The distinct roles of OSA and depression severity in day- and night-time symptomatology in OSA patients: a pilot study.

PURPOSE: Obstructive sleep apnoea (OSA) is a common sleep disorder and is associated with a number of comorbid conditions, including the frequent occurrence of depression. Notably, there is a considerate overlap in day- as well as night-time symptomatology in depression and OSA. In light of this, we aimed to disentangle the distinct effects of OSA and depression severity on day- and night-time symptomatology. METHODS: This pilot study (N = 320) utilized a retrospective chart review design and included both males and females who met the minimum diagnostic criteria for OSA. Daytime symptoms (sleepiness and fatigue) were assessed via questionnaires, while night-time symptoms were measured via polysomnography. RESULTS: Main findings include the following: (a) no association between OSA and depression severity, (b) depression severity significantly predicted increased sleepiness and fatigue (c) OSA severity significantly predicted increased stage 2 non-rapid eye movement sleep percentage, (d) OSA significantly predicted decreased stage 3 non-rapid eye movement sleep percentage and rapid eye movement sleep percentage. Overall, depression severity exerts the strongest influence on daytime symptomatology, while OSA severity exerts the strongest influence on night-time symptomatology. Moreover, with the exception of sleepiness, no overlap between day- and night-time findings was detected. CONCLUSION: OSA and depression, although comorbid, possibly constitute distinct disease processes in this population group. Consequently, solely devising treatment targeting a reduction in apnoea-hypopnoea index might not be sufficient in alleviating debilitating daytime symptoms in treatment-seeking individuals.

The nonrapid eye movement parasomnias: recent advances and forensic aspects.

PURPOSE OF REVIEW: The aim is to update the readership on recent advances in the diagnosis and classification of nonrapid eye movement (NREM) sleep parasomnias with an emphasis on recent research findings and related forensic consequences of the parasomnias. RECENT FINDINGS: The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) has further refined the classification and diagnostic criteria for the parasomnias, dividing them into non-REM and REM sleep disorders. It has removed confusional arousal disorder and updated the diagnostic criteria in keeping with the evidence-base available at the time of its final drafting. New research subsequent to the final drafting of the DSM-5 has clarified certain aspects including those related to the risk factors ('triggers') for sleepwalking and the impact of sleepwalking on daytime functioning, social and occupational functioning. These new research data should be considered in the development of the next International Classification of Sleep Disorders. The new diagnostic system and research data provide further clarity for the forensic sleep medicine practitioner. SUMMARY: The DSM-5 diagnostic criteria combined with the latest research will inform both clinical and forensic sleep medicine practice and provide further impetus for evidence-based practice.

Alcohol and sleep I: effects on normal sleep.

This review provides a qualitative assessment of all known scientific studies on the impact of alcohol ingestion on nocturnal sleep in healthy volunteers. At all dosages, alcohol causes a reduction in sleep onset latency, a more consolidated first half sleep and an increase in sleep disruption in the second half of sleep. The effects on rapid eye movement (REM) sleep in the first half of sleep appear to be dose related with low and moderate doses showing no clear trend on REM sleep in the first half of the night whereas at high doses, REM sleep reduction in the first part of sleep is significant. Total night REM sleep percentage is decreased in the majority of studies at moderate and high doses with no clear trend apparent at low doses. The onset of the first REM sleep period is significantly delayed at all doses and appears to be the most recognizable effect of alcohol on REM sleep followed by the reduction in total night REM sleep. The majority of studies, across dose, age and gender, confirm an increase in slow wave sleep (SWS) in the first half of the night relative to baseline values. The impact of alcohol on SWS in the first half of night appears to be more robust than the effect on REM sleep and does not appear to be an epiphenomenon REM sleep reduction. Total night SWS is increased at high alcohol doses across gender and age groups.

Sleep stage sequence analysis of sleep onset REM periods in the hypersomnias.

BACKGROUND: The Multiple Sleep Latency Test (MSLT) remains an important diagnostic tool in the diagnosis of hypersomnias. However, a positive MSLT may be found in other sleep disorders, such as behaviourally induced inadequate sleep syndrome (BIISS). It has been demonstrated that in sleep onset rapid eye movement (SOREM) periods in BIISS, REM sleep tends to arise from stage 2 sleep (non-REM (NREM) 2), rather than stage 1 sleep (NREM1), as in narcolepsy. METHODS: We performed sleep stage sequence analysis on 127 patients with nocturnal polysomnography and MSLT, including 25 with narcolepsy with cataplexy (N+C), 41 with narcolepsy without cataplexy (N-C), 21 with idiopathic hypersomnia with long sleep time (IHL), 20 with BIISS and 20 with periodic limb movement disorder (PLMD). 537 naps were recorded, containing 176 SOREM periods. RESULTS: All SOREM periods in the IHL, BIISS and PLMD groups arose from NREM2 sleep, 75% of those in N+C arose from NREM1 and in N-C only 52% arose from NREM1. Within the N-C group, those with SOREM periods all arising from stage 1 had a shorter MSL (p=0.02). CONCLUSIONS: These results suggest that SOREM periods arising from NREM1 have high sensitivity for the diagnosis of narcolepsy and that SOREM periods from NREM1 are a marker of severity, either of sleepiness or REM instability. Sleep stage sequence analysis of SOREM periods may also aid more accurate phenotyping of the hypersomnias and in particular clarify heterogeneity among patients with narcolepsy without cataplexy.

Sleep-related automatism and the law.

Crimes carried out during or arising from sleep highlight many difficulties with our current law and forensic sleep medicine clinical practice. There is a need for clarity in the law and agreement between experts on a standardised form of assessment and diagnosis in these challenging cases. We suggest that the time has come for a standardised, internationally recognised diagnostic protocol to be set as a minimum standard in all cases of suspected sleep-related forensic cases. The protocol of a full medical history, sleep history, psychiatric history, neuropsychiatric and psychometric examination and electroencephalography (EEG), should be routine. It should now be mandatory to carry out routine polysomnography (PSG) to establish the presence of precipitating and modulating factors. Sleepwalking is classified as insane automatism in England and Wales and sudden arousal from sleep in a non-sleepwalker as sane automatism. The recent case in England of R v. Lowe (2005) highlights these anomalies. Moreover, the word insanity stigmatises sleepwalkers and should be dropped. The simplest solution to these problems would be for the law to be changed so that there is only one category of defence for all sleep-related offences--not guilty by reason of sleep disorder. This was rejected by the House of Lords for cases of automatism due to epilepsy, and is likely to be rejected for sleepwalkers. Removing the categories of automatism (sane or insane) would be the best solution. Risk assessment is already standard practice in the UK and follow up, subsequent to disposal, by approved specialists should become part of the sentencing process. This will provide support for the defendant and protection of the public.

Somnambulistic sexual behaviour (sexsomnia).

Somnambulism or sleepwalking is a viable defence on the basis of automatism. The behaviours that occur during sleepwalking can be highly complex and include sexual behaviour of all types. Somnambulistic sexual behaviour (also called sexsomnia, sleep sex) is considered a variant of sleepwalking disorder as the overwhelming majority of people with Sexsomnia have a history of parasomnia and a family history of sleepwalking. Sexual behaviour during a sleep automatism can vary from explicit sexual vocalisations, to violent masturbation, to complex sexual acts including anal, oral and vaginal penetration. A recent case in England is reported where the defendant was acquitted on 3 charges of rape on the basis of automatism due to somnambulistic sexual behaviour.

REM sleep behavior disorder--psychiatric presentations: a case series from the United Kingdom.

Rapid eye movement sleep behavior disorder (RBD) has rarely been associated with a psychiatric condition. We report a series of cases of RBD presenting as psychiatric disorders. These patients were assessed at a specialist sleep disorders center and investigated using polysomnography and, where appropriate, magnetic resonance imaging of the brain and neuropsychological tests. These cases of RBD highlight the varying presentations and causes of RBD that may involve psychiatrists, sleep specialists, and primary care physicians. These include idiopathic RBD presenting as depression, antidepressant-induced RBD, and a patient with undiagnosed Parkinson disease presenting with RBD. There is an increasing body of knowledge about RBD. At least 10% of patients with RBD are likely to present with psychiatric symptoms. It is essential that the condition is recognised and distinguished from other causes of sleep interruption. After recognizing the disorder, it is essential that the clinician undertake a thorough assessment, including a sleep history and formal investigation of sleep patterns at a specialized unit.

Posttraumatic narcolepsy--two case reports and a mini review.

STUDY OBJECTIVES: Hypersomnia following head injury is quite common, but the diagnosis of posttraumatic narcolepsy has tended to court controversy to the extent that the existence of this disorder has been questioned. The recent discovery of the hypocretins (orexins) and the subsequent confirmation that their deficiency causes narcolepsy have shed light on the pathophysiology of narcolepsy. Damage to or dysfunction of the hypothalamic cells that produce hypocretin (orexin), from whatever cause, can give rise to narcolepsy. We have conducted a review of the literature on the subject and have included only those cases that have been confirmed by polysomnography. There are approximately 20 polysomnography-confirmed cases of posttraumatic narcolepsy published in the literature, to which we add a further 2 cases. The results suggest that patients with posttraumatic narcolepsy are a heterogeneous group with respect to clinical presentation, nature and severity of injury, time from index event to symptom onset, and HLA type. There is some evidence that this type of narcolepsy may follow a progressive course, suggesting that the index event sets off a cascade sequence that may involve the hypocretin system. Further research in this area is required to answer these hypotheses.