Latency To N3 Interruption In Arousal Disorders.

STUDY OBJECTIVES: To help expert witnesses in criminal cases using the "sleepwalking defense", we studied the time of first and last interruptions from stage N3 in patients with arousal disorders, including sexsomnia, as well as their determinants. METHODS: The epochs of lights off, sleep onset, first N3 interruption (with and without behaviors), and last N3 interruption were determined by videopolysomnography on two consecutive nights in 163 adults with disorders of arousal, including 46 with and 117 without sexsomnia. RESULTS: The first N3 interruption (independently of concomitant behavior) occurred as early as 8 minutes after sleep onset and within 100 minutes of falling asleep in 95% of cases. The first motor arousal from N3 occurred as early as 25 min after lights off time, a timing more variable between participants (between 30 and 60 minutes after lights off time in 25% of participants and within 60 minutes of falling asleep in 50%). These latencies did not differ between the groups with and without sexsomnia. No correlation was found between these latencies and the young age, sex or clinical severity. The latency of motor arousals was shorter when they were associated with a fast-wave EEG profile and were not preceded by another type of N3 arousal. CONCLUSION: The first motor arousal may occur early in the night in patients with arousal disorders, with or without sexsomnia, suggesting that abnormal behaviors occurring as early as 25 min after lights off time in clinical and criminal cases can be a parasomnia manifestation.

Idiopathic hypersomnia and Kleine-Levin syndrome.

Idiopathic hypersomnia (IH) and Kleine-Levin syndrome (KLS) are rare disorders of central hypersomnolence of unknown cause, affecting young people. However, increased sleep time and excessive daytime sleepiness (EDS) occur daily for years in IH, whereas they occur as relapsing/remitting episodes associated with cognitive and behavioural disturbances in KLS. Idiopathic hypersomnia is characterized by EDS, prolonged, unrefreshing sleep at night and during naps, and frequent morning sleep inertia, but rare sleep attacks, no cataplexy and sleep onset in REM periods as in narcolepsy. The diagnosis requires: (i) ruling out common causes of hypersomnolence, including mostly sleep apnea, insufficient sleep syndrome, psychiatric hypersomnia and narcolepsy; and (ii) obtaining objective EDS measures (mean latency at the multiple sleep latency test≤8min) or increased sleep time (sleep time>11h during a 18-24h bed rest). Treatment is similar to narcolepsy (except for preventive naps), including adapted work schedules, and off label use (after agreement from reference/competence centres) of modafinil, sodium oxybate, pitolisant, methylphenidate and solriamfetol. The diagnosis of KLS requires: (i) a reliable history of distinct episodes of one to several weeks; (ii) episodes contain severe hypersomnia (sleep>15h/d) associated with cognitive impairment (mental confusion and slowness, amnesia), derealisation, major apathy or disinhibited behaviour (hypersexuality, megaphagia, rudeness); and (iii) return to baseline sleep, cognition, behaviour and mood after episodes. EEG may contain slow rhythms during episodes, and rules out epilepsy. Functional brain imaging indicates hypoactivity of posterior associative cortex and hippocampus during symptomatic and asymptomatic periods. KLS attenuates with time when starting during teenage, including less frequent and less severe episodes. Adequate sleep habits, avoidance of alcohol and infections, as well as lithium and sometimes valproate (off label, after agreement from reference centres) help reducing the frequency and severity of episodes, and IV methylprednisolone helps reducing long (>30d) episode duration.

French consensus: Augmentation syndrome in restless legs syndrome.

Augmentation syndrome is one of the most severe complications of RLS. It is characterised by a worsening of treated symptoms; principally an increase in the severity of symptoms and an earlier onset time. Augmentation syndrome occurs primarily with dopaminergic treatments. It is crucial for the patient to be sufficiently well informed to prevent its occurrence and the prescription of too high doses of dopaminergic agonists avoided. In the presence of augmentation syndrome confirmed using the diagnostic criteria, the specialist treating the restless legs syndrome should quickly modify the patient's treatment. In this article, our expert group proposes a practical strategy for the diagnosis, prevention and treatment of augmentation syndrome.

French consensus. Idiopathic hypersomnia: Investigations and follow-up.

Idiopathic hypersomnia is a rare, central hypersomnia, recently identified and to date of unknown physiopathology. It is characterised by a more or less permanent, excessive daytime sleepiness, associated with long and unrefreshing naps. Night-time sleep is of good quality, excessive in quantity, associated with sleep inertia in the subtype previously described as "with long sleep time". Diagnosis of idiopathic hypersomnia is complex due to the absence of a quantifiable biomarker, the heterogeneous symptoms, which overlap with the clinical picture of type 2 narcolepsy, and its variable evolution over time. Detailed evaluation enables other frequent causes of somnolence, such as depression or sleep deprivation, to be eliminated. Polysomnography and multiple sleep latency tests (MSLT) are essential to rule out other sleep pathologies and to objectify excessive daytime sleepiness. Sometimes the MSLT do not show excessive sleepiness, hence a continued sleep recording of at least 24hours is necessary to show prolonged sleep (>11h/24h). In this article, we propose recommendations for the work-up to be carried out during diagnosis and follow-up for patients suffering from idiopathic hypersomnia.

Environmental risk factors for REM sleep behavior disorder: a multicenter case-control study.

OBJECTIVE: Idiopathic REM sleep behavior disorder is a parasomnia characterized by dream enactment and is commonly a prediagnostic sign of parkinsonism and dementia. Since risk factors have not been defined, we initiated a multicenter case-control study to assess environmental and lifestyle risk factors for REM sleep behavior disorder. METHODS: Cases were patients with idiopathic REM sleep behavior disorder who were free of dementia and parkinsonism, recruited from 13 International REM Sleep Behavior Disorder Study Group centers. Controls were matched according to age and sex. Potential environmental and lifestyle risk factors were assessed via standardized questionnaire. Unconditional logistic regression adjusting for age, sex, and center was conducted to investigate the environmental factors. RESULTS: A total of 694 participants (347 patients, 347 controls) were recruited. Among cases, mean age was 67.7 ± 9.6 years and 81.0% were male. Cases were more likely to smoke (ever smokers = 64.0% vs 55.5%, adjusted odds ratio [OR] = 1.43, p = 0.028). Caffeine and alcohol use were not different between cases and controls. Cases were more likely to report previous head injury (19.3% vs 12.7%, OR = 1.59, p = 0.037). Cases had fewer years of formal schooling (11.1 ± 4.4 years vs 12.7 ± 4.3, p < 0.001), and were more likely to report having worked as farmers (19.7% vs 12.5% OR = 1.67, p = 0.022) with borderline increase in welding (17.8% vs 12.1%, OR = 1.53, p = 0.063). Previous occupational pesticide exposure was more prevalent in cases than controls (11.8% vs 6.1%, OR = 2.16, p = 0.008). CONCLUSIONS: Smoking, head injury, pesticide exposure, and farming are potential risk factors for idiopathic REM sleep behavior disorder.

Does clinical rapid eye movement behavior disorder predict worse outcomes in Parkinson's disease?

Our purpose of this study was to investigate whether clinical rapid eye movement sleep behavior disorder (RBD) is indicative of more widespread degenerative changes in Parkinson's disease (PD), using a longitudinal cohort. In 2005 and 2007, we prospectively collected clinical and treatment characteristics of 61 consecutive patients with PD. The presence of RBD was assessed by spouse interview. Sixty-four percent of patients had clinical RBD in 2005, versus 52% of patients in 2007. The yearly incidence rate of clinical RBD onset was 9%, while clinical RBD disappeared in 14% of patients per year. The motor disability scores (when treated) were worse in patients with than without clinical RBD in 2005, but not in 2007. There was no difference between groups for frequency of freezing, falls, and hallucinations, or for scores on the depression scale, sleepiness scale, mini-mental state examination and frontal assessment battery at the beginning versus the end of the study. Patients with clinical RBD were disabled earlier than patients without RBD, but there was no specific worsening in the RBD group with time, either for motor or non-motor symptoms. The fluctuation and disappearance of clinical RBD in some patients may be due to functional abnormalities rather than lesions.

Propriospinal myoclonus revisited: Clinical, neurophysiologic, and neuroradiologic findings.

OBJECTIVE: The literature on propriospinal myoclonus (PSM) is poor and there are no systematic reviews of the subject. We sought to clarify the spectrum of PSM. METHODS: We first prospectively investigated all patients seen in our movement disorders clinic with a firm diagnosis of PSM between 2002 and 2007. All had a standardized interview, detailed clinical examination, laboratory investigations, comprehensive neurophysiologic examination, and spinal cord MRI, including diffusion tensor imaging with fiber tracking (DTI-FT). We also collected drug responses. Finally, we conducted a systematic review of the literature. RESULTS: We enrolled 10 patients meeting the strict criteria for PSM, and also analyzed data on 50 patients from 26 previous reports. PSM occurred predominantly in male and middle-aged patients. The typical clinical picture consisted of myoclonic jerks consistently involving abdominal wall muscles, which worsen in the lying position. A premonitory sensation preceding the jerks and wake-sleep transition phase worsening were frequent. Most patients had a myoclonic generator at the thoracic level, with a myoclonus duration between 200 msec and 2 s. An underlying cause was infrequently found. DTI-FT detected cord abnormalities all of our patients. CONCLUSION: The clinico-physiologic spectrum of propriospinal myoclonus (PSM) is homogenous. Involvement of the abdominal wall muscles, worsening in the lying position, premonitory sensation, and wake-sleep transition phase worsening are helpful clinical clues. Diffusion tensor imaging with fiber tracking appears more sensitive than conventional MRI for detecting associated microstructural abnormalities of the spinal cord. Symptomatic treatment of PSM is not straightforward, and clonazepam is reported to be the most effective drug. Zonisamide may be an interesting option.