MCI, whereas the MoCA detected 83%. The MMSE had a sensitivity of 25% to detect subjects with dementia, whereas the MoCA detected 94%. Specificity for the MMSE was 100%, and specificity for the MoCA was 50%. Of subjects with MCI, 35% developed dementia within 6 months, and all scored less than 26 points on the MoCA at baseline. CONCLUSIONS: The MoCA is a useful brief screening tool for the detection of mild dementia or MCI in subjects scoring over 25 points on the MMSE. In patients already diagnosed with MCI, the MoCA helps identify those at risk of developing dementia at 6-month follow-up.