P10 Normative MSLT Values for Hypersomnia Presentations

Introduction Narcolepsy is typically diagnosed by symptoms and an abnormal multiple sleep latency test (MSLT). However, many factors can affect the results of the MSLT, leading to an overdiagnosis of narcolepsy. Report of case(s) A 37-year-old female was referred with prior diagnoses of narcolepsy, depression, post-traumatic stress disorder, polysubstance abuse, obstructive sleep apnea (OSA), and hypertension. The patient obtained the diagnosis of narcolepsy by polysomnography/MSLT through another facility and was prescribed amphetamine/dextroamphetamine. The overnight polysomnogram demonstrated: total sleep time 285 minutes, rapid-eye movement (REM) latency 223 minutes, overall apnea-hypopnea index (AHI) 6/h, and REM AHI 45/h. The next day MSLT demonstrated a mean sleep latency of 7 minutes and 2 sleep-onset REM periods on the second and fourth naps. A urine drug screen (UDS) was not obtained. She reported 4-6 hours of sleep/day at the time of her MSLT. She denied cataplexy, sleep paralysis, or sleep-related hallucinations. Conclusion This case is one of many seen at our tertiary referral center of patients presenting with a diagnosis of narcolepsy by MSLT, but the MSLT was performed in invalid conditions. Many medications, substances, insufficient sleep, inappropriate timing of testing, untreated OSA, and other medical conditions all have the potential to lead to an abnormal MSLT that would appear consistent with narcolepsy, but often these factors are not considered. Insufficient sleep at home or on the preceding polysomnogram can lead to an abnormal MSLT. Though our patient had a history of polysubstance abuse, a UDS was not obtained. The American Academy of Sleep Medicine enjoins a polysomnogram for a duration of a 7-hour minimum (with 6 hours of sleep) prior to conducting an MSLT. Our patient only slept for 4.75 hours in the overnight polysomnogram. Her polysomnogram also showed OSA. A combination of these factors likely contributed to the patient’s daytime sleepiness. Her insufficient sleep, OSA, and use of sedating medications/substances should have been addressed first before performing an MSLT. We strongly encourage providers to ensure the MSLT is done in valid conditions to prevent the misdiagnosis of narcolepsy and initiation of unnecessary treatment. Support (if any)

IntroductionThe gold standard investigation for central disorders of hypersomnolence in children is the Multiple Sleep Latency Test (MSLT). MSLT diagnostic cut-offs are extrapolated from adult data. Currently there are no guidelines available regards the utility and timing of repeating paediatric MSLTs. MethodsRetrospective review of children with ≥2MSLTs at our tertiary centre between 2005–2022. Narcolepsy defined as mean sleep latency (MSL) <8min with ≥2 sleep onset REM (SOREM); idiopathic hypersomnolence (IH) defined as MSL <8min with <2 SOREM. MSLTs not meeting these criteria were labelled non-diagnostic.Progress19 children (9F) with initial non-diagnostic MSLT underwent repeat MSLT with 5 proceeding to a 3rd MSLT following 2 non-diagnostic MSLTs. Repeat MSLT resulted in diagnosis in 6/19 (32%) (3 narcolepsy, 3 IH); whereas only 1/5 3rd repeat MSLT was diagnostic (IH). Median age at initial MSLT was 7.5y (range 3.4-17.8y), with repeat after 2.9y (range 0.9-8.2y), and 3rd after 2.1 years (range 1.2-4.2y). Mean change in MSL on repeat testing was -2min (range -15.5min to +4.9min, p=0.18). MSL reduced to <10 minutes in one child, allowing access to PBS subsidised treatment. Of the 7 diagnostic repeat MSLTs, 2 had ≥2 SOREM and reduced MSL, 1 had reduced MSL (with 3 SOREM on initial and subsequent test), 4 had reduced MSL without SOREM.OutcomeA third of repeat MSLTs became diagnostic, suggesting repeat MSLT in childhood should be considered if clinical suspicion persists. Further work needs to address the repeat interval between MSLTs and current diagnostic cut-points in the paediatric population.

The differentiation of narcolepsy without cataplexy from idiopathic hypersomnia is based on the number of sleep-onset rapid eye movement periods (SOREMPs) observed by multiple sleep latency test (MSLT) and nocturnal polysomnography. The main aim of this study was to investigate the utility of SOREMP in differential diagnosis of central hypersomnias. The authors retrospectively evaluated consecutive 101 patients with a normal polysomnography other than the presence of SOREMP and/or REM without atonia and a latency of ≤8 minutes in MSLT. The authors classified patients as follows: 52 patients had at least 2 SOREMPs (narcolepsy group), 23 had no SOREMPs (idiopathic hypersomnia group), and 26 patients had only 1 SOREMP (intermediate group). In polysomnographic recordings, both mean sleep latency and REM latency were significantly shorter in the narcolepsy (P = 0.012, P < 0.001, respectively) and intermediate groups (P = 0.005 and P = 0.035, respectively) compared with the idiopathic hypersomnia group. In MSLT recordings, sleep latency was 2.7 ± 2.2 minutes in the narcolepsy group, 3.6 ± 1.4 minutes in the intermediate group, and 5.2 ± 2.7 minutes in the idiopathic hypersomnia group (P < 0.001). The mean REM latency and sleep stages SOREMPs arised from were similar between the narcolepsy and intermediate groups. To date, SOREMPs in MSLT and polysomnography remain the sole electrodiagnostic feature that discriminates narcolepsy without cataplexy from idiopathic hypersomnia. Different parameters or combined criteria are being increasingly investigated to increase the sensitivity and specificity of MSLT. The findings showed an altered instability of REM sleep not only in patients with 2 or more SOREMPs in MSLT but also in patients with one SOREMP.

Introduction The correlation between the Epworth Sleepiness Scale (ESS) and mean sleep latency (MSL) on a Multiple Sleep Latency Test (MSLT) has been the subject of extensive research in sleep medicine. Higher ESS scores are often associated with shorter sleep latencies on MSLT. However, this finding has not been consistent in all clinical contexts. We performed a cross-sectional analysis of MSLT studies, testing this correlation while taking into consideration different final sleep diagnoses. Methods MSLTs performed at Memorial Hermann Sleep Disorders Center at Texas Medical Center between November 2020 and November 2024 were reviewed. Exclusion criteria included insufficient polysomnographic data quality or unavailable final report. Demographic and polysomnographic data were collected to include the MSLT findings and documentation of the final diagnosis. A correlation between the ESS scores and the MSLs was made with linear regression analysis (using a 95% confidence interval), first as an entire group followed by only those studies that met the criteria for narcolepsy (type 1 or 2). Results 33 studies were identified, and 22 studies were included for analysis. The average age was 25.7 years (SD +/- 11.4), comprising 23% males and 77% females. The average ESS score was 15.4 (SD +/- 4.9) and the average sleep time on the overnight PSG was 422 minutes (SD +/- 61.4). The prevalence of narcolepsy was 23%. The R2 value when comparing the ESS and MSL for the entire group was only 2%. When performing the same analysis on the studies that were diagnostic of narcolepsy, the R2 was 82% (p-value 0.03) demonstrating a strong correlation. The average ESS in this subgroup was 17.2 (SD +/- 4.9). Conclusion When patients are referred for an MSLT, their ESS score is typically known. We found that patients diagnosed with narcolepsy had a higher correlation between their ESS score and the mean sleep latency on the MSLT compared to those who did not get a narcolepsy diagnosis. Thus, the ESS score is a strong predictor of a positive diagnosis of narcolepsy on an MSLT. Support (if any) None.

IntroductionSleepiness is a subjective symptom, often reported by patients with sleep disorders. We investigated subjective measures of sleepiness, as measured by the Epworth Sleepiness Scale (ESS), and correlated this to...

Teleworking during a pandemic: perspective of an idiopathic hypersomnia patient.

Excessive daytime sleepiness (EDS) has different correlates in non-rapid eye movement (NREM) [idiopathic hypersomnia (IH) without long sleep time] and REM sleep [narcolepsy without cataplexy (NwoC) and narcolepsy with cataplexy (NC)]-related hypersomnias of central origin. We analysed sleep onset characteristics at the multiple sleep latency test (MSLT) applying simultaneously two sleep onset criteria in 44 NC, seven NwoC and 16 IH consecutive patients referred for subjective EDS complaint. Sleep latency (SL) at MSLT was assessed both as the time elapsed to the occurrence of a single epoch of sleep Stage 1 NREM (SL) and of unequivocal sleep [three sleep Stage 1 NREM epochs or any other sleep stage epoch, sustained SL (SusSL)]. Idiopathic hypersomnia patients showed significantly (P<0.0001) longer SusSL than SL (7.7±2.5 versus 5.6±1.3 min, respectively) compared to NwoC (5.8±2.5 versus 5.3±2.2 min) and NC patients (4.1±3 versus 3.9±3 min). A mean difference threshold between SusSL and SL ≥27 s reached a diagnostic value to discriminate IH versus NC and NwoC sufferers (sensitivity 88%; specificity 82%). Moreover, NC patients showed better subjective sleepiness perception than NwoC and IH cases in the comparison between naps with or without sleep occurrence. Simultaneous application of the two widely used sleep onset criteria differentiates IH further from NC and NwoC patients: IH fluctuate through a wake-Stage 1 NREM sleep state before the onset of sustained sleep, while NC and NwoC shift abruptly into a sustained sleep. The combination of SusSL and SL determination at MSLT should be tested as an additional objective differential criterion for EDS disorders.

BackgroundExcessive daytime sleepiness is a frequent complaint in Parkinson’s disease (PD); however the frequency and risk factors for objective sleepiness remain mostly unknown. We investigated both the frequency and determinants of self-reported and objective daytime sleepiness in patients with Parkinson’s disease (PD) using a wide range of potential predictors.MethodsOne hundred and thirty four consecutive patients with PD, without selection bias for sleep complaint, underwent a semi-structured clinical interview and a one night polysomnography followed by a multiple sleep latency test (MSLT). Demographic characteristics, medical history, PD course and severity, daytime sleepiness, depressive and insomnia symptoms, treatment intake, pain, restless legs syndrome, REM sleep behaviour disorder, and nighttime sleep measures were collected. Self-reported daytime sleepiness was defined by an Epworth Sleepiness Scale (ESS) score above 10. A mean sleep latency on MSLT below 8 minutes defined objective daytime sleepiness.ResultsOf 134 patients with PD, 46.3% had subjective and only 13.4% had objective sleepiness with a weak negative correlation between ESS and MSLT latency. A high body mass index (BMI) was associated with both ESS and MSLT, a pain complaint with ESS, and a higher apnea/hypopnea index with MSLT. However, no associations were found between both objective and subjective sleepiness, and measures of motor disability, disease onset, medication (type and dose), depression, insomnia, restless legs syndrome, REM sleep behaviour disorder and nighttime sleep evaluation.ConclusionWe found a high frequency of self-reported EDS in PD, a finding which is however not confirmed by the gold standard neurophysiological evaluation. Current treatment options for EDS in PD are very limited; it thus remains to be determined whether decreasing pain and BMI in association with the treatment of sleep apnea syndrome would decrease significantly daytime sleepiness in PD.

The multiple sleep latency test (MSLT) is the standard method for the objective measurement of excessive daytime sleepiness. It is well established that preceding factors may influence the MSLT result. Aim of this study was to evaluate the potential influence of a post-test factor on the MSLT outcome. For this retrospective study we reviewed polysomnography (PSG) reports conducted between 2012 and 2013. PSG reports including MSLT with at least four runs were included. Patients were stratified into (1) those discharged immediately after the MSLT or (2) those discharged on the following day. For further analysis, we categorized the patients into three subgroups according to mean MSLT sleep latency: < 5, 5-9.9, and 10-19.9 minutes, corresponding to a pathological, borderline, and normal MSLT result. A total of 2,749 PSG records were reviewed; 262 included MSLT and 241 met inclusion criteria for the study. Of those, 152 patients were discharged immediately after the last MSLT run, 89 on the following day. MSLT mean sleep latency, and sleep latency of the last run only, did not differ between both groups (p = 0.070 and p = 0.065). In the subgroup of patients with pathological MSLT, there was a trend towards prolonged sleep latency in the last run in patients discharged immediately after the test (p = 0.055). Our findings suggest that the MSLT post-test factor of discharge timing has no major impact on the MSLT outcome.

Hypersomnia may be classified as primary or secondary, with secondary hypersomnia arising from a variety of underlying causes. Thus, according to ICSD3-TR classification, the diagnosis of idiopathic hypersomnia (IH) is established based on (1) excessive daytime sleepiness (EDS); (2) electrophysiological findings including either a mean sleep latency of less than 8 min on the Multiple Sleep Latency Test (MSLT) or increased total sleep (≥11 h) on 24 h polysomnography; and (3) systematic elimination of other potential etiologies, including sleep deprivation, substances, and medical, psychiatric (notably mood disorders), or sleep disorders. Nevertheless, the clinical heterogeneity observed in IH fuels an ongoing debate, reflecting the limited understanding of its underlying pathophysiological mechanisms. This report describes the case of a patient presenting with a clinical and polysomnographic phenotype of IH (MSLT < 8 min). A comprehensive psychopathological evaluation was performed to explore the possibility of secondary hypersomnia, which revealed features consistent with complex post-traumatic stress disorder (c-PTSD). Psychotherapy focused on c-PTSD was administered with positive and objective results in hypersomnolence/EDS. This clinical improvement suggests a potential relationship between psychological trauma and hypersomnia, a connection that is rarely described in the literature and warrants further investigation. This case highlights the need for a comprehensive assessment of secondary factors, particularly complex trauma, even in the presence of a clinical and polysomnographic phenotype consistent with IH.

Excessive daytime sleepiness in adults with brain injuries

Caffeine challenge in insomniac patients after total sleep deprivation

According to the 2005 International Classification of Sleep Disorders (ICSD-2), narcolepsy and idiopathic hypersomnia are considered hypersomnias of central origin (American Academy of Sleep Medicine. International Classification of Sleep Disorders. Diagnostic and coding manual. 2nd ed. Westchester: American Academy of Sleep Medicine; 2005). In this chapter we will review the treatment of these two conditions. The pathophysiology of idiopathic hypersomnia remains unclear. Large systematic studies are lacking due to the rare prevalence of idiopathic hypersomnia. Treatment is mostly focused on excessive daytime sleepiness (EDS). We will discuss presently available and emerging treatment options for narcolepsy. Symptomatic treatment options for narcolepsy are used for EDS in patients with idiopathic hypersomnia.

Background and Objective Several studies have raised questions about determining the diagnosis of the narcolepsy using multiple sleep latency test (MSLT). In this study, we investigated the diagnostic change in narcolepsy type 1 (NT1) and narcolepsy type 2 (NT2) using MSLT with long-term interval.Methods In this retrospective study, the demographic characteristics, polysomnography (PSG), and MSLT parameters were compared at the baseline between the NT1 and NT 2 patients. Then, MSLT re-tests were conducted with a mean follow-up of 8.48 years in patients with NT 1 and 7.05 years with NT 2.Results Seventy-four patients (58 with NT1 and 16 with NT2) were investigated in this study. At the baseline, demographic data showed a larger body mass index value, more sleep paralysis, and hypnogogic hallucination in NT 1 compared to NT 2. Also, at baseline MSLT, shorter mean sleep latency and higher number of sleep onset rapid eye movement periods (SOREMPs) were observed in the NT 1 than those of the NT 2. On follow-up MSLT, 6.9% (n = 4) patients with NT1 and 50% (n = 8) patients with NT2 did not satisfy the previous diagnosis. Furthermore, in all the groups who had the change in repeated-MSLT, the groups with less than 2 SOREMPs observed to be accompanied by negative MSL at follow-up.Conclusions The result of MSLT was observed not to be stable in the diagnosis of NT 2 at the study. Therefore, it is recommended to repeat MSLT at regular intervals and do a prospective multi-site survey for the accurate confirmation of a diagnosis of central hypersomnia.

Background/Aims: Excessive daytime sleepiness (EDS) is frequent in patients with Parkinson’s disease (PD). Occasionally, EDS in PD exhibits narcolepsy-like features. We aimed to assess characteristics and determinants of EDS in consecutive patients with PD. Methods: Thirty consecutive patients with PD underwent a detailed clinical examination. EDS was assessed using the Epworth Sleepiness Scale (ESS) and Multiple Sleep Latency Test (MSLT). Sleep was assessed using video-polysomnography. Cerebrospinal fluid (CSF) hypocretin-1 levels were obtained in 3 patients. Results: ESS was >10 in 17 patients (57%). Mean sleep latency (MSL) on MSLT was <5 min in 11 patients (37%). There was a significant negative correlation between ESS and MSL. None of the 11 patients with MSL <5 min showed a sleep onset REM (SOREM) episode. Patients with EDS had higher dopamine agonists/levodopa equivalent doses, higher apnea/hypopnea index and exhibited wearing-off symptoms more often. Hypocretin-1 was normal in 3 patients tested. Conclusion: EDS, which can sometimes be severe, is common in PD patients even in the absence of SOREM and detectable CSF-hypocretin deficiency. In PD, EDS is a multifaceted phenomenon, the determinants of which include severity of PD, wearing-off symptoms, dosage of antiparkinsonian drugs and sleep-disordered breathing.