Severe obstructive sleep apnea in children with syndromic craniosynostosis: analysis of pulse transit time.

STUDY OBJECTIVES: We examined the association between pulse transit time (PTT) and obstructive sleep apnea (OSA) in children with syndromic craniosynostosis (SCS), where OSA is a common problem and may cause cardiorespiratory disturbance. METHODS: Retrospective study of children (age <18 years) with SCS and moderate-to-severe OSA (i.e., obstructive apnea-hypopnea index [oAHI] ≥ 5), or no OSA (oAHI < 1) who underwent overnight polysomnography (PSG). Children without SCS and normal PSG were included as controls. Reference intervals (RIs) for PTT were computed by non-parametric bootstrap analysis. Based on RIs of controls, the sensitivity and specificity of PTT to detect OSA were determined. In a linear mixed-model the explanatory variables assessed were sex, age, sleep stage, and time after obstructive events. RESULTS: In all 68 included children (19 SCS with OSA, 30 SCS without OSA, 19 controls), obstructive events occurred throughout all sleep stages, most prominently during rapid eye movement sleep (REM) and non-REM sleep stages N1 and N2, with evident PTT changes. Greatest reductions were observed 4 - 8 s after an event (p < 0.05). In SCS with OSA, PTT RIs were lower during all sleep stages compared to SCS without OSA. The highest sensitivity was observed during N1 (55.5%), and the highest specificity during REM (76.5%). Lowest PTT values were identified during N1. CONCLUSIONS: Obstructive events occur throughout all sleep stages with transient reductions in PTT. However, PTT as a variable for OSA detection is limited by its sensitivity and specificity.

An electroencephalography-based sleep index and supervised machine learning as a suitable tool for automated sleep classification in children.

STUDY OBJECTIVES: Although sleep is frequently disrupted in the pediatric intensive care unit, it is currently not possible to perform real-time sleep monitoring at the bedside. In this study, spectral band powers of electroencephalography data are used to derive a simple index for sleep classification. METHODS: Retrospective study at Erasmus MC Sophia Children's Hospital, using hospital-based polysomnography recordings obtained in non-critically ill children between 2017 and 2021. Six age categories were defined: 6-12 months, 1-3 years, 3-5 years, 5-9 years, 9-13 years, and 13-18 years. Candidate index measures were derived by calculating spectral band powers in different frequent frequency bands of smoothed electroencephalography. With the best performing index, sleep classification models were developed for two, three, and four states via decision tree and five-fold nested cross-validation. Model performance was assessed across age categories and electroencephalography channels. RESULTS: In total 90 patients with polysomnography were included, with a mean (standard deviation) recording length of 10.3 (1.1) hours. The best performance was obtained with the gamma to delta spectral power ratio of the F4-A1 and F3-A1 channels with smoothing. Balanced accuracy was 0.88, 0.74, and 0.57 for two-, three-, and four-state classification. Across age categories, balanced accuracy ranged between 0.83 and 0.92 and 0.72 and 0.77 for two- and three-state classification, respectively. CONCLUSIONS: We propose an interpretable and generalizable sleep index derived from single-channel electroencephalography for automated sleep monitoring at the bedside in non-critically ill children ages 6 months to 18 years, with good performance for two- and three-state classification. CITATION: van Twist E, Hiemstra FW, Cramer ABG, et al. An electroencephalography-based sleep index and supervised machine learning as a suitable tool for automated sleep classification in children. J Clin Sleep Med. 2024;20(3):389-397.

Accelerometer-based quantitative analysis of axial nocturnal movements differentiates patients with Parkinson's disease, but not high-risk individuals, from controls.

INTRODUCTION: There is a need for prodromal markers to diagnose Parkinson's disease (PD) as early as possible. Knowing that most patients with overt PD have abnormal nocturnal movement patterns, we hypothesised that such changes might occur already in non-PD individuals with a potentially high risk for future development of the disease. METHODS: Eleven patients with early PD (Hoehn & Yahr stage ≤2.5), 13 healthy controls and 33 subjects with a high risk of developing PD (HR-PD) were investigated. HR-PD was defined by the occurrence of hyperechogenicity of the substantia nigra in combination with prodromal markers (eg, slight motor signs, olfactory dysfunction). A triaxial accelerometer was used to quantify nocturnal movements during two nights per study participant. Outcome measurements included mean acceleration, and qualitative axial movement parameters, such as duration and speed. RESULTS: Mean acceleration of nocturnal movements was lower in patients with PD compared to controls. Frequency and speed of axial movements did not differ between patients with PD and controls, but mean size and duration were lower in PD. The HR-PD group did not significantly differ from the control group in any of the parameters analysed. CONCLUSIONS: Compared with controls, patients with PD had an overall decreased mean acceleration, as well as smaller and shorter nocturnal axial movements. These changes did not occur in our potential HR-PD individuals, suggesting that relevant axial movement alterations during sleep have either not developed or cannot be detected by the means applied in this at-risk cohort.

Actigraphy as a diagnostic aid for REM sleep behavior disorder in Parkinson's disease.

BACKGROUND: Rapid eye movement (REM) sleep behavior disorder (RBD) is a common parasomnia in Parkinson's disease (PD) patients. The current International Classification of Sleep Disorders (ICSD-II) requires a clinical interview combined with video polysomnography (video-PSG) to diagnose. The latter is time consuming and expensive and not always feasible in clinical practice. Here we studied the use of actigraphy as a diagnostic tool for RBD in PD patients. METHODS: We studied 45 consecutive PD patients (66.7% men) with and without complaints of RBD. All patients underwent one night of video-PSG and eight consecutive nights of actigraphy. Based on previous studies, the main outcome measure was the total number of bouts classified as "wake", compared between patients with (PD + RBD) and without RBD (PD- RBD). RESULTS: 23 (51.1%) patients had RBD according to the ICSD-II criteria. The total number of wake bouts was significantly higher in RBD patients (PD + RBD 73.2 ± 40.2 vs. PD-RBD 48.4 ± 23.3, p = .016). A cut off of 95 wake bouts per night resulted in a specificity of 95.5%, a sensitivity of 20.1% and a positive predictive value of 85.7%. Seven patients were suspected of RBD based on the interview alone, but not confirmed on PSG; six of whom scored below 95 wake bouts per night on actigraphy. CONCLUSION: PD patients with RBD showed a significantly higher number of bouts scored as "wake" using actigraphy, compared to patients without RBD. In clinical practice, actigraphy has a high specificity, but low sensitivity in the diagnosis of RBD. The combination of actigraphy and previously reported RBD questionnaires may be a promising method to diagnose RBD in patients with PD.

Restless legs syndrome in Parkinson's disease.

The Restless legs syndrome (RLS) and Parkinson's disease (PD) are two disorders that can co-exist, whether or not they share a common pathophysiology. If, and to what extent RLS and PD share the same pathophysiology, is still under debate. Sleep disturbances are prevalent in PD, and as PD progresses, nocturnal disturbances become even more evident, in association not only with motor symptoms but also with non-motor symptoms. Alertness to, and recognition of, RLS in PD patients with sleep disorders could improve customized treatment and quality of life of these patients. In this article the prevalence of RLS in PD, the clinical profile of RLS in PD, the PD profile of patients with RLS, RLS mimics specifically related to PD and impact of RLS in PD will be reviewed.

Subjectively impaired bed mobility in Parkinson disease affects sleep efficiency.

BACKGROUND: Impaired bed mobility (IBM) may be an important reason for the high prevalence of sleep insomnia in Parkinson disease (PD). Here we assessed the influence of subjectively IBM on both subjective and objective sleep parameters in insomnia PD patients with (PD+IBM) and without (PD-IBM) concerns of IBM and controls with primary insomnia. METHODS: We included 44 PD patients with sleep initiation or maintenance concerns and 44 control subjects with primary insomnia. Sleep questionnaires, polysomnographic sleep parameters, activity data, and the number of body position changes were compared between PD patients and controls as well as within the PD group between PD+IBM vs PD-IBM subjects. RESULTS: There were 54.5% of PD subjects who reported having IBM. In the PD+IBM group, the number of body position changes was significantly lower than in PD-IBM (0.4/h [0.0-1.8] vs 1.4/h [0.0-4.6], P=.015). Sleep efficiency (SE) was lower in PD+IBM patients (63.5; 26.2-85.6) compared to PD-IBM patients (78.4; 54.8-92.6; P<.001). CONCLUSION: PD patients who report IBM have fewer sleep-related body position changes (i.e., nocturnal hypokinesia) than PD patients without such concerns. Furthermore, objective SE is significantly diminished in these patients.

Nocturnal hypokinesia and sleep quality in Parkinson's disease.

OBJECTIVES: To study the relationship between nocturnal hypokinesia and sleep quality in Parkinson's disease (PD). DESIGN: Questionnaire study using intergroup analysis. SETTING: Parkinson Centre Nijmegen, a tertiary university referral center. PARTICIPANTS: Two hundred forty individuals with Parkinson's disease. MEASUREMENTS: Clinical and demographic data were obtained. Nocturnal hypokinesia was assessed using Question 35 of the Parkinson's Disease Quality of Life Questionnaire and rated on a 5-point Likert scale (1 = all of the time to 5 = never). The Pittsburgh Sleep Quality Index (PSQI) was used to quantify sleep quality, higher scores indicating poorer sleep quality. RESULTS: One hundred thirty-five of 240 participants had difficulties turning over in bed. Mean PSQI scores were significantly higher in participants with nocturnal hypokinesia (7.7 ± 4.1) than in those without (6.1 ± 3.4, P = .001). A regression model correcting for age, disease duration, and Hoehn and Yahr stage showed a significant influence of nocturnal hypokinesia on sleep quality (coefficient of determination = 0.042, standardized-beta = 0.163, P = .03). There was a linear relationship between frequency of nocturnal hypokinesia and sleep quality. CONCLUSION: This is the first study that documents that nocturnal hypokinesia negatively affects sleep quality in PD. Nocturnal hypokinesia therefore merits therapeutic attention, including optimal nighttime dopaminergic treatment and education about turning strategies in bed.

Recognition and diagnosis of sleep disorders in Parkinson's disease.

Sleep disturbances are among the most frequent and incapacitating non-motor symptoms of Parkinson's disease (PD), and are increasingly recognized as an important determinant of impaired quality of life. Here we review several recent developments regarding the recognition and diagnosis of sleep disorders in PD. In addition, we provide a practical and easily applicable approach to the diagnostic process as a basis for tailored therapeutic interventions. This includes a stepwise scheme that guides the clinical interview and subsequent ancillary investigations. In this scheme, the various possible sleep disorders are arranged not in order of prevalence, but in a 'differential diagnostic' order. We also provide recommendations for the use of sleep registrations such as polysomnography. Furthermore, we point out when a sleep specialist could be consulted to provide additional diagnostic and therapeutic input. This structured approach facilitates early detection of sleep disturbances in PD, so treatment can be initiated promptly.

Sleep benefit in Parkinson's disease: time to revive an enigma?

Some patients with Parkinson's disease (PD) reportedly experience 'sleep benefit': an improved motor functioning upon awaking in the morning. In this questionnaire study, 114 out of 243 consecutive outpatients with PD (46.9%) subjectively experienced sleep benefit. Among those patients that regularly took an afternoon nap, 33.7% experienced sleep benefit after the nap as well. Between patients with and without sleep benefit, there were no differences in demographic or clinical variables, including age, disease duration, dopaminergic treatment, and nocturnal sleep quality. Sleep benefit remains an intriguing but elusive phenomenon, which deserves renewed attention and further research.

[Nocturnal stridor in multiple system atrophy]. / Nachtelijke stridor bij multipele systeematrofie.

BACKGROUND: Multiple system atrophy is a neurodegenerative disorder with parkinsonism, cerebellar ataxia and autonomic dysfunction. The occurrence of nocturnal stridor in patients with multiple system atrophy is associated with a decreased life expectancy. This is what makes adequate treatment so important. Nevertheless, stridor goes often unrecognized and there is frequent uncertainty about the therapeutic options. CASE: We present a 58-year-old woman with multiple system atrophy and nocturnal stridor. Direct laryngoscopy showed bilateral paresis of the vocal cords and glottic stenosis. Since the outcome of treatment with continuous positive airway pressure (CPAP) was unsatisfactory, a tracheotomy was performed after which the stridor disappeared. CONCLUSION: Polysomnography and laryngoscopy are the important diagnostic tools for this condition, after the clinical interview. Tracheotomy used to be the only therapeutic option for stridor. However, recent studies show a comparable effectiveness of non-invasive treatment with CPAP, provided there is a correct indication. The choice of therapy is a multidisciplinary process in which the neurologist, the sleep medicine specialist, the otolaryngologist, and the patient are involved.

[Parkinsonism due to the medication]. / Stijf van de pillen. Parkinsonisme door medicatie.

Parkinsonism is an extrapyramidal disorder characterised by tremor, muscle rigidity, bradykinesia and postural instability. The most common cause of parkinsonism is idiopathic Parkinson disease. Another common cause is drug-induced parkinsonism. Various drugs can cause parkinsonian symptoms. Many patients exhibiting these side-effects are mistakenly treated with dopaminergic medication. We present two patients with drug-induced parkinsonism induced by sodium valproate and cinnarizine, respectively. The symptoms disappeared after they stopped taking this medication.