Sleep-related hypoventilation and hypercapnia in multiple system atrophy detected by polysomnography with transcutaneous carbon dioxide monitoring

Prevalence and impact of sleep-related breathing disorder in multiple system atrophy patients: a cross-sectional study and meta-analysis

Objective

Sleep-related breathing disorder (SRBD) is a prevalent non-motor symptom in multiple system atrophy (MSA). However, the reported prevalence of SRBD in MSA from different studies has shown inconsistency. Additionally, only one study has examined the impact of SRBD on both motor and non-motor symptoms in MSA.

Methods

Cross-sectional study of 66 patients with probable MSA from China. SRBD was ascertained with polysomnography (PSG). All the MSA individuals were assessed using the Epworth Sleepiness Scale (ESS), Unified Multiple-System Atrophy Rating Scale (UMSARS), Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), the Mini-mental State Examination (MMSE), Non-Motor Symptoms Scale (NMSS), and Pittsburgh Sleep Quality Index (PSQI). Moreover, a meta-analysis was conducted by searching studies related to MSA and SRBD in PubMed, Web of Science, Embase, and Cochrane databases. Data were pooled as necessary to calculate prevalence of SBRD with 95% confidence intervals (CI).

Results

Our study included 66 patients with MSA, 52 of whom had a diagnosis of SRBD (78.8%). There were no significant differences between the MSA with SRBD and without SRBD groups on the age, sex, disease onset, disease duration, UMSARS I, II, and IV, the NMSS, the HAMA, HAMD, the ESS the FSS, the MMSE, and the PSQI scales. However, MSA patients with SRBD having a significant higher obstructive apnea index and percentage of snoring during sleep than MSA patients without SRBD [10.0 (4.1-10.6) vs. 0.1 (0-0.3), and 8.3 (5.1-12.2) vs. 4.2 (0-7.5)]. Also, between the two groups, the mean and minimum oxygen concentrations during sleep were lower in MSA patients with SRBD than in those without SRBD [93.7 (93-95) vs. 95.5 (95.8-97), p = 0.001] and [83.9 (81.2-89.0) vs. 90.3 (89.8-93.3), p = 0.000]. The primary search strategy identified 701 articles, with 10 meeting the inclusion criteria. The overall prevalence of SRBD in a combined sample of 295 MSA patients was found to be 60.5% (95% CI, 43.2-76.5%). Further analysis revealed that the prevalence of SRBD in MSA patients in Asia was 79.2% (95% CI, 54.7-96.3%), which was higher than that in Europe (41.6, 95% CI, 32-51.5%).

Conclusion

The study found a prevalence of 78.8% of SRBD in MSA patients, with a notably higher prevalence in Asia compared to Europe. The majority of SRBD cases in MSA were attributed to obstructive apnea. Furthermore, the presence of SRBD did not show a significant impact on the motor and non-motor symptoms of MSA patients.

Detection of episodic nocturnal hypercapnia in patients with neurodegenerative disorders

PURPOSE

Episodic nocturnal hypercapnia (eNH) in transcutaneous carbon dioxide pressure (PtcCO2) corresponding to rapid eye movement sleep hypoventilation is a useful biomarker for detecting nocturnal hypoventilation. However, the relationship between eNH and neurodegenerative diseases with sleep-related breathing disorders (SRBDs) is unknown. The aim of this study was to evaluate the relationship between eNH and nocturnal hypoventilation in neurodegenerative diseases.

METHODS

Patients with neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), multiple system atrophy (MSA), Parkinson's disease, progressive supranuclear palsy, corticobasal syndrome, and idiopathic normal pressure hydrocephalus, were enrolled and received overnight PtcCO2 monitoring. The patients were divided into groups for eNH and sleep-associated hypoventilation (SH) prevalence analysis: A (ALS), B (MSA), and C (others).

RESULTS

Among 110 patients, twenty-three (21%) and 10 (9%) of the patients met eNH and SH criteria, respectively. eNH and SH were significantly more frequent in groups A and B than in C. The prevalence of SH in the patients with eNH was 39% whereas most of patients with SH (90%) presented with eNH. Among patients with daytime carbon dioxide pressure in arterial blood ≤ 45 mmHg, eNH frequency was 13%, whereas none of the patients met SH criteria. The frequency of noninvasive positive pressure ventilation after PtcCO2 monitoring was significantly higher in those with than without eNH.

CONCLUSIONS

eNH is common in patients with MSA and ALS who present with SRBD. eNH with overnight PtcCO2 monitoring is a useful biomarker to detect hypoventilation among neurodegenerative diseases with different SRBD mechanisms.

Neurologic Disorders in Women and Sleep

Sleep disorders in women remain underrecognized and underdiagnosed mainly because of gender bias in researching and characterizing sleep disorders in women. Symptoms of common sleep disorders are frequently missed in the general female population and are expected to be further overlooked because of overlapping symptoms in women with neurologic disorders. Given the bidirectional relationship with sleep and neurologic disorders, it remains critical to be aware of the presentation and impact of sleep disorders in this patient population. This article reviews available data on sleep disorders in women with neurologic disorders and discusses their distinctive features.