Multiple Sleep Latency Test Results Research Articles

Allowing ad libitum sleep during overnight polysomnography affects Multiple Sleep Latency Test results in patients being assessed for hypersomnolence.

The Multiple Sleep Latency Test (MSLT) is a key diagnostic component in the diagnosis of central disorders of hypersomnolence. Due to time constraints, it is common practice to wake patients at a standard time from overnight polysomnography (PSG) prior to the MSLT. This has the potential to influence MSLT results due to sleep deprivation. We describe the impact of allowing ad libitum sleep on the night prior to the MSLT in patients being assessed for hypersomnolence. A total of 580 consecutive patients undergoing PSG/MSLT for assessment of hypersomnolence were analyzed: 290 either side of a change in laboratory protocol that allowed patients ad libitum sleep during the PSG, rather than being woken at a prespecified time. Baseline characteristics, PSG and MSLT results were compared between the groups. Groups were similar at baseline, other than there being more females in the ad libitum group. After adjusting for confounding variables, patients allowed ad libitum sleep had later sleep offset time (+58.7 minutes; P < .001), longer PSG total sleep time (+47.8 minutes; P < .001), longer MSLT mean sleep latency (+1.3 minutes; P = .002), and 23% fewer MSLT with mean sleep latency less than 8 minutes (P = .004) when compared with patients who were woken at a standard time. The common practice of waking patients from their PSG at a standard time has the potential to curtail sleep and affect MSLT results by reducing mean sleep latency. Patients being assessed for hypersomnolence should be allowed ad libitum sleep during the PSG on the night prior to their MSLT. Frenkel S, Amaranayake A, Molesworth C, Orellana L, Southcott AM. Allowing ad libitum sleep during overnight polysomnography affects Multiple Sleep Latency Test results in patients being assessed for hypersomnolence. J Clin Sleep Med. 2024;20(12):1937-1943.

The effects of daylight duration on the multiple sleep latency test (MSLT) results: A pilot study

ObjectiveMSLT results are known to be affected by multiple factors including sleep time, frequency of nighttime arousals, and medications intake. Although being the main synchronizer of sleep and wakefulness, daylight duration effects on MSLT have not been examined. Burlington, Vermont, USA experiences great variations in daylight duration, ranging from 8 h 50 min to 15 h 33 min of daylight. The aim of this study was to test the hypothesis that there would be photoperiod duration effects on MSLTs performed during short daylight (short daylight studies, SDS) vs. long daylight (long daylight studies, LDS) from 2013 to 2023 in our sleep laboratory. methodsWe identified and analyzed 37 SDS (daylight 530–560 min) and 36 LDS (daylight 903–933 min) from our database. Groups of SDS and LDS results were compared using non-paired student T test, Chi-Square and non-parametric Mann Whitney U Test. ResultsAverage daylight duration was 15 h 18 ± 14.6 min for LDS and 8 h 57 ± 18 min for SDS. Two groups did not differ in terms of the age, gender, BMI and race of patients studied. Mean total sleep time and sleep efficiency during PSG preceding MSLT, and MSLT mean sleep onset latency did not significantly differ for the two groups. However, SDS MSLT naps had significantly more sleep onset REM periods (SOREMP), and distribution of the number of SOREMP captured during MSLT was different for SDS and LDS groups. Differences of SDS and LDS results did not relate to sleep architecture of the overnight PSG as analysis of sleep and REM latency and relative percentages of N1, N2, REM, and N3 was not significantly different between SDS and LDS. The two groups showed difference in arousal indexes during N1 and REM sleep. ConclusionsDaylight duration may impact MSLT results and should probably be accounted for in MSLT interpretation. Attention to photoperiod could be considered in MSLT guidelines, if our results are replicated in larger samples.

Sleepy Kids: are the current diagnostic criteria for multiple sleep latency tests enough?

Excessive daytime sleepiness (EDS) is common in childhood and is currently quantified using adult criteria on a multiple sleep latency test (MSLT). This study aimed to describe paediatric MSLT results, particularly focussing on a previously proposed alternative mean sleep latency (MSL) threshold for children of 12 min, and assess the impact of a 5th nap. We performed a retrospective analysis of MSLTs at a single paediatric centre from 2004 to 2021. Narcolepsy was defined as a mean sleep latency (MSL) ≤8min with ≥2 sleep onset REM (SOREM) periods. Idiopathic Hypersomnia (IH) was defined as a MSL ≤8min with <2 SOREMs. An ambiguous MSLT result was defined as a MSL 8–12min and/or ≥2 SOREM periods. Of 214 MSLTs [50 % female, median age 14.0y (range 3.3–20.1y)], narcolepsy was diagnosed in 48 (22 %), IH in 22 (10 %) and the result was ambiguous in 44 (21 %). Those with ambiguous MSLT results were older (15.6 vs 13.4y, p = 0.006) with a higher proportion of females (61 % vs 35 %, p = 0.01) in comparison to the narcolepsy group. A 5th nap was performed in 60 (28 %) of MSLTs and only changed the outcome in one case. In conclusion, MSLT results are borderline in 21 % of paediatric cases, suggesting that current adult diagnostic criteria may miss narcolepsy and IH in children. A 5th nap usually makes no difference or increases the MSL, suggesting that a four nap MSLT protocol could be used apart from rare cases where the result is borderline after the 4th nap.

Role of Daytime Continuous Polysomnography in the Diagnosis of Pediatric Narcolepsy Type 1.

Narcolepsy type 1 (NT1) is still largely underdiagnosed or diagnosed too late in children. Difficulties in obtaining rapid and reliable diagnostic evaluations of the condition in clinical practice partially explain this problem. Predictors of NT1 include cataplexy and sleep-onset REM periods (SOREMPs), documented during nocturnal polysomnography (N-PSG) or through the multiple sleep latency test (MSLT), although low CSF hypocretin-1 (CSF hcrt-1) is the definitive biological disease marker. Obtaining reliable MSLT results is not always feasible in children; therefore, this study aimed to validate daytime continuous polysomnography (D-PSG) as an alternative diagnostic tool. Two hundred consecutive patients aged younger than 18 years (112 with NT1; 25 with other hypersomnias, including narcolepsy type 2 and idiopathic hypersomnia; and 63 with subjective excessive daytime sleepiness) were randomly split into 2 groups: group 1 (n = 133) for the identification of diagnostic markers and group 2 (n = 67) for the validation of the detected markers. The D-PSG data collected included the number of spontaneous naps, total sleep time, and the number of daytime SOREMPs (d-SOREMP). D-PSG data were tested against CSF hcrt-1 deficiency (NT1 diagnosis) as the gold standard using receiver operating characteristic (ROC) curve analysis in group 1. ROC diagnostic performances of single and combined D-PSG parameters were tested in group 1 and validated in group 2. In group 1, the areas under the ROC curve (AUCs) were 0.91 (95% CI 0.86-0.96) for d-SOREMPs, 0.81 (95% CI 0.74-0.89) for the number of spontaneous naps, and 0.70 (95% CI 0.60-0.79) for total sleep time. A d-SOREMP count ≥1 (sensitivity of 95% and specificity of 72%), coupled with a diurnal total sleep time above 60 minutes (sensitivity of 89% and specificity of 91%), identified NT1 in group 1 with high reliability (area under the ROC curve of 0.93, 95% CI 0.88-0.97). These results were confirmed in the validation group with an AUC of 0.88 (95% CI 0.79-0.97). D-PSG recording is an easily performed, cost-effective, and reliable tool for identifying NT1 in children. Further studies should confirm its validity with home D-PSG monitoring. These alternative procedures could be used to confirm NT1 diagnosis and curtail diagnostic delay.

Associations between psychiatric comorbid disorders and executive dysfunctions in hypocretin-1 deficient pediatric narcolepsy type1

Objective/BackgroundPsychiatric symptoms and cognitive deficits add significantly to impairment in academic achievement and quality of life in patients with narcolepsy. The primary aim of this study was to evaluate the prevalence of psychiatric disorders and executive dysfunctions, secondly to explore the association between psychiatric comorbidity, executive dysfunctions, subjective and objective sleep measures, and severity of cerebrospinal fluid (CSF) hypocretin-1 deficiency in pediatric narcolepsy type 1 (PNT1). Patients/MethodsCross-sectional study of 59 consecutively included PNT1 patients (age: 6-20 years; 34:25 girls: boys; 54/59 H1N1 (Pandemrix®)-vaccinated). Core narcolepsy symptoms including subjective sleepiness, polysomnography and multiple sleep latency test results, CSF hypocretin-1 levels, psychiatric disorders (by semistructured diagnostic interview Kaufmann Schedule for Affective Disorders and Schizophrenia Present and Lifetime version (KSADS)), and executive dysfunction (by Behavior Rating of Executive Function (BRIEF)) were assessed. Results52.5% of the patients had one or more psychiatric comorbid disorder, and 64.7% had executive dysfunction in a clinically relevant range, with no sex difference in prevalence, while older age was associated with poorer executive function (p=0.013). Having any psychiatric comorbid disorder was associated with poorer executive functions (p=0.001). CSF hypocretin-1 deficiency severity was significantly associated with presence of psychiatric comorbidity (p=0.022) and poorer executive functions (p=0.030), and poorer executive functions was associated with subjective sleepiness (p=0.009). ConclusionsThe high occurrence of, and association between, psychiatric comorbidity and executive dysfunction underlines the importance of close attention to both these comorbidities in clinical care of NT1.

Challenges in Diagnosing Narcolepsy and Idiopathic Hypersomnia

Narcolepsy and idiopathic hypersomnia are central disorders of hypersomnolence accompanied by excessive daytime sleepiness, which are not caused by nocturnal sleep disturbance, sleep deficiency, or circadian rhythm sleep disorders. Several studies have questioned the repeatability of the Multiple Sleep Latency Test (MSLT) in type 2 narcolepsy (NT2) patients. After two or more repeated MSLTs, the diagnosis of type 1 narcolepsy (NT1) is maintained in more than 90% of cases, while only half of the NT2 patients retain their original diagnosis. The diagnosis of NT2 may shift to idiopathic hypersomnia based on the MSLT results, making the differential diagnosis of NT2 and idiopathic hypersomnia particularly challenging. Therefore, this study suggests the need for new tests in addition to the MSLT for diagnostic consistency in NT2 and idiopathic hypersomnia.

Moving toward standardization: physician reporting of sleep studies.

Lastra AC, Ingram D, Park J, etal. Moving toward standardization: physician reporting of sleep studies. J Clin Sleep Med. 2023;19(3):595-603.

Subjective-objective sleepiness discrepancy in adult-onset myotonic dystrophy type 1.

Subjective-objective sleepiness discrepancy in adult-onset myotonic dystrophy type 1.

P003 The impact of forced wake from overnight polysomnography on multiple sleep latency test results

Abstract Introduction The multiple sleep latency test (MSLT) is used to diagnose disorders of hypersomnolence. Although internationally-recognised protocols do not stipulate whether patients should be woken from the preceding overnight polysomnography (PSG), many labs wake their patients for logistic reasons. This study analyses the impact on PSG and MSLT parameters of forced wake (FW) from the overnight PSG compared with unrestricted sleep (US). Methods 400 consecutive patients (FW=200; US=200) undergoing PSG/MSLT were included and the following parameters were compared: Epworth Sleepiness Scale (ESS), Morningness-Eveningness Questionnaire score (MEQ), PSG total sleep time (TST), wake-up time from the PSG, overall MSLT sleep latency (MSL), individual nap latencies (SLNap 1–4), number of MSLT naps with sleep-onset REM periods (#SOREMP), and percentage of MSLTs with overall MSL&amp;lt;8 minutes (%MSLT&amp;lt;8). Results The 2 groups were well-matched for ESS and MEQ. The FW group had more males (49% vs 39%). When compared to FW, patients with US had longer TST (+38 minutes; p=&amp;lt;0.0001), later wake-up time (+52 minutes; p&amp;lt;0.0001), longer MSL (+1.9 minutes; p=0.0049), 50% fewer #SOREMP (p=0.0224), and 16% fewer %MSLT&amp;lt;8 (p=0.0018). SLNap1 increased by 1.5 minutes (p=0.0623), SLNap2 increased by 2.0 minutes (p=0.0067), SLNap3 increased by 0.75minutes (p=0.0533) and SLNap4 increased by 2.5 minutes (p=0.0059). Discussion Allowing patients to have unrestricted sleep on the night prior to the MSLT resulted in significantly longer TST, longer sleep latencies during the MSLT, fewer SOREMP and fewer tests with MSL&amp;lt;8 minutes. International protocols should stipulate unrestricted sleep on the PSG prior to the MSLT to improve diagnostic accuracy.

P034 Inter-scorer concordance impacts MSLT results

Abstract Introduction A retrospective study on the effect of inter-scorer concordance and impact of analysing polysomnography (PSG) data prior to the Multiple Sleep Latency Test (MSLT) on clinical interpretation of Narcolepsy (N) and Idiopathic Hypersomnolence (IH). Methods Data of four individuals was randomly selected from a cohort of patients that participated in MSLT studies. De-identified MSLT fragments from four nap periods (n=16) were scored in two groups: analysis of PSG conducted prior to the respective MSLT fragments, and analysis without access to prior PSG. Individual scorers were compared to a master score set, by consensus from two experienced sleep scientists. Spearman correlation and percentage agreement statistics were applied to calculate the inter-scorer concordance in sleep latency and REM latency. Mann-Whitney test was utilised to assess differences between the two groups. A positive result was assigned as: mean (n=4) sleep latency of &amp;lt;10min (IH), and mean (n=4) sleep latency of &amp;lt;8min including (n=2) SOREMs (N). Results From 16 sets of data, four false positive results were identified when PSG was not analysed prior to scoring the MSLT fragments. Additionally, statistically significant differences were present when PSG analysis was conducted prior to scoring MSLT sleep latency and REM latency data. Discussion These results support a recommendation that PSG analysis (sleep and REM latency) should be encouraged prior to MSLT studies and performed by the same sleep scientist. Furthermore, including MSLT data in intra-lab concordance activities is important, particularly in relation to medical interpretation and practice.

606 Incidence &amp; Influence of Drug Screening in Children with Hypersomnolence During MSLT: Analysis of the Children’s Wisconsin Cohort

Abstract Introduction The Multiple Sleep Latency Test (MSLT) is a validated test for evaluation of hypersomnolence in children and adults. AASM practice parameters recommend performing urine drug screens (UDS) in patients undergoing MSLT to identify substances that alter MSLT results. The study aims are to determine the incidence of positive UDS and their influence on MSLT variables in a cohort of children evaluated for hypersomnolence. Methods All children undergoing an MSLT in Children’s Wisconsin sleep laboratory over an 8-year period (11/1/2012 to 9/30/2020) were included in this retrospective chart review study. Clinical and demographic data, including UDS results were manually abstracted. Record validation conducted by random allocation. Data were summarized as median and IQR or n (%). Chi-square test or Fisher’s exact test were used to examine associations between categorical variables. Results 236 children completed an MSLT. The sample had a median age of 14.1 (IQR 10.5–16.2) years (50.9% female; 63.1% Caucasian). Narcolepsy I (“N1”; n=14; 5.9%), Narcolepsy II (“N2”; n=56; 23.7%), Idiopathic Hypersomnia (“IH”; n=39; 16.5%) were frequently diagnosed. Most children (97.9%) completed a UDS; 60.2% tested positive. Common substances found on UDS were caffeine (62.6%), OTC medications (40.3%), and prescription medications (33.8%), however nicotine (14.3%) and cannabis (5.8%) were also seen. Caffeine was commonly found in those diagnosed with N1 (70%), N2 (69.4%), and IH (54.2%). Fewer children diagnosed with narcolepsy were positive for prescription medications compared to those diagnosed with IH (21.7% versus 41.7%) although results did not reach significance (p=0.08). No child with N1 tested positive for prescription medications. ≥2 substances were found in 43.2% of positive drug screens. OTC medications and caffeine were most commonly co-occurring (23%); OTC analgesics being the most common OTC medication. No association between positivity for &amp;gt;2 substances and sleep diagnosis was found (p=0.5). Conclusion More than half of children undergoing an MSLT had a positive UDS for &amp;gt;1 substance. The impact of these substances on PSG/MSLT parameters (total sleep time, mean sleep onset latency, sleep onset REM periods) is under investigation through additional analysis. Based on the above data our findings support the AASM guidelines of children obtaining a UDS on the day of MSLT. Support (if any):

Validity of the Pupillographic Sleepiness Test for the diagnosis of daytime sleepiness in children and adolescents and its relationship to sleepiness-associated outcomes

ObjectivesTo report validation data for the Pupillographic Sleepiness Test (PST) in children and adolescents, evaluate its applicability for diagnosing excessive daytime sleepiness and its relationship to sleepiness-associated outcomes. MethodsA cross-sectional diagnostic test accuracy study was performed. Patients underwent three PST at 9 a.m. (T1), 11 a.m. (T2) and 1 p.m. (T3) plus the Multiple Sleep Latency Test (MSLT) on a single day. Additionally, two neurocognitive tests were performed and three questionnaires about quality of life, sleep-related self-efficacy and behavioural aspects completed. Gender-stratified z-values of the natural logarithm of the Pupillary Unrest Index (z-lnPUI) were correlated to Sleep Latency (SL) and Mean Sleep Latency (MSL) and to variables of neurocognitive tests and questionnaires using Spearman's rank correlation. Cut-off values were determined by receiver operating characteristic (ROC) analysis. Results47 patients were recruited (median 10.6 years, range 6–18). Correlation between z-lnPUI and SL was rT1 = −0.373 (p = 0.011); rT2 = −0.320 (p = 0.028) and rT3 = −0.336 (p = 0.022). Correlation between z-lnPUI and MSL was rT1 = −0.338 (p = 0.020); rT2 = −0.202 (p = 0.173); rT3 = −0.117 (p = 0.433). ROC analysis showed an area under the curve of 90.7% and PUI cut-off values of 12.6 mm/min (boys) and 11.6 mm/min (girls). There were moderate correlations between z-lnPUIT1 and reaction time and omission errors in neurocognitive tests (r = 0.394, p = 0.007 and 0.391, p = 0.008). ConclusionsWe found satisfactory correlations between PST and MSLT results. The z-lnPUIT1 was related to MSL and objective measures of attention ability. Given this accuracy, the PST may be used as a screening tool for evaluating daytime sleepiness in children and adolescents. Corresponding gender-related reference values are now available.

False-positive cases in multiple sleep latency test by accumulated sleep debt.

PurposeMultiple sleep latency test (MSLT) is performed as objective assessment of sleepiness, on the following day after polysomnography (PSG). In most clinics, patients are required to stay for 2 days. However, if patients have chronic sleep debt before the examination, even if they get adequate nocturnal sleep during the initial PSG, their sleep debt would not be fully resolved, affecting MSLT results. This may lead to improper administration of psycho‐stimulant medication. To clarify the sleep debt for the patients who showed short sleep latencies, we compared the mean sleep latencies of MSLTs.MethodsTwelve hypersomnolent males, who underwent MSLTs (1st MSLT with 1 night and 2nd MSLT with more than 3 nights), were enrolled. We selected these cases based on the longer total sleep time on PSG night compared to the mean total sleep time on pre‐examination sleep logs and shortened sleep latencies on PSG. To evaluate the effect of the sleep debt for the patients who showed short sleep latencies, we extended their hospitalization or re‐hospitalized them.ResultsThe mean sleep latency of 1st MSLT was 5.8 minutes and that of 2nd was 13.9 minutes (P < .001). Among these 12 cases, 5 cases altered from short to normal sleep latencies at the 2nd MSLT. These 5 cases were prevented from over‐diagnoses by the extension of evaluations.ConclusionsThe sleep debt may produce false‐positive results when patients are examined by standard PSG and MSLT. Accumulation of sleep debt will cause shortened sleep latencies in the following nights. Patients should be advised to extend their hospitalization before PSG and MSLT to reduce the chronic sleep debt for accurate diagnosis of hypersomnia.

P.672 Physical, physiological and biochemical parameters of adults with schizophrenia: Data from cognitive rehabilitation and training with exercise for schizophrenia study

Exercise training has been shown to improve learning and memory, and to protect against the negative impact of sleep deprivation. The aim of this study was to investigate the effects of seven weeks of moderate- and high-intensity interval exercise training on vigilance/sustained attention, inhibition processes and working memory during 40-h total sleep deprivation (TSD) in 16 healthy young men.The subjects were evaluated before (Baseline, BAS) and during TSD, and the day after a night of recovery sleep (Recovery, REC).Exercise training significantly decreased errors and increased speed assessed by the psychomotor vigilance task (PVT) during TSD and REC while no difference was found in executive inhibition (Go–noGo task) and working memory (2-Back task) performances. The multiple sleep latency test results were higher during BAS and REC at Post-exercise training, and no difference occurred in subjective sleepiness and daytime microsleeps over the 40-h TSD. The PVT speed was positively correlated with maximal oxygen consumption and maximal aerobic power measured before entry in the in-laboratory TSD protocol, and stage 3 sleep duration measured during the first night in the in-laboratory TSD protocol (N-1). Exercise training effects on sleep were found during the night recovery with lower stage-3 sleep and higher rapid eye movement (REM) sleep durations. An exercise training effect was also found on free insulin-like growth factor I levels with lower levels during TSD at Post-exercise training.In healthy young men, exercise training reduced sleep pressure at baseline and protected against sustained attention deficits induced by TSD with persistent effect after one night of recovery sleep. Nevertheless, exercise training was not effective in reducing deficits in executive inhibition and working memory induced by TSD.

Beneficial effects of exercise training on cognitive performances during total sleep deprivation in healthy subjects

ObjectiveExercise training has been shown to improve learning and memory, and to protect against the negative impact of sleep deprivation. The aim of this study was to investigate the effects of seven weeks of moderate- and high-intensity interval exercise training on vigilance/sustained attention, inhibition processes and working memory during 40-h total sleep deprivation (TSD) in 16 healthy young men. MethodsThe subjects were evaluated before (Baseline, BAS) and during TSD, and the day after a night of recovery sleep (Recovery, REC). ResultsExercise training significantly decreased errors and increased speed assessed by the psychomotor vigilance task (PVT) during TSD and REC while no difference was found in executive inhibition (Go–noGo task) and working memory (2-Back task) performances. The multiple sleep latency test results were higher during BAS and REC at Post-exercise training, and no difference occurred in subjective sleepiness and daytime microsleeps over the 40-h TSD. The PVT speed was positively correlated with maximal oxygen consumption and maximal aerobic power measured before entry in the in-laboratory TSD protocol, and stage 3 sleep duration measured during the first night in the in-laboratory TSD protocol (N-1). Exercise training effects on sleep were found during the night recovery with lower stage-3 sleep and higher rapid eye movement (REM) sleep durations. An exercise training effect was also found on free insulin-like growth factor I levels with lower levels during TSD at Post-exercise training. ConclusionsIn healthy young men, exercise training reduced sleep pressure at baseline and protected against sustained attention deficits induced by TSD with persistent effect after one night of recovery sleep. Nevertheless, exercise training was not effective in reducing deficits in executive inhibition and working memory induced by TSD.

Demographic and nap-related variance of the MSLT: results from 2,498 suspected hypersomnia patients: Clinical MSLT variance

ObjectiveThe purpose of this study was to enhance our understanding of clinical trends in sleep and rapid eye movement (REM) propensity on the multiple sleep latency test (MSLT). Demographic variables of interest included early childhood/advanced age, gender, race, and REM-suppressant use. MethodsNocturnal sleep studies and 5-nap MSLTs were retrieved from a large repository of deidentified studies from various US sleep clinics between 2007 and 2015. Studies were signal processed, human-edited, and underwent rigorous quality assurance for inclusion. ResultsThe final sample consisted of N = 2498 MSLTs (24.2% Black; 34.2% Men; Age 4–89). In adults (age ≥ 21), sleep propensity modestly decreased across nap (90% at nap 1 to 80% at nap 5; p < 0.001). Children ≤12 years were least likely to fall asleep on any nap (∼55% at nap 5). REM propensity troughed at nap 4 (13%) and varied with age. Advanced age (≥60 years; OR: 0.28, p < 0.001), REM-suppressant use (OR:0.52, p < 0.001), and female sex (men OR: 1.48, p = 0.012) was associated with a decreased proportion of ≥2 REMs in adjusted logistic models. Children often demonstrated only 1 REM and generally had long sleep latencies, yielding a low proportion of MSLTs consistent with narcolepsy (11.0% vs. 19.2% and 16.8% in those between 13–20 and 21–59, respectively; p = 0.003). ConclusionsMSLT outcomes vary greatly across age, gender, and use of psychotropic medication. Demographic variance should be considered when interpreting MSLT results. Robust age effect question the appropriateness of the MSLT as currently designed and implemented for children and older adults.

A Longitudinal Follow-Up Study on Multiple Sleep Latency Test and Body Mass Index of Patients With Narcolepsy Type 1 in Korea.

Narcolepsy is a chronic disorder with numerous adverse long-term consequences including increased obesity, high mortality rates, and decreased quality of life. With emerging attention to the long-term course of the disorder and importance of accurate diagnosis, the diagnostic stability of the Multiple Sleep Latency Test (MSLT)-the mostly frequently used test to identify narcolepsy-is often challenged. In this study, we compared the baseline and follow-up demographic characteristics and body mass index (BMI) of patients with narcolepsy type 1. Moreover, MSLT results from repeated tests conducted on 48 patients with narcolepsy type 1 were compared, with mean follow-up of approximately 10 years. BMI from the baseline to the follow-up visit was significantly increased in the participants. There were no significantly different parameter changes in MSLT results. MSLT has good test-retest validity in patients with narcolepsy type 1. Close surveillance for the detection and management of obesity is warranted in clinical settings.

The Perception and Attention Functions test battery as a measure of neurocognitive impairment in patients with suspected central disorders of hypersomnolence.

The aim of the current study was to evaluate an attention test as a discriminative tool to measure neurocognitive impairment in patients with disorders of hypersomnolence. Chronic excessive daytime sleepiness is the main symptom in central disorders of hypersomnolence. For diagnostic purposes and treatment evaluation, reliable assessment of excessive daytime sleepiness is required. Thirty-six patients with central disorders of hypersomnolence were compared with 20 healthy controls. All participants performed the 'Perception and Attention Functions' (WAF) of the Vienna Test System. Patients underwent polysomnography, Multiple Sleep Latency Test and Maintenance of Wakefulness Test. Patients were divided into two groups: (i) patients who met the criteria of disorder of hypersomnolence (objective excessive daytime sleepiness); and (ii) patients with subjective excessive daytime sleepiness, i.e. with normal Multiple Sleep Latency Test results. Group 1 consisted of 23 patients with objective excessive daytime sleepiness (11 with idiopathic hypersomnia, nine with narcolepsy type 1, three with narcolepsy type 2); group 2 included 13 patients with subjective excessive daytime sleepiness. The results showed cognitive impairment in patients with objective excessive daytime sleepiness and even in patients with subjective excessive daytime sleepiness. WAF tests identified distinct attention profiles in patients with narcolepsy type 1, idiopathic hypersomnia/narcolepsy type 2, and patients with subjective excessive daytime sleepiness. WAF test measures correlated with Maintenance of Wakefulness Test and the Epworth Sleepiness Scale, but not with Multiple Sleep Latency Test and the Fatigue Severity Scale. In conclusion, the multidimensional WAF test battery detects cognitive impairment even in patients that complain of excessive daytime sleepiness but have normal Multiple Sleep Latency Test results. WAF tests offer valuable information that adds to the existing polysomnographic measures in discriminating patients with different types of chronic excessive daytime sleepiness. The results provide new insights into cognitive dysfunction underlying different types of chronic excessive daytime sleepiness.

Clinical case: Ten-year-old girl with impossibility to wake up

The impossibility and difficulty to wake up is a sign that can appear in several sleep disorders in children: Delayed Sleep-Phase Syndrome, insomnia, Restless Legs Syndrome, Inadequate Sleep Hygiene and others like neuropsychiatric sleep disorders. CLINICAL CASE Ten-year-old girl with suspected diagnosis of epilepsy with daily episodes of hypotonia, repetitive speech and impossibility to wake up. Several EEG studies and cranial NMR were normal. Treatment with Valproate was initiated without clinical changes, so the treatment was suspended and parasomnia diagnosis was given. She was referred to sleep disorders clinic because the impossibility to wake up with school absentism. Her mother reports remarkable leg movements during first part of the night. Polysomnography and Multiple Sleep Latency Test, serum iron and ferritine level and Actigraphy were requested. Polysomnography with Multiple Sleep Latency Test results were a low increase of the Leg Movements Index in both legs regarding the diagnosis of mild Restless Legs Syndrome. Narcolepsy and infantil sleep apnea disorder were rejected. Actigraphy showed signs of Delayed Sleep-Phase Syndrome. Treatment with two drops of clonazepam before going to bed, had given good results, reducing the difficulty to wake up and improving her school performance. Restless Legs Syndrome in children can give different clinical presentation, so insomnia and difficulty to wake up must be considered in differential diagnosis. Servicio de Neurofisiología Clínica, Hospital Virgen de las Nieves.

What Has Been Going on With My Sleep After My Car Accident?

INTRODUCTION: Hypnagogic hallucinations are hallucinatory experiences that accompany the onset of awakening, they can occur in certain states, such as sleep deprivation and conditions such as narcolepsy. Main neural structures responsible for muscle atonia in REM sleep are dorsolateral portions of the pons and brainstem, cholinergic and cholinoceptive REM sleep-on neurons, monoaminergic REM sleep-off neurons. Generalized atonia originates in dorsolateral portions of the pontine reticular formation and descend to the medulla and spinal cord to bring postural atonia. Muscle atonia characteristic of REM sleep produces both cataplexy and sleep paralysis. Disruptions induced experimentally of these neurons can cause REM sleep without atonia. Reports on narcolepsy following traumatic brain injury have been previously described in the literature.CASE PRESENTATION: We report a case of a 25 year old woman referred to Sleep Clinic with complaints of episodes of drifting off and suffocating while in bed for about 2 years, with visual hallucinations of a figure in the room or the surroundings, feeling paralyzed during these episodes, that occur approximately 3 to four times per week, sometimes occuring more than once per night. Sleep paralysis, nightmares were described. Excessive daytime sleepiness was observed, with propensity to naps that could last 3 to 4 hours and were refreshing. Epworth Sleepiness scale was 6. There was no family history of parasomnias. She denied snoring or sleep attacks. She noticed the symptoms described occurred two years ago after a car accident, when she suffered a concussion. She had reported a recent 15 Lbs weight gain. On Physical exam she had an airway Mallampati class II and was obese (BMI 32) without any neurological findings. Polysomnography results were as follows: Total sleep time: 494 min (efficiency 93%), Sleep latency: 13 min and REM latency: 5 min. Sleep disordered breathing was not observed. Multiple Sleep Latency Test results were: Mean sleep latency of 10 min with mean REM latency of 7.7 min and 3 SOREMPs.DISCUSSION: We describe a case of Narcolepsy without cataplexy presenting after a concussion following a car accident. Prior associations with multiple sclerosis, encephalitis and had trauma have been reported, but the temporal relationship between these and the onset of symptoms were not clearly established. Hypnagogic hallucinations, sleep paralysis and nightmares are often present in the general population and may not warrant additional testing.CONCLUSIONS: In our patient, her excessive daytime sleepiness and temporal relationship with the diagnosis of concussion were helpful elucidating her final diagnosis of Narcolepsy.1) Castriotta R, Murthy J. Sleep disorders in patients with traumatic brain injury: A Reveiw. CNS Drugs; 2011, 25175-852) Clavelou P, Tournilhac M, Vidal C, et al. Narcolepsy associated with arteriovenous malformation of the diencephalon. Sleep; 1995, 18:202-5DISCLOSURE: The following authors have nothing to disclose: Veronica Brito, Chrisoula Politis, Shalinee ChawlaNo Product/Research Disclosure InformationWinthrop University Hospital, Mineola, NY. Language: en