REM and NREM Sleep Parasomnia in Anti-NMDA Receptor Encephalitis.

OBJECTIVES: Encephalitis with anti-N-methyl-d-aspartate receptor antibodies (anti-NMDARe) is a rare disorder characterized by cognitive impairment, psychosis, seizures, and abnormal movements. Abnormal behaviors during REM sleep have not been described in anti-NMDARe. METHODS: Patients were monitored by video-polysomnography on a first night followed by multiple sleep latency tests and 18 hours of bed rest. RESULTS: Two patients with anti-NMDARe developed during the acute and postacute phase parasomnias including REM sleep behavior disorder and continuous finalistic quiet gesturing during a mixed N2/R sleep. The parasomnia disorder was improved by gabapentin and clonazepam. DISCUSSION: Video-polysomnography avoids misdiagnosing these parasomnia behaviors for seizure or movement disorders and allows adequate treatment.

Images: Sleep-related painful erection with concomitant hypnic headache.

Sleep-related painful erection (SRPE) is a parasomnia defined by the repetition of painful erections during rapid eye movement (REM) sleep. Hypnic headache (HH) is a primary headache occurring exclusively at night, often during REM sleep. We report the observation of a 33-year-old man with simultaneous SRPE and HH. Physical examination was normal. Comprehensive urological and endocrine explorations excluded other organic differential diagnoses. Polysomnography revealed several awakenings in REM, due to SRPE and concurrent HH. Medication by baclofen at bedtime seemed to have resulted in a decrease in SRPE episodes, confirmed by polysomnography, but at the cost of excessive daytime sleepiness, and was discontinued by the patient. Caffeine intake at bedtime was proposed, but the patient was reluctant because he was concerned about worsening insomnia. At 9-month follow-up, the patient had accepted his medical condition and was coping with both SRPE and HH. He felt reassured and wished no "overmedicalization." To our knowledge, the coexistence of both conditions has not yet been reported, yet their frequencies might be underestimated. We hypothesize a common underlying pathophysiology with a possible dysfunction of the vascular control and/or the autonomic nervous system and that could involve the hypothalamus. Somnologists should be aware of SRPE, potentially overlapping with HHs. SRPE should be considered in case of sleep-maintenance insomnia. Patient reassurance seems to be central in the care process of SRPE. CITATION: Moreau A, Monnier L, Medde A, Bourgin P, Ruppert E. Images: sleep-related painful erection with concomitant hypnic headache. J Clin Sleep Med. 2024;20(5):837-839.

Rapid Eye Movement Behavior Disorder and Other Parasomnias.

Rapid eye movement (REM) behavior disorder (RBD) is characterized by loss of skeletal muscle atonia that can lead to dream enactment. This condition can cause harm to patients and their bed partners if appropriate safety measures are not ensured. This condition is often the initial presenting symptom in a group of complex neurodegenerative processes. Definitive diagnosis requires a thorough history and an in-laboratory polysomnogram to look for evidence of REM sleep without atonia. Treatment options are limited but consist of sleep safety measures and pharmacotherapy. Patients diagnosed with idiopathic RBD associated with alpha-synucleinopathy are likely to have progression of disease.

The role of pedunculopontine nucleus in isolated REM sleep behavior disorder and REM sleep without atonia.

INTRODUCTION: The aim of this study was to analyze the functions of pedunculopontine nucleus (PPN) in isolated REM sleep behavior disorder (iRBD) and REM sleep without atonia (RSWA) to investigate the role of PPN in dream-enacting motor behaviors in RBD. We evaluated the activity of PPN through the prepulse modulation (PPM) together with other brainstem reflexes to investigate the differences in changes at brainstem. METHODS: We included nine patients with isolated RSWA and 10 patients with iRBD. For diagnosis, all patients underwent polysomnography. None of the patients had parkinsonism or dementia. We also included 17 healthy participants with similar age and sex. Blink reflex (BR), PPM of BR, recovery excitability of BR, and auditory startle reflex (ASR) were recorded in all participants. RESULTS: There was a prepulse inhibition deficit in iRBD and RSWA groups compared to healthy subjects. The BR-R2 recovery at 200 ms interval was also higher in patients with iRBD and RSWA. In ASR recordings, the response probabilities were higher in the RBD group compared to RSWA and control groups. CONCLUSION: The PPM was abnormal in both iRBD and RSWA whereas ASR was enhanced in iRBD. We suggest that there are certain similarities and differences in the pathophysiologies of iRBD and RSWA.

Trastornos del movimiento y de la conducta durante el sueño en el adulto / Sleep-related movement and behavioural disorders in adults

Los trastornos del movimiento y de la conducta durante el sueño pueden tener un impacto en la calidad del sueño del paciente y dar lugar a síntomas diurnos. En estos grupos de enfermedades se incluyen entidades como el síndrome de piernas inquietas, los movimientos periódicos de las piernas y las parasomnias del sueño de movimientos oculares rápidos (REM) y no REM. El conocimiento de sus características clínicas y nociones sobre su manejo es de gran importancia para el neurólogo y especialista en sueño por su frecuencia e impacto en la calidad del sujeto. Con frecuencia, estos pacientes son referidos a dichos especialistas, y es relevante conocer que ciertos trastornos del sueño pueden asociarse a otras enfermedades neurológicas

Sleep-related movement and behaviour disorders may have an impact on sleep quality and lead to daytime symptoms. These groups of conditions include diseases such as restless legs syndrome, periodic leg movements, and REM and NREM parasomnias. The knowledge of their clinical features and management is of utmost importance for the neurologist and sleep specialist. Frequently, these patients are referred to such specialists and it is relevant to know that certain sleep disorders may be associated with other neurological conditions

Rapid Eye Movement Sleep Behavior Disorder and Other Rapid Eye Movement Parasomnias.

PURPOSE OF REVIEW: The discovery of rapid eye movement (REM) sleep and, in particular, REM sleep behavior disorder (RBD) have brought elusive nightmarish experiences to scientific scrutiny. This article summarizes a century of sleep research to examine the maladies of dreaming, their pathophysiologic significance, and management. RECENT FINDINGS: Under healthy physiologic conditions, REM sleep is characterized by vivid mentation combined with skeletal muscle paralysis. The loss of REM sleep atonia in RBD results in vivid, potentially injurious dream enactment to patients and bed partners. RBD is common, affecting at least 1% of the population and is primarily caused by α-synuclein pathology of REM sleep-related brainstem neurons. The majority of patients with RBD ultimately develop a neurodegenerative syndrome such as Parkinson disease, dementia with Lewy bodies, or multiple system atrophy. Among patients with Parkinson disease, RBD predicts an aggressive disease course with rapid cognitive, motor, and autonomic decline. RBD is diagnosed by the presence of dream enactment episodes (either recorded or clinically recalled) and physiologic evidence of REM sleep without atonia demonstrated on polysomnography. Bedroom safety is of paramount importance in the management of RBD while pharmacokinetic options include melatonin or clonazepam. SUMMARY: The injurious dream enactment of RBD is common and treatable. It is a syndrome of α-synuclein pathology with most patients ultimately developing Parkinson disease, dementia with Lewy bodies, or a related disorder.

REM-sleep related hypermotor seizures: Video documentation and ictal source imaging.

INTRODUCTION: Rapid eye movement (REM) sleep has an inhibitory effect on epileptiform EEG discharges, and seizures occur extremely rarely in REM sleep. CASE STUDY: We present the case and video recordings of a 10-year-old boy, with sleep-related hypermotor seizures starting from REM sleep, identified from videoEEG recordings. The semiology comprised intense fear, tachycardia, tachypnea, followed by hypermotor manifestations. Further investigations included brain MRI and source localization of the EEG signals. Multiple antiepileptic drugs were tried, the patient obtaining a good control of the seizures in the last 2.5 years with eslicarbazepine. DISCUSSION AND CONCLUSION: The ictal EEG source imaging showed seizure onset in the anterior part of the right insula, with propagation to the orbitofrontal area, confirmed by the semiological sequence. Although rare, focal seizures can be triggered by REM sleep and our findings suggest that deficient maturation of brain areas involved in sleep modulation might induce insufficient desynchronization during REM sleep, thus allowing seizure emergence.

Rare disorders of penile erection.

This literature review presents two unusual and mystifying disorders of penile erection: painful nocturnal erections, alternatively termed sleep-related painful erections, and idiopathic stuttering priapism, a variant of recurrent ischemic priapism in which no cause is discernible. The disorders are closely related although they are distinct clinically and pathologically. The main subject areas of discussion are recognition, clinical evaluation and management although current concepts surrounding their causes and mechanisms are also addressed. It is acknowledged that despite the perceived rarities of these disorders they are impactful in terms of their disease profiles and consequences. Future advances in their management will require continued development of evidence-based treatments.

REM sleep without atonia and the relation with Lewy body disease.

REM sleep without atonia (RSWA) is the polysomnographic finding of persistent muscle tone during REM sleep, resulting in paroxysmal phasic or tonic EMG activity. RSWA is essential for the diagnosis of REM sleep behavior disorder (RBD), but can also occur without dream-enacting behavior. Loss of atonia during REM sleep is considered as a biomarker for synucleinopathies. We will give an overview of the pathophysiology of RSWA and will highlight the diagnostic methods for RSWA. We will describe the different etiologies of RSWA and finally we will focus on the role of RSWA as biomarker for Lewy body disease. RSWA severity in isolated RBD patients is a potential predictor for early conversion to Parkinson's disease (PD) or dementia with Lewy bodies. In PD patients, RSWA severity is associated with more severe motor symptoms and disease progression. Future studies are needed to delineate the importance of isolated RSWA as prodromal marker of Lewy body disease.

Clinical neurophysiology of REM parasomnias.

Rapid eye movement (REM) sleep behavior disorder (RBD), sleep paralysis, and nightmare disorder are the three REM sleep parasomnias outlined by the International Classification of Sleep Disorders. In this review we address the clinical neurophysiology of these disorders. The majority of neurophysiologic studies have been conducted in RBD, and fewer studies have evaluated patients with nightmare disorder or isolated sleep paralysis. Neurophysiologic studies of REM sleep parasomnias mostly used polysomnography (PSG), or were performed on animals to shed light on the pathophysiology of these disorders. Fewer studies used electoencephalography or electromyography outside the context of PSG, evoked potentials, or autonomic neurophysiologic studies. In this chapter, the main neurophysiologic findings in REM sleep parasomnias are described and their implications and relevance are discussed.

Clinical profiles of late-onset psychiatric patients exhibiting incidental REM sleep without atonia.

Rapid eye movement (REM) sleep without atonia (RWA), which is a hallmark of REM sleep behavior disorder (RBD) on polysomnography (PSG), may represent specific characteristics of prodromal Parkinson's disease (PD)/dementia with Lewy bodies (DLB), even when dream-enactment behavior is absent. We investigated the clinical profiles associated with PD/DLB in late-onset psychiatric patients exhibiting incidental RWA. Among patients who underwent PSG in our psychiatric ward, eight with incidental RWA, nine with idiopathic RBD, and seven with PD or DLB who had preceding RBD were included. Clinical variables, including the percentage of RWA in the total REM sleep (%RWA), were compared among the three groups. The frequency of depressive disorders as a primary psychiatric diagnosis and antidepressant usage were significantly higher in the incidental RWA group than in the other groups. There were no differences in the prevalence of supportive features of DLB among the three groups. The median %RWA was significantly lower in the incidental RWA group than in the other groups. Although the cardiac 123I-metaiodobenzylguanidine uptake was significantly higher in the incidental RWA group compared with the other groups, the groups showed overlap in the specific binding ratios on dopamine transporter imaging. All patients in the three groups exhibited cingulate island sign ratios on brain perfusion single-photon emission computed tomography within a threshold of 0.281, which is the optimal cut-off value for a diagnosis of DLB. In this series, late-onset psychiatric patients with incidental RWA partially shared common clinical profiles with idiopathic RBD and PD/DLB.

Differences in rapid eye movement (REM) sleep abnormalities between posttraumatic stress disorder (PTSD) and major depressive disorder patients: REM interruption correlated with nightmare complaints in PTSD.

OBJECTIVE: The presence of repeated nightmares in posttraumatic stress disorder (PTSD) has been hypothesized as a dysfunction of rapid eye movement (REM) sleep, but there has been remarkably little agreement about the pathophysiology. This presents a deterrent to more effective treatments. REM sleep abnormalities including elevated REM density also have been replicated in major depressive disorder (MDD). The purpose of this study was to clarify the difference of REM sleep abnormalities between the two disorders for understanding the pathophysiology of sleep disturbances in PTSD. METHODS: Polysomnographic measures were compared among 14 PTSD patients (aged 23.7 ± 5.5 years) and 14 MDD patients (aged 27.9 ± 10.1 years) under drug-naive or drug-free conditions. We defined REM interruption by summing the intrusive wake times during the REM period and adding the subsequent wake times to the last epoch of REM period. The significant polysomnographic measures were correlated with PTSD symptoms within the PTSD group. RESULTS: REM interruption was significantly increased in the PTSD group compared with the MDD group (12.2 vs 2.1 min, p = 0.001). REM density was also significantly increased in the PTSD group compared with the MDD group (30.5 vs 23.1%, p = 0.019). Within the PTSD group, we found significant correlations between the severity of trauma-related nightmare complaints and the percentage of REM interruption (R = 0.62, p = 0.017), but not REM density. CONCLUSIONS: REM sleep abnormalities are different between PTSD and MDD. Increased REM interruption may be a biological marker correlated with nightmare complaints in PTSD patients. Treatments including pharmacotherapy that reduces REM interruption might ameliorate nightmares in PTSD.

Sleep-Related Painful Erections: A Meta-Analysis on the Pathophysiology and Risks and Benefits of Medical Treatments.

BACKGROUND: Patients with sleep-related painful erections (SRPEs) have frequent awakenings from deep penile pain during nocturnal erections. This results in severe sleep deprivation. AIM: To review the current literature on SRPEs and discuss the pathophysiologic theories and risks and benefits of medical treatments. METHODS: PubMed was searched using the terms sleep-related painful erections, nocturnal priapism, treatment, and sleep-related erections. OUTCOME: Variables included patient demographics, medical history, diagnostics, hypotheses on pathophysiology, and treatment modalities and their effect on SRPE in the short and long term. RESULTS: The search yielded in 66 SRPE cases that were analyzed, including our mono-institutional series of 24 patients. The phenomenon of SRPEs is not well understood. Theories about pathophysiology concerned increased serum testosterone levels, altered autonomic function, compression of the lateral preoptic area, coexistent obstructive sleep apnea syndrome, the existence of a "compartment syndrome," and psychosomatic factors. Except for polysomnographic findings that showed sleep fragmentation and decreased sleep efficiency in all patients, other diagnostic results varied widely. Multiple agents were tried. Baclofen and, to lesser degree, clonazepam showed noticeable results, most likely due to their influence on the γ-aminobutyric acid system and, hence, suppression of glutamate release. In addition, baclofen relaxes the ischiocavernosus and bulbospongiosus muscles, which are involved in penile erection. CLINICAL IMPLICATIONS: By providing a critical analysis and complete overview on the limited literature about this overlooked and undermanaged condition, this review contributes to a better understanding of the pathophysiology and provides directions for future research on the treatment of SRPE. STRENGTHS AND LIMITATIONS: Because the literature on SRPEs includes only case reports and small case series, the level of evidence of treatment advice is limited. CONCLUSION: The pathophysiology of SRPEs is not yet clarified. Further diagnostic evaluation, including electromyography of the ischiocavernosus and bulbospongiosus muscles to elucidate the pathophysiology, is recommended. Prospective controlled investigations are warranted to assess the efficacy and safety of long-term use of baclofen and develop evidence-based treatment advice. Vreungdenhil S, Weidenaar AC, de Jong IJ, van Driel MF. Sleep-Related Painful Erections: A Meta-Analysis on the Pathophysiology and Risks and Benefits of Medical Treatments. J Sex Med 2018;15:5-19.

Rapid Eye Movement Sleep Behavior Disorder and Other Rapid Eye Movement Sleep Parasomnias.

PURPOSE OF REVIEW: The most common rapid eye movement (REM) parasomnia encountered by neurologists is REM sleep behavior disorder (RBD), and nightmares are so frequent that every neurologist should be able to differentiate them from the dream enactment of RBD. Isolated sleep paralysis is relatively common and is often mistaken for other neurologic disorders. This article summarizes the current state of the art in the diagnosis of RBD, discusses the role of specific questionnaires and polysomnography in the diagnosis of RBD, and reviews recent studies on idiopathic RBD as an early feature of a synucleinopathy, secondary RBD, and its management. Recent diagnostic criteria and implications of nightmares and isolated sleep paralysis are also reviewed. RECENT FINDINGS: Idiopathic RBD can now be considered as part of the prodromal stage of a synucleinopathy. Therefore, an accurate diagnosis is mandatory, and this implies detection of REM sleep without atonia. The polysomnography montage, including EMG of the submentalis and flexor digitorum superficialis muscles, provides a high sensitivity and specificity for the diagnosis. The exact diagnosis is important for patient counseling and for future neuroprotective trials. SUMMARY: REM parasomnias include RBD, sleep paralysis, and nightmares, which have distinct clinical characteristics and different implications regarding diagnostic procedures, management, and prognosis.

Terror and bliss? Commonalities and distinctions between sleep paralysis, lucid dreaming, and their associations with waking life experiences.

Sleep paralysis and lucid dreaming are both dissociated experiences related to rapid eye movement (REM) sleep. Anecdotal evidence suggests that episodes of sleep paralysis and lucid dreaming are related but different experiences. In this study we test this claim systematically for the first time in an online survey with 1928 participants (age range: 18-82 years; 53% female). Confirming anecdotal evidence, sleep paralysis and lucid dreaming frequency were related positively and this association was most apparent between lucid dreaming and sleep paralysis episodes featuring vestibular-motor hallucinations. Dissociative experiences were the only common (positive) predictor of both sleep paralysis and lucid dreaming. Both experiences showed different associations with other key variables of interest: sleep paralysis was predicted by sleep quality, anxiety and life stress, whereas lucid dreaming was predicted by a positive constructive daydreaming style and vividness of sensory imagery. Overall, results suggest that dissociative experiences during wakefulness are reflected in dissociative experiences during REM sleep; while sleep paralysis is related primarily to issues of sleep quality and wellbeing, lucid dreaming may reflect a continuation of greater imaginative capacity and positive imagery in waking states.

Sleep-Related Painful Erections in a Patient With Obstructive Sleep Apnea Syndrome.

Sleep-related painful erection (SRPE) is a rare sleep disorder characterized by recurrent, painful penile erections occurring when awakening from rapid eye movement sleep, while erections are painless during wakefulness. Almost 35 cases have been reported worldwide, and only two of them had an associated obstructive sleep apnea syndrome (OSAS). We report a new case of a 61-year-old man suffering from SRPE associated with OSAS. The adequate treatment of respiratory events with continuous positive airway pressure did not alleviate the SRPE symptoms and excessive daytime sleepiness. The SRPE diagnosis was made by polysomnography coupled with video surveillance when the patient was referred to the sleep laboratory for residual excessive daytime sleepiness. The patient had 2-4 episodes of SRPE/night. Beta-blocker did not alleviate the SRPE, but a transient improvement was noted when the patient was treated with paroxetine. In contrast with the two previously published cases of SRPE plus OSAS, continuous positive airway treatment did not improve SRPE symptoms in our patient.

Distinctive features of NREM parasomnia behaviors in parkinson's disease and multiple system atrophy.

OBJECTIVE: To characterize parasomnia behaviors on arousal from NREM sleep in Parkinson's Disease (PD) and Multiple System Atrophy (MSA). METHODS: From 30 patients with PD, Dementia with Lewy Bodies/Dementia associated with PD, or MSA undergoing nocturnal video-polysomnography for presumed dream enactment behavior, we were able to select 2 PD and 2 MSA patients featuring NREM Parasomnia Behviors (NPBs). We identified episodes during which the subjects seemed to enact dreams or presumed dream-like mentation (NPB arousals) versus episodes with physiological movements (no-NPB arousals). A time-frequency analysis (Morlet Wavelet Transform) of the scalp EEG signals around each NPB and no- NPB arousal onset was performed, and the amplitudes of the spectral frequencies were compared between NPB and no-NPB arousals. RESULTS: 19 NPBs were identified, 12 of which consisting of 'elementary' NPBs while 7 resembling confusional arousals. With quantitative EEG analysis, we found an amplitude reduction in the 5-6 Hz band 40 seconds before NPBs arousal as compared to no-NPB arousals at F4 and C4 derivations (p<0.01). CONCLUSIONS: Many PD and MSA patients feature various NREM sleep-related behaviors, with clinical and electrophysiological differences and similarities with arousal parasomnias in the general population. SIGNIFICANCE: This study help bring to attention an overlooked phenomenon in neurodegenerative diseases.

Myotonic dystrophy type 1, daytime sleepiness and REM sleep dysregulation.

Myotonic dystrophy type 1 (DM1), or Steinert's disease, is the most common adult-onset form of muscular dystrophy. DM1 also constitutes the neuromuscular condition with the most significant sleep disorders including excessive daytime sleepiness (EDS), central and obstructive sleep apneas, restless legs syndrome (RLS), periodic leg movements in wake (PLMW) and periodic leg movements in sleep (PLMS) as well as nocturnal and diurnal rapid eye movement (REM) sleep dysregulation. EDS is the most frequent non-muscular complaint in DM1, being present in about 70-80% of patients. Different phenotypes of sleep-related problems may mimic several sleep disorders, including idiopathic hypersomnia, narcolepsy without cataplexy, sleep apnea syndrome, and periodic leg movement disorder. Subjective and objective daytime sleepiness may be associated with the degree of muscular impairment. However, available evidence suggests that DM1-related EDS is primarily caused by a central dysfunction of sleep regulation rather than by sleep fragmentation, sleep-related respiratory events or periodic leg movements. EDS also tends to persist despite successful treatment of sleep-disordered breathing in DM1 patients. As EDS clearly impacts on physical and social functioning of DM1 patients, studies are needed to identify the best appropriate tools to identify hypersomnia, and clarify the indications for polysomnography (PSG) and multiple sleep latency test (MSLT) in DM1. In addition, further structured trials of assisted nocturnal ventilation and randomized trials of central nervous system (CNS) stimulant drugs in large samples of DM1 patients are required to optimally treat patients affected by this progressive, incurable condition.