Polysomnographic Assessment of Sleep Comorbidities in Drug-Naïve Narcolepsy-Spectrum Disorders--A Japanese Cross-Sectional Study

Diagnostic challenges and burden of idiopathic hypersomnia: a systematic literature review

Idiopathic hypersomnia (IH) is a rare neurological sleep disorder, characterized by excessive daytime sleepiness despite normal sleep duration, that can significantly impact patient's lives. The burden of IH goes beyond excessive daytime sleepiness, pervading all aspects of everyday life. Characteristic and burdensome symptoms of IH include sleep inertia/drunkenness, long sleep duration, and daytime cognitive dysfunction. This systematic review assessed current knowledge regarding IH diagnostic challenges and burden of illness. Literature searches for original epidemiological, clinical, humanistic, or economic research relevant to IH published between 2012 and 2022 in MEDLINE, Embase, Cochrane, gray literature (diagnostic criteria and treatment guidelines), conferences (2019-2022), and clinical trial databases yielded 97 articles. Findings indicate that IH remains a poorly defined diagnosis of exclusion that is difficult to distinguish from narcolepsy type 2 because of symptom overlap and inadequacies of objective testing. Consequently, individuals with IH endure diagnostic delays of up to 9 years. The economic burden of IH has not been characterized to any appreciable extent. Pharmacological treatment options can improve symptoms and functional status, but rarely restores normal levels of functioning. These findings highlight the need to reclassify central disorders of hypersomnolence. Further collaboration is now required between research groups to identify and validate objective markers to help redefine diagnostic criteria for IH. This would move IH into a position that could benefit from future targeted therapeutic interventions. The study was funded by Takeda Development Center Americas, Inc.

[Abnormal nocturnal behavior mimicking REM sleep behavior disorder episodes in a patient with periodic limb movement disorder]

Periodic limb movement disorder (PLMD) is a condition in which patients experience frequent periodic limb movements of sleep (PLMS). Synchronized arousal responses cause sleep fragmentation, resulting in insomnia, daytime sleepiness, and fatigue. A 59-year-old man was identified as having intense sleep-talking and body movements, suggesting rapid eye movement (REM) sleep behavior disorder (RBD). Attended video-polysomnography (PSG) revealed that sleep-talking and body movements occurred only during non-REM sleep and were associated with PLMS-induced arousals (periodic leg movement arousal index, 53.2/h). Pramipexole administration improved events during sleep and daytime sleepiness, and the PSG findings and clinical course led to a diagnosis of PLMD. This case demonstrates that PLMD mimics the symptoms of RBD and that a detailed analysis of monitored video PSG is crucial to confirm the diagnosis of RBD and to identify or exclude other causes of sleep talking and behavior.

Narcolepsy and Idiopathic Hypersomnia

Narcolepsy types 1 and 2 and idiopathic hypersomnia are primary Central Nervous System (CNS) disorders of hypersomnolence characterized by profound daytime sleepiness and/or excessive sleep need. Onset of symptoms begins typically in childhood or adolescence, and children can have unique presentations compared with adults. Narcolepsy type 1 is likely caused by immune-mediated loss of orexin (hypocretin) neurons in the hypothalamus; however, the causes of narcolepsy type 2 and idiopathic hypersomnia are unknown. Existing treatments improve daytime sleepiness and cataplexy but there is no cure for these disorders.

Association of Periodic Limb Movements with Medication Classes: A Retrospective Cohort Study

OBJECTIVE

To investigate the association between various medication classes and the periodic limb movement index (PLMI) in a clinical cohort of adults who completed in-laboratory polysomnography.

METHODS

A single, diagnostic, overnight, in-laboratory polysomnogram was completed for 3,488 patients consecutively referred from 2010-2015 to determine the PLMI. Medication use and medical comorbidities were collected through patient questionnaires. Associations between medication classes and the PLMI were ascertained using multivariable ordinal logistic regression models.

RESULTS

The median age of the cohort was 56.0 years (48.2% male). After adjusting for age, sex, body mass index, relevant comorbidities, and sleep parameters, the use of selective serotonin reuptake inhibitors (SSRIs) (OR = 1.52) and serotonin-norepinephrine reuptake inhibitors (SNRIs) (OR = 1.99) were associated with an increased PLMI. Conversely, gabapentinoids (OR = 0.71), stimulants (OR = 0.52), benzodiazepines (OR = 0.79), and dopamine agonists (OR = 0.38) were associated with a decreased PLMI. A non-statistically significant trend for a decreased PLMI with neuroleptic use was observed. No significant associations were found between the PLMI and the use of antihypertensives, statins, tricyclic antidepressants, bupropion, anticoagulants, antiplatelets, modafinil, and antihistamines.

CONCLUSION

The use of SSRIs and SNRIs was associated with an elevated PLMI while the use of gabapentinoids, stimulants, benzodiazepines, and dopamine agonists was associated with a decreased PLMI. These results can assist physicians in managing PLMs and invite further research into the relationship between PLMs and medications with the modulating effects of dose, formulation type, and time of administration.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that SSRIs and SNRIs are associated with an elevated PLMI while gabapentinoids, stimulants, benzodiazepines, and dopamine agonists are associated with a decreased PLMI.

Dream enactment behavior: review for the clinician

NONE

Dream enactment behavior commonly occurs on occasion in normal children and adults. Disruptive and frequent dream enactment behavior may come to the attention of the clinician either as the primary reason for consultation or as a prominent characteristic of a patient with other sleep disorders. Questioning patients with chronic neurologic and psychiatric disorders may also reveal previously unrecognized behavior. In the absence of sleep pathology, process of dream enactment likely begins with active, often emotionally charged dream content that may occasionally break through the normal REM sleep motor suppressive activity. Disrupted sleep resulting from many possible causes, such as circadian disruption, sleep apnea, or medications, may also disrupt at least temporarily the motor-suppressive activity in REM sleep, allowing dream enactment to occur. Finally, pathological neurological damage in the context of degenerative, autoimmune, and infectious neurological disorders may lead to chronic recurrent and severe dream enactment behavior. Evaluating the context, frequency, and severity of dream enactment behavior is guided first and foremost by a structured approach to the sleep history. Physical exam and selected testing support the clinical diagnosis. Understanding the context and the likely cause is essential to effective therapy.

REM sleep behavior disorder in narcolepsy: A secondary form or an intrinsic feature?

Disrupted nighttime sleep is one of the pentad of symptoms defining Narcolepsy. REM sleep behavior disorder (RBD) largely contributes to night sleep disruption and narcolepsy is the most common cause of secondary RBD. However, RBD linked to narcolepsy (N-RBD) has been insufficiently characterized, leaving unsolved a number of issues. Indeed, it is still debated whether N-RBD is an intrinsic feature of narcolepsy, as indubitable for cataplexy, and therefore strictly linked to the cerebrospinal fluid hypocretin-1 (CSF hcrt-1) deficiency, or an associated feature, with a still unclear pathophysiology. The current review aims at rendering a comprehensive state-of-the-art of N-RBD, highlighting the open and unsettled topics. RBD reportedly affects 30-60% of patients with Narcolepsy type 1 (NT1), but it may be seen also in Narcolepsy type 2 (NT2). When compared to idiopathic/isolated RBD (iRBD), N-RBD has been reported to be characterized by less energetic and quieter episode, which however occur with the same probability in the first and the second part of the night and sometime even subcontinuously. N-RBD patients are generally younger than those with iRBD. N-RBD has been putatively linked to wake-sleep instability due to CSF hcrt-1 deficiency, but this latter by itself cannot explain completely the phenomenon as N-RBD has not been universally linked to low CSF hcrt-1 levels and it may be observed also in NT2. Therefore, other factors may probably play a role and further studies are needed to clarify this issue. In addition, therapeutic options have been poorly investigated.

Pediatric Sleep Disorders

PURPOSE OF REVIEW

This article provides an overview of the clinical features, diagnosis, and treatment of insomnia, restless legs syndrome, periodic limb movements of sleep, parasomnias, narcolepsy, and sleep-related breathing disorders among children and adolescents.

RECENT FINDINGS

Pediatric presentations of sleep disorders differ from adult presentations, making diagnosis challenging. Specific clinical syndromes, such as cataplexy in children with narcolepsy type 1, can have an altogether different presentation compared to adult-onset symptoms, contributing to diagnostic delays and potential misdiagnoses. More broadly, research shows strong associations between sleep and daytime cognition, mood, and behavior among children with and without neurologic conditions and thus suggests a need to identify and treat sleep problems to optimize daytime functioning.

SUMMARY

Addressing sleep problems in children with neurologic conditions and neurodevelopmental disorders improves quality of life for patients and their families and, in many cases, reduces neurologic disease burden.

Idiopathic Hypersomnia

Idiopathic hypersomnia (IH) is a chronic neurologic disorder of daytime sleepiness, accompanied by long sleep times, unrefreshing sleep, difficulty in awakening, cognitive dysfunction, and autonomic symptoms. The cause is unknown; a genetic predisposition is suggested. Autonomic, inflammatory, or immune dysfunction has been proposed. Diagnosis involves a clinical history and objective testing. There are no approved treatments for IH, but modafinil is typically considered first-line. A substantial fraction of patients with IH are refractory or intolerant to standard treatments, and different treatment strategies using novel therapeutics are necessary. Even with current treatment options, quality of life and safety may remain impaired.

Insomnia, parasomnias, and narcolepsy in children: clinical features, diagnosis, and management

Sleep problems are frequently encountered as presenting complaints in child neurology clinical practice. They can affect the functioning and quality of life of children, particularly those with primary neurological and neurodevelopmental disorders, since coexisting sleep problems can add substantially to neurocognitive and behavioural comorbidities. Additionally, symptoms of some sleep disorders such as parasomnias and narcolepsy can be confused with those of other neurological disorders (eg, epilepsy), posing diagnostic challenges for paediatric neurologists. The understanding of the neurophysiology of sleep disorders such as insomnia, parasomnias, and narcolepsy is still evolving. There is a complex relation between the sleeping brain and its waking function. The interplay among genetic factors, alterations in neurotransmitters, electrophysiological changes, and environmental factors potentially contribute to the genesis of these sleep disorders.

Periodic limb movements in sleep are followed by increases in EEG activity, blood pressure, and heart rate during sleep

Purpose

Periodic limb movements in sleep (PLMS) are related to arousal, sympathetic activation, and increases in blood pressure (BP), but whether they are part of the arousal process or causative of it is unclear. Our objective was to assess the temporal distribution of arousal-related measures around PLMS.

Methods

Polysomnographic recordings of six patients with restless legs syndrome were analyzed. We analyzed 15 PLMS, plus three 5-s epochs before and after each movement, for every patient. Mean values per epoch of blood pressure (BP), heart rate (HR), and electroencephalographic (EEG) power were calculated. For each patient, six 5-s epochs of undisturbed sleep were analyzed as controls.

Results

Alpha + beta EEG power, systolic BP, and HR were significantly increased following PLMS. The EEG power and HR increases were noticed in the first epoch after PLMS, whereas that of systolic BP was observed in the second and third epochs following a PLMS. No significant changes occurred in the epochs of undisturbed sleep.

Conclusions

The results suggest that PLMS are followed by arousal-related nervous system events. Given the high frequency of PLMS throughout the night, they could be a potential risk factor for nocturnal arrhythmias and hypertension, in addition to causing sleep deprivation.