BackgroundPeople with epilepsy often experience daytime vigilance problems and fatigue. This may be related to disturbed sleep due to nocturnal seizures.AimTo compare subjective and objective... Show moreBackgroundPeople with epilepsy often experience daytime vigilance problems and fatigue. This may be related to disturbed sleep due to nocturnal seizures.AimTo compare subjective and objective markers of vigilance and circadian function in adults with epilepsy with nocturnal seizures to those with daytime seizures and healthy controls and to identify determinants of impaired daytime vigilance in epilepsy in an explorative study.MethodsWe included 30 adults with epilepsy (15 with daytime seizures and 15 with nocturnal seizures), and 15 healthy controls. All participants filled out the Epworth sleepiness scale (ESS), fatigue severity scale (FSS), Pittsburgh sleep quality index (PSQI) and the Munich chronotype questionnaire (MCTQ). Each participant performed two trials of the sustained attention to response task (SART) as a measure of vigilance, and had a post-illumination pupil response (PIPR) assessment as a marker for the circadian function.ResultsBoth epilepsy groups reported more fatigue on the FSS than healthy controls (p < .001) and had higher SART error scores (p = .026). The poorer FSS and SART scores were most prominent among those with nocturnal seizures. The ESS, PSQI, MCTQ and the primary PIPR outcome did not differ between groups. Having nocturnal seizures (p = .010) and using more antiseizure medications (p = .004) were related to increased SART error scores.ConclusionsNocturnal epilepsy is associated with poorer vigilance, indicating lower quality of wake time. We could not relate this to circadian dysfunction. Further studies should focus on vigilance problems in people with nocturnal epilepsy and explore interventions to improve the quality of wake time. Show less
Vael, V.E.C.; Bijlenga, D.; Schinkelshoek, M.S.; Sluiszen, N.N.J.J.M. van der; Remmerswaal, A.; Overeem, S.; ... ; Fronczek, R. 2023
Excessive daytime sleepiness is the core symptom of central disorders of hypersomnolence (CDH) and can directly impair driving performance. Sleepiness is reflected in relative alterations in... Show moreExcessive daytime sleepiness is the core symptom of central disorders of hypersomnolence (CDH) and can directly impair driving performance. Sleepiness is reflected in relative alterations in distal and proximal skin temperature. Therefore, we examined the predictive value of skin temperature on driving performance. Distal and proximal skin temperature and their gradient (DPG) were continuously measured in 44 participants with narcolepsy type 1, narcolepsy type 2 or idiopathic hypersomnia during a standardised 1-h driving test. Driving performance was defined as the standard deviation of lateral position (SDLP) per 5 km segment (equivalent to 3 min of driving). Distal and proximal skin temperature and DPG measurements were averaged over each segment and changes over segments were calculated. Mixed-effect model analyses showed a strong, quadratic association between proximal skin temperature and SDLP (p < 0.001) and a linear association between DPG and SDLP (p < 0.021). Proximal skin temperature changes over 3 to 15 min were predictive for SDLP. Moreover, SDLP increased over time (0.34 cm/segment, p < 0.001) and was higher in men than in women (3.50 cm, p = 0.012). We conclude that proximal skin temperature is a promising predictor for real-time assessment of driving performance in people with CDH. Show less
Hoeven, A.E. van der; Bijlenga, D.; Bouhuijs, P.; Schie, M.K.M. van; Lammers, G.J.; Fronczek, R. 2023
Objective/backgroundEvaluation of hypersomnolence disorders ideally includes an assessment of vigilance using the short Sustained Attention to Response Task (SART). We evaluated whether this task... Show moreObjective/backgroundEvaluation of hypersomnolence disorders ideally includes an assessment of vigilance using the short Sustained Attention to Response Task (SART). We evaluated whether this task can differentiate between hypersomnolence disorders, whether it correlates with subjective and objective sleepiness, whether it is affected by the time of day, and symptoms of anxiety and depression.Patients/methodsWe analyzed diagnostic data of 306 individuals with hypersomnolence complaints diagnosed with narcolepsy type 1 (n=100), narcolepsy type 2 (n=20), idiopathic hypersomnia (n=49), obstructive sleep apnea (n=27) and other causes or without explanatory diagnosis (n=110). We included the Multiple Sleep Latency Test (MSLT), polysomnography, Epworth Sleepiness Scale (ESS), Hospital Anxiety and Depression Scale and SART, which were administered five times during the day (outcomes: reaction time, total, commission and omission errors).ResultsThe SART outcomes did not differ between groups when adjusted for relevant covariates. Higher ESS scores were associated with longer reaction times and more commission errors (p<.01). The main outcome, total errors, did not differ between times of the day. Reaction times and omission errors were impacted (p<.05).ConclusionsThe SART quantifies disturbed vigilance, an important dimension of disorders of hypersomnolence. Results do not suggest that depressive symptoms influence SART outcomes. A practice session is advised. Testing time should be taken into account when interpreting results. We conclude that the SART does not differentiate between central disorders of hypersomnolence. It may be a helpful addition to the standard diagnostic workup and monitoring of these disorders. Show less
Study Objectives To review the Maintenance of Wakefulness Test (MWT) as assessment of daytime sleepiness in the evaluation of treatment effects and driving fitness in central disorders of... Show moreStudy Objectives To review the Maintenance of Wakefulness Test (MWT) as assessment of daytime sleepiness in the evaluation of treatment effects and driving fitness in central disorders of hypersomnolence (CDH). Methods We performed a scoping review of studies using the MWT in patients with CDH (i.e. narcolepsy types 1 and 2, and idiopathic hypersomnia). N = 20 articles were included, comprising 683 patients and 129 controls. MWT effect sizes were compared to the Clinical Global Impression (GCI) scale and the Epworth Sleepiness Scale (ESS). MWT sleep latency was correlated to objective driving performances. The role of motivation was evaluated by comparing MWTs of treatment studies (low motivation) to driving fitness studies (high motivation to stay awake). Healthy controls were compared to norm values. Results MWT and CGI were both impacted by the same treatment; however, the MWT has higher effect sizes and was more sensitive to measure these effects. The MWT correlated fairly to moderately (rho = -0.26 to -0.56; p <= .05) to objective driving performance. Motivation played a major role on MWT sleep latencies (d = 0.76 to 1.43; p <= .001). Current norm values may not be valid, as sleep latency may be impacted by age. Conclusions The MWTs applicability to measure treatment effects in CDH was confirmed, but age-adjusted norm values are needed. For a more complete evaluation of EDS it should be combined with subjective measures. Its reliability for driving fitness evaluation is insufficient, and motivation plays a major role. To predict or monitor driving performance in CDH, valid and easy methods should be developed. Show less
Hoeven, A.E. van der; Waaij, K. van; Bijlenga, D.; Roelandse, F.W.C.; Overeem, S.; Bakker, J.A.; ... ; Lammers, G.J. 2022
Study Objectives The most sensitive and specific investigative method for the diagnosis of narcolepsy type 1 (NT1) is the determination of hypocretin-1 (orexin-A) deficiency (<= 110 pg/mL) in... Show moreStudy Objectives The most sensitive and specific investigative method for the diagnosis of narcolepsy type 1 (NT1) is the determination of hypocretin-1 (orexin-A) deficiency (<= 110 pg/mL) in cerebrospinal fluid using a radioimmunoassay (RIA). We aimed to assess the reliability of the Phoenix Pharmaceuticals hypocretin-1 RIA, by determining the lower limit of quantification (LLOQ), the variability around the cutoff of 110 pg/mL, and the inter- and intra-assay variability. Methods: Raw data of 80 consecutive hypocretin-1 RIAs were used to estimate the intra- and inter-assay coefficient of variation (CV). The LLOQ was established and defined as the lowest converted concentration with a CV Results: The mean intra-assay CV was 4.7%, while the unconverted inter-assay CV was 28.3% (18.5% excluding 2 outliers) and 7.5% when converted to international values. The LLOQ was determined as 27.9 pg/mL. The intra-assay CV of RIAs with lower specific radioactive activity showed a median of 5.6% (n = 41, range 1.6%-17.0%), which was significantly higher than in RIAs with higher specific activity (n = 36; median 3.2%, range 0.4%-11.6%, p = .013). The CV around the 110 pg/mL cutoff was <7%. Conclusions: Hypocretin-1 RIAs should always be harmonized using standard reference material. The specific activity of an RIA has a significant impact on its reliability, because of the decay of I-125 radioactivity. Values around the hypocretin-1 cut-off can reliably be measured. Hypocretin-1 concentrations below 28 pg/mL should be reported as "undetectable" when measured with the Phoenix Pharmaceuticals RIA. Show less
Study Objectives: The diagnosis of narcolepsy type 1 (NT1) is based upon the presence of cataplexy and/or a cerebrospinal fluid (CSF) hypocretin-1/orexin-A level <= 110 pg/mL. We determined the... Show moreStudy Objectives: The diagnosis of narcolepsy type 1 (NT1) is based upon the presence of cataplexy and/or a cerebrospinal fluid (CSF) hypocretin-1/orexin-A level <= 110 pg/mL. We determined the clinical and diagnostic characteristics of patients with intermediate hypocretin-1 levels (111-200 pg/mL) and the diagnostic value of cataplexy characteristics in individuals with central disorders of hypersomnolence. Methods: Retrospective cross-sectional study of 355 people with known CSF hypocretin-1 levels who visited specialized Sleep-Wake Centers in the Netherlands. For n = 271, we had full data on cataplexy type ("typical" or "atypical" cataplexy). Results: Compared to those with normal hypocretin-1 levels (>200 pg/mL), a higher percentage of individuals with intermediate hypocretin-1 levels had typical cataplexy (75% or 12/16 vs 9% or 8/88, p < .05), and/or met the diagnostic polysomnographic (PSG) and Multiple Sleep Latency Test (MSLT) criteria for narcolepsy (50 vs 6%, p < .001). Of those with typical cataplexy, 88% had low, 7% intermediate, and 5% normal hypocretin-1 levels (p < .001). Atypical cataplexy was also associated with hypocretin deficiency but to a lesser extent. A hypocretin-1 cutoff of 150 pg/mL best predicted the presence of typical cataplexy and/or positive PSG and MSLT findings. Conclusion: Individuals with intermediate hypocretin-1 levels or typical cataplexy more often have outcomes fitting the PSG and MSLT criteria for narcolepsy than those with normal levels or atypical cataplexy. In addition, typical cataplexy has a much stronger association with hypocretin-1 deficiency than atypical cataplexy. We suggest increasing the NT1 diagnostic hypocretin-1 cutoff and adding the presence of clearly defined typical cataplexy to the diagnostic criteria of NT1. Show less
Study ObjectivesThe diagnosis of narcolepsy type 1 (NT1) is based upon the presence of cataplexy and/or a cerebrospinal fluid (CSF) hypocretin-1/orexin-A level ≤ 110 pg/mL. We determined the... Show moreStudy ObjectivesThe diagnosis of narcolepsy type 1 (NT1) is based upon the presence of cataplexy and/or a cerebrospinal fluid (CSF) hypocretin-1/orexin-A level ≤ 110 pg/mL. We determined the clinical and diagnostic characteristics of patients with intermediate hypocretin-1 levels (111–200 pg/mL) and the diagnostic value of cataplexy characteristics in individuals with central disorders of hypersomnolence.MethodsRetrospective cross-sectional study of 355 people with known CSF hypocretin-1 levels who visited specialized Sleep-Wake Centers in the Netherlands. For n = 271, we had full data on cataplexy type (“typical” or “atypical” cataplexy).ResultsCompared to those with normal hypocretin-1 levels (>200 pg/mL), a higher percentage of individuals with intermediate hypocretin-1 levels had typical cataplexy (75% or 12/16 vs 9% or 8/88, p < .05), and/or met the diagnostic polysomnographic (PSG) and Multiple Sleep Latency Test (MSLT) criteria for narcolepsy (50 vs 6%, p < .001). Of those with typical cataplexy, 88% had low, 7% intermediate, and 5% normal hypocretin-1 levels (p < .001). Atypical cataplexy was also associated with hypocretin deficiency but to a lesser extent. A hypocretin-1 cutoff of 150 pg/mL best predicted the presence of typical cataplexy and/or positive PSG and MSLT findings.ConclusionIndividuals with intermediate hypocretin-1 levels or typical cataplexy more often have outcomes fitting the PSG and MSLT criteria for narcolepsy than those with normal levels or atypical cataplexy. In addition, typical cataplexy has a much stronger association with hypocretin-1 deficiency than atypical cataplexy. We suggest increasing the NT1 diagnostic hypocretin-1 cutoff and adding the presence of clearly defined typical cataplexy to the diagnostic criteria of NT1. Show less
Patients with narcolepsy or idiopathic hypersomnia (IH) are at increased risk of driving accidents. Both excessive daytime sleepiness, i.e. unwanted sleep episodes during the day, and disturbed... Show morePatients with narcolepsy or idiopathic hypersomnia (IH) are at increased risk of driving accidents. Both excessive daytime sleepiness, i.e. unwanted sleep episodes during the day, and disturbed vigilance are core features of these disorders. We tested on-the-road driving performance of patients with narcolepsy or IH coming in for a routine driving fitness evaluation and examined: (1) correlations between driving performance and the Maintenance of Wakefulness Test (MWT), Sustained Attention to Response Task (SART) and Psychomotor Vigilance Test (PVT) as objective tests; (2) the predictive power of the MWT and SART for increased risk of impaired driving; (3) the best set of objective predictors for increased risk of impaired driving. Participants were 44 patients (aged 18-75 years) with narcolepsy type 1 (NT1), type 2 (NT2) or IH. They completed the MWT, SART, PVT, a subjective sleepiness questionnaire, and a standardised on-the-road driving test. The standard deviation of the lateral position (SDLP) was used as outcome measure of driving performance. The MWT had low correlation with the SDLP (rho = -0.41 to -0.49, p < 0.01). The SART and PVT had low correlations with SDLP (rho = 0.30 and rho = 0.39, respectively, both p < 0.05). The predictive power of MWT for an increased risk of impaired driving was significant, but low (area under the curve = 0.273, p = 0.012), and non-significant for SART. We conclude that in our present group, none of the tests had adequate ability to predict impaired driving, questioning their use for clinical driving fitness evaluation in narcolepsy and IH. Real-time monitoring of sleepiness while driving seems more promising in these patients. Show less
Vogel, S.W.N.; Bijlenga, D.; Tanke, M.; Bron, T.I.; Heijden, K.B. van der; Swaab, H.; ... ; Kooij, J.J.S. 2015
Objective To compare the effect of induction of labour with a policy of expectant monitoring for intrauterine growth restriction near term. Design Multicentre randomised equivalence trial (the... Show moreObjective To compare the effect of induction of labour with a policy of expectant monitoring for intrauterine growth restriction near term. Design Multicentre randomised equivalence trial (the Disproportionate Intrauterine Growth Intervention Trial At Term (DIGITAT)). Setting Eight academic and 44 non-academic hospitals in the Netherlands between November 2004 and November 2008. Participants Pregnant women who had a singleton pregnancy beyond 36+0 weeks' gestation with suspected intrauterine growth restriction. Interventions Induction of labour or expectant monitoring. Main outcome measures The primary outcome was a composite measure of adverse neonatal outcome, defined as death before hospital discharge, five minute Apgar score of less than 7, umbilical artery pH of less than 7.05, or admission to the intensive care unit. Operative delivery (vaginal instrumental delivery or caesarean section) was a secondary outcome. Analysis was by intention to treat, with confidence intervals calculated for the differences in percentages or means. Results 321 pregnant women were randomly allocated to induction and 329 to expectant monitoring. Induction group infants were delivered 10 days earlier (mean difference -9.9 days, 95% CI -11.3 to -8.6) and weighed 130 g less (mean difference -130 g, 95% CI -188 g to -71 g) than babies in the expectant monitoring group. A total of 17 (5.3%) infants in the induction group experienced the composite adverse neonatal outcome, compared with 20 (61%) in the expectant monitoring group (difference -0.8%, 95% CI -4.3% to 3.2%). Caesarean sections were performed on 45 (14.0%) mothers in the induction group and 45 (13.7%) in the expectant monitoring group (difference 0.3%, 95% CI -5.0% to 5.6%). Conclusions In women with suspected intrauterine growth restriction at term, we found no important differences in adverse outcomes between induction of labour and expectant monitoring. Patients who are keen on non-intervention can safely choose expectant management with intensive maternal and fetal monitoring; however, it is rational to choose induction to prevent possible neonatal morbidity and stillbirth. Show less
