Emerging psychiatric disorders in Kleine-Levin syndrome.

In Kleine-Levin syndrome (KLS), episodes of hypersomnia and cognitive, psychiatric and behavioural disturbances alternate with asymptomatic periods in adolescents. We evaluated whether psychiatric disorders would emerge during asymptomatic periods in a naturalistic, uncontrolled clinical cohort. Patients with primary KLS underwent psychiatric interviews at diagnosis and every year for 1-10 years, leading to diagnosis of former and present comorbid psychiatric disorders. Among the 115 patients (65.2% male and aged 16.1 ± 4.8 years at KLS onset), 19 (16.5%) had a history of psychiatric disorder prior to KLS onset, which persisted afterwards in 10. Twenty-five (21%) patients developed a new, comorbid psychiatric disorder 1-6 years after KLS onset, during 'asymptomatic' periods, including mood disorders (n = 14; including major depressive episodes, n = 8; recurrent depressive episodes, n = 2; bipolar I disorder, n = 1; dysthymic disorder, n = 1; adjustment disorder with depressive mood, n = 1; and mood disorder not otherwise specified, n = 1), anxiety disorders (n = 7), eating disorders (n = 2), psychotic disorders not otherwise specified (n = 2), schizoaffective disorder (n = 1) and cannabis dependence (n = 1). Six patients attempted suicide: two before and two after KLS onset, and two during episodes. Female sex, longer disease course, longer time incapacitated (356 ± 223 versus 155 ± 186 days) and more frequent psychiatric symptoms during episodes (but no family or personal history of psychiatric disorders) were associated with emerging psychiatric disorders. Contrary to the alleged benignity of KLS and normality between episodes, one KLS patient in five suffers from emerging psychiatric disorders. These disorders may depend on personal vulnerability and, most probably, on psychiatric symptoms during episodes.

Kleine-Levin syndrome in 120 patients: differential diagnosis and long episodes.

OBJECTIVE: Kleine-Levin syndrome is a rare disease characterized by recurrent episodes of hypersomnia with behavioral and cognitive disturbances. We aimed at describing the diagnosis procedure, risk factors, and severe forms. METHODS: In consecutive patients referred for suspected Kleine-Levin syndrome, we detailed differential diagnoses, and atypical and secondary cases, compared typical patients with healthy subjects, and examined the characteristics of patients with prolonged (>30 days) episodes. RESULTS: Among 166 referred patients, 120 had typical primary Kleine-Levin syndrome (syndrome secondary to brain diseases; n = 4, atypical syndrome, n = 7; differential diagnoses that were mostly psychiatric, n = 29; incomplete information, n = 6). The prevalence in France was 1.8 per million. The patients were often male (64%) and had more frequent birth and developmental abnormalities (45%) than controls (despite normal karyotypes), and most (80%) had teenage onset, with no difference between patients with prolonged (n = 34) and short (n = 85) episodes. In patients with prolonged episodes, the durations of the first episode (32 ± 33 vs 11 ± 6 days) and subsequent episodes were longer (mean episode duration = 23 ± 19 vs 10 ± 3 days) and the disease course tended to be longer (9 ± 6 vs 6 ± 4 years). During episodes, patients with prolonged episodes had shorter sleep time, higher levels of anxiety, increased agitation, and more feelings of disembodiment and amnesia. Between episodes, they were more tired, needed more naps, fell asleep more rapidly, and had higher anxiety/depression scores. INTERPRETATION: Mental disorders are frequent differential diagnoses of Kleine-Levin syndrome. One-third of patients have prolonged (>1 month) episodes with more frequent immediate and long-term consequences of the disease, prompting therapeutic trials.

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 minutes 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. CONCLUSIONS: 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 minutes after lights off time in clinical and criminal cases can be a parasomnia manifestation.

Do the EEG and behavioral criteria of NREM arousal disorders apply to sexsomnia?

STUDY OBJECTIVES: To establish whether the recent EEG and behavioral criteria of arousal disorders apply to sexsomnia. METHODS: EEG and behavioral markers upon N3 sleep interruptions in videopolysomnography were retrospectively compared in 24 participants with sexsomnia, 41 participants with arousals disorders, and 40 healthy controls. The specificity and sensitivity of previously suggested EEG and behavioral cutoffs for supporting arousal disorders diagnosis were measured in the sexsomnia vs. control groups. RESULTS: Participants with sexsomnia and arousals disorders showed a higher N3 fragmentation index, slow/mixed N3 arousal index, and number of eye openings during N3 interruptions than healthy controls. Ten (41.7%) participants with sexsomnia (vs. one sleepwalker and no control) displayed an apparently sexual behavior (masturbation, sexual vocalization, pelvic thrusting, and hand within the pajama) during N3 arousal. An N3 sleep fragmentation index ≥6.8/h of N3 sleep and two or more N3 arousals associated with eye opening was 95% specific but poorly (46% and 42%) sensitive for diagnosing sexsomnia. An index of slow/mixed N3 arousals ≥2.5/h of N3 sleep was 73% specific and 67% sensitive. An N3 arousal with trunk raising, sitting, speaking, showing an expression of fear/surprise, shouting, or exhibiting sexual behavior was 100% specific for a diagnosis of sexsomnia. CONCLUSIONS: In patients with sexsomnia, videopolysomnography based markers of arousal disorders are intermediate between healthy individuals and patients with other arousal disorders, supporting the concept of sexsomnia as a specialized, but less neurophysiologically severe, NREM parasomnia. Previously validated criteria for arousal disorders partially fit in patients with sexsomnia.

Comorbid parasomnias in narcolepsy and idiopathic hypersomnia: more REM than NREM parasomnias.

STUDY OBJECTIVES: To assess the frequency, determinants, and clinical impact of clinical rapid eye movement (REM) and non-REM (NREM) parasomnias in adult patients with narcolepsy type 1 (NT1), narcolepsy type 2 (NT2), and idiopathic hypersomnia compared with healthy controls. METHODS: Familial and past and current personal parasomnias were assessed by questionnaire and medical interviews in 710 patients (220 NT1, 199 NT2, and 221 idiopathic hypersomnia) and 595 healthy controls. RESULTS: Except for sleep-related eating disorder, current NREM parasomnias were rare in all patient groups and controls. Sleep-related eating disorder was more frequent in NT1 patients (7.9% vs 1.8% in NT2 patients, 2.1% in patients with idiopathic hypersomnia, and 1% in controls) and associated with disrupted nighttime sleep (odds ratio = 3.9) and nocturnal eating in full awareness (odds ratio = 6.9) but not with sex. Clinical REM sleep behavior disorder was more frequent in NT1 patients (41.4%, half being violent) than in NT2 patients (13.2%) and affected men more often than women (odds ratio = 2.4). It was associated with disrupted nighttime sleep, depressive symptoms, and antidepressant use. Frequent (> 1/week) nightmares were reported by 39% of patients with NT1, 29% with NT2, and 27.8% with idiopathic hypersomnia (vs 8.3% in controls) and were associated with depressive symptoms in narcolepsy. No parasomnia (except sleep-related hallucinations) worsened daytime sleepiness. CONCLUSIONS: In patients with central disorders of hypersomnolence, comorbid NREM parasomnias (except for sleep-related eating disorder) are rare and do not worsen sleepiness. In contrast, REM parasomnias are prevalent (especially in NT1) and are associated with male sex, disrupted nighttime sleep, depressive symptoms, and antidepressant use. CITATION: Leu-Semenescu S, Maranci J-B, Lopez R, et al. Comorbid parasomnias in narcolepsy and idiopathic hypersomnia: more REM than NREM parasomnias. J Clin Sleep Med. 2022;18(5):1355-1364.

A strange New Year's Eve: triggers in Kleine-Levin syndrome.

NONE: Kleine-Levin syndrome is a rare neurological disease of unknown cause beginning typically during adolescence, characterized by remittent-relapsing episodes of severe hypersomnia associated with cognitive and behavioral disturbances. Triggering factors at Kleine-Levin syndrome onset include infection, sleep deprivation, as well as alcohol, drug, and substance intake. A young woman had 6 episodes over 2 years, including hypersomnia, confusion, derealization, cognitive impairment, anxiety, feeling of being scrutinized, anorexia (and sweet craving once) but no hypersexuality. The first episode started after a party where she experienced a complete, 4-hour-long blackout despite moderate alcohol intake. The patient suspected having been poisoned. Twenty-five months after the party, when Kleine-Levin syndrome was eventually diagnosed, her long hair was analyzed and exogenous γ-hydroxybutyrate was found in the tips (corresponding to the party time). This case illustrates the interest of looking for γ-hydroxybutyrate in the hair when Kleine-Levin syndrome starts after a party.

Functional brain imaging using 18F-fluorodeoxyglucose positron emission tomography/computerized tomography in 138 patients with Kleine-Levin syndrome: an early marker?

Kleine-Levin syndrome is a rare disorder characterized by relapsing-remitting episodes of severe hypersomnia, cognitive impairment, apathy, derealization and behavioural disturbances. Between episodes, most patients experience normal sleep, mood and behaviour, but they may have some residual abnormalities in brain functional imaging; however, the frequency, localization and significance of abnormal imaging are unknown, as brain functional imaging have been scarce and heterogenous [including scintigraphy 18F-fluorodeoxyglucose positron emission tomography/computerized tomography (FDG-PET/CT) and functional MRI during resting state and cognitive effort] and based on case reports or on group analysis in small groups. Using visual individual analysis of 18F-fluorodeoxyglucose positron emission tomography/computerized tomography at the time of Kleine-Levin syndrome diagnosis, we examined the frequency, localization and clinical determinants of hypo- and hypermetabolism in a cross-sectional study. Among 179 patients with Kleine-Levin syndrome who underwent 18F-fluorodeoxyglucose positron emission tomography/computerized tomography, the visual analysis was restricted to the 138 untreated patients studied during asymptomatic periods. As many as 70% of patients had hypometabolism, mostly affecting the posterior associative cortex and the hippocampus. Hypometabolism was associated with younger age, recent (<3 years) disease course and a higher number of episodes during the preceding year. The hypometabolism was more extensive (from the left temporo-occipital junction to the entire homolateral and then the bilateral posterior associative cortex) at the beginning of the disorder. In contrast, there was hypermetabolism in the prefrontal dorsolateral cortex in half of the patients (almost all having concomitant hypometabolism in the posterior areas), which was also associated with younger age and shorter disease course. The cognitive performances (including episodic memory) were similar in patients with versus without hippocampus hypometabolism. In conclusion, hypometabolism is frequently observed upon individual visual analysis of 18F-fluorodeoxyglucose positron emission tomography/computerized tomography during asymptomatic Kleine-Levin syndrome periods; it is mostly affecting the posterior associative cortex and the hippocampus and is mostly in young patients with recent-onset disease. Hypometabolism provides a trait marker during the first years of Kleine-Levin syndrome, which could help clinicians during the diagnosis process.

IV steroids during long episodes of Kleine-Levin syndrome.

OBJECTIVE: To retrospectively compare the benefits (episode cessation) and risks of IV methylprednisolone (IV-MP) vs abstention during prolonged Kleine-Levin syndrome (KLS) episodes. METHODS: A total of 26 patients with KLS received 1 g/d IV-MP for 3 days during 1 to 6 episodes each (totaling 43 IV-MP sessions). The change of episode duration with IV-MP (vs previous episode duration) was compared with the change duration between 2 consecutive episodes in 48 untreated patients matched for age, sex, age at KLS onset, number of episodes, and disease duration (more treated than untreated patients had long episodes). RESULTS: Eleven patients (42.3%) had an episode that was at least 1 week shorter than the preceding one when they received IV-MP therapy, whereas shorter episodes were significantly less frequent (10.4%) in the untreated group. This benefit was more marked (65.5% responders, 12 fewer days in an episode vs 0 days in the untreated patients) when IV-MP was infused before the 10th day of the episode. Mild, transient adverse effects (insomnia, muscle pain, nervousness/restlessness, but no manic switching) were reported by 61.3% of patients. No specific responder profile was identified. CONCLUSION: In this open-labeled, naturalistic study, early IV-MP (following the protocol for multiple sclerosis relapses) had a good benefit/risk ratio during KLS episodes in patients with long episodes (with half of the patients having an early cessation of episodes). CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with long episodes of KLS, IV steroids decrease the duration of KLS episodes.

Sleepiness in sleepwalking and sleep terrors: a higher sleep pressure?

OBJECTIVE: To identify the determinants of excessive daytime sleepiness in adults with sleepwalking or sleep terrors (SW/ST). METHODS: We collected the charts of all consecutive adult patients admitted from 2012 to 2014 for SW/ST. They had completed the Paris Arousal Disorders Severity Scale and the Epworth Sleepiness Scale, and had undergone one (n = 34) or two consecutive (n = 124) nocturnal videopolysomnographies. The demographic, clinical, and sleep determinants of excessive daytime sleepiness (defined as an Epworth Sleepiness Scale score of greater than 10) were analyzed. RESULTS: Almost half (46.8%) of the 158 adult patients with SW/ST reported excessive daytime sleepiness. They had shorter sleep onset latencies (in night 1 and night 2), shorter REM sleep latencies, longer total sleep time, and higher REM sleep percentages in night 2, but no greater clinical severity of the parasomnia than patients without sleepiness. The level of sleepiness correlated with the same measures (sleep onset latency on both nights, REM sleep onset latency, and total sleep time in night 2), plus the latency to N3. In the regression model, higher sleepiness was determined by shorter sleep onset latency on night 1, lower number of awakenings in N3 on night 1, and higher total sleep time on night 2. CONCLUSION: Daytime sleepiness in patients with SW/ST is not the consequence of disturbed sleep but is associated with a specific polygraphic phenotype (rapid sleep onset, long sleep time, lower numbers of awakenings on N3) that is suggestive of a higher sleep pressure that may contribute to incomplete arousal from N3.

Familial Kleine-Levin Syndrome: A Specific Entity?

STUDY OBJECTIVES: Kleine-Levin syndrome (KLS) is a rare, mostly sporadic disorder, characterized by intermittent episodes of hypersomnia plus cognitive and behavior disorders. Although its cause is unknown, multiplex families have been described. We contrasted the clinical and biological features of familial versus sporadic KLS. METHODS: Two samples of patients with KLS from the United States and France (n = 260) were studied using clinical interviews and human leukocyte antigen (HLA) genotyping. A multiplex family contained two or more first- or second-degree affected relatives (familial cases). RESULTS: Twenty-one patients from 10 multiplex families (siblings: n = 12, including two pairs of monozygotic twins; parent-child: n = 4; cousins: n = 2; uncle-nephews: n = 3) and 239 patients with sporadic KLS were identified, yielding to 4% multiplex families and 8% familial cases. The simplex and multiplex families did not differ for autoimmune, neurological, and psychiatric disorders. Age, sex ratio, ethnicity, HLA typing, karyotyping, disease course, frequency, and duration of KLS episodes did not differ between groups. Episodes were less frequent in familial versus sporadic KLS (2.3 ± 1.8/y versus 3.8 ± 3.7/y, P = 0.004). Menses triggered more frequently KLS onset in the nine girls with familial KLS (relative risk, RR = 4.12, P = 0.03), but not subsequent episodes. Familial cases had less disinhibited speech (RR = 3.44, P = 0.049), less combined hypophagia/hyperphagia (RR = 4.38, P = 0.006), more abrupt termination of episodes (RR = 1.45, P = 0.04) and less postepisode insomnia (RR = 2.16, P = 0.008). There was similar HLA DQB1 distribution in familial versus sporadic cases and no abnormal karyotypes. CONCLUSION: Familial KLS is mostly present in the same generation, and is clinically similar to but slightly less severe than sporadic KLS.

Lithium therapy in Kleine-Levin syndrome: An open-label, controlled study in 130 patients.

OBJECTIVE: To compare the benefits and risks of lithium therapy vs abstention/other treatments in Kleine-Levin syndrome (KLS). METHODS: In a KLS cohort followed in a single center, 130 patients regularly took lithium carbonate (median dose 1,000 mg/day; n = 71; 40 children), valproate (n = 5), contraceptive pill (n = 5), or no treatment (n = 49). The disease characteristics (frequency, mean, and longest durations of episodes, time incapacitated per year) were compared before and after follow-up in the lithium vs abstention groups. RESULTS: The time between KLS onset and therapeutic onset was 69 ± 92 months. The patients were then followed up for a mean of 21.5 ± 17.8 months. Before treatment, the 71 patients treated with lithium tended to have a higher frequency of episodes per year (3.8 ± 2.9 vs 2.9 ± 2.6) and had a longer time spent incapacitated (57 ± 51 vs 37 ± 35 days) than the untreated patients. The mean (-8 ± 20 vs 2 ± 13 days) and longest (-18 ± 35 vs -5 ± 13) episode duration, the time spent incapacitated (-37 ± 65 days vs -10 ± 38), as well as the frequency of episodes per year (-2.6 ± 2.9 vs 1.3 ± 2.78) decreased significantly more in the treated than in the untreated patients. Side effects (reported by 50% of the patients) were mild and classical with lithium (tremor, increased drinking, diarrhea, and subclinical hypothyroidism). CONCLUSIONS: In this large, prospective, open-label, controlled study, the benefit/risk ratio of lithium therapy is superior to that of abstention, supporting the concept that lithium has anti-inflammatory/neuroprotective effects. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with KLS, lithium decreases the frequency and duration of KLS episodes.