The Relationship Between Obstructive Sleep Apnea and Ruptured Intracranial Aneurysms

Aneurysmal subarachnoid hemorrhage occurring during sleep: Clinical characteristics and risk factors

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is known to be triggered by several specific human activities. Sleep, by contrast, has not been considered a triggering activity for aSAH, and clinical characteristics of patients who sustain aSAH during sleep have rarely been reported in the literature.

METHODS

This is a retrospective analysis on the data acquired through a multicenter aSAH registry. Between January 2019 and December 2021, a total of 732 aSAH patients had been registered into our database. After excluding 109 patients whose activities at aSAH onset had been unidentifiable, the remaining 623 aSAH patients were dichotomized to 59 patients who sustained aSAH during sleep (Sleep group) and 564 patients who sustained aSAH during daytime activities (Awake group). Two-group comparison of demographic variables and multivariate logistic regression analysis were performed to clarify their clinical characteristics and identify potential risk factors.

RESULTS

The Sleep group exhibited significantly higher frequencies of diabetes (15.5 % vs. 6.4 %, p = 0.01) and antiplatelet use (13.8 % vs. 4.6 %, p=0.004) than the Awake group. Furthermore, multivariate logistic regression analysis showed that diabetes (OR, 3.051; 95 % CI, 1.281-7.268; p = 0.012) and antiplatelet use (OR, 3.640; 95 % CI, 1.422-9.316; p = 0.007) were correlated with aSAH occurring during sleep. There were no significant inter-group differences in the patient outcomes evaluated at discharge.

CONCLUSION

The current results indicate that risk factors may exist for aSAH occurring during sleep. Further investigations on how comorbidities such as diabetes, antiplatelet use and sleep apnea affect human hemodynamic and hemostatic parameters during sleep is warranted to better understand those relationships.

Obstructive Sleep Apnea and Its Influence on Intracranial Aneurysm

Obstructive sleep apnea syndrome (OSAS) is associated with cerebrovascular disease, which can lead to life-threatening outcomes. The purpose of the study was to investigate the relationship between OSAS and comorbid intracranial aneurysms. We retrospectively reviewed 564 patients who underwent a polysomnography and brain magnetic resonance angiography as part of their health checkup. We calculated the prevalence of an intracranial aneurysm and OSAS in patients and measured the size of the intracranial aneurysm if present. The mean patient age was 55.6 ± 8.5 years, and 82.3% of them were men. The prevalence of an intracranial aneurysm in patients with OSAS was 12.1%, which is significantly higher than patients with non-OSAS (5.9%, p = 0.031). Patients with OSAS had a much higher prevalence of intracranial aneurysms, after adjusting all possible confounding factors such as age, sex, smoking status, alcohol drinking, and body mass index (odds ratio: 2.32; 95% confidence interval: 1.07-5.04). Additionally, the OSAS group had noticeably larger aneurysms compared with those of the non-OSAS group (3.2 ± 2.0 mm vs. 2.0 ± 0.4 mm, p = 0.013). We found a significant association between OSAS and intracranial aneurysms. OSAS could be another risk factor for the development of intracranial aneurysms.

Assessment of balloon remodeling techniques in endovascular treatment of wide-neck intracranial aneurysms (WN-IAs)

OBJECTIVES

To evaluate the clinical, technical, and angiographic results in endovascular management of wide-neck intracranial aneurysms (WN-IAs) using the balloon-remodeling technique.

METHODS

This study was a prospective, single-center study that was carried out over a period of three years from January 2019 to December 2021 at the Neuro-Interventional Unit at our hospital. Patients who presented with WNIAs and were eligible for endovascular treatment using the balloon-remodeling approach were included in the study.

RESULTS

We included 37 patients with a mean age of 49.7 ± 12.3 years. About 91.9% of the participants had SAH, 5.4% had unruptured aneurysms, and 2.7% had intracranial hemorrhage. The mean time to treatment was 6.97 ± 7.35 days, the mean aneurysm diameter was 5.7 ± 1.7 mm, and the mean neck diameter was 3.8 ± 1.0 mm. The majority of the patients had a dom-to-neck ratio of less than 2 (89.2%). We have used hyper form balloons in 48.6%, hyper glide in 43.2%, Copernic balloons in 5.4%, and eclipse in 2.7%. According to the Raymond-Roy occlusion classification, 86.5% of the patients had complete obliteration, 10.8% had residual neck, and 2.7% had a residual aneurysm. Almost 91.9% had no complications, 2.7% had ischemia, and 5.4% had mild rupture by wire, treated by 5 min hyperinflation of the balloon till hemorrhage stopped.

CONCLUSIONS

Balloon-assisted detachable coiling is an important option in the treatment of WN-IAs. We found that this technique allowed safe and efficient treatment of aneurysms when conventional treatment had failed due to WN. Endovascular coiling using the balloon remodeling technique of wide neck showed a high technical success rate and good short-term clinical outcomes. A good selection of patients with WN-IAs treated by endovascular coiling using balloon remodeling technique and a good selection of materials used help in decreasing the complications.

Obstructive sleep apnea aggravates neuroinflammation and pyroptosis in early brain injury following subarachnoid hemorrhage via ASC/HIF-1α pathway

Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage. However, the underlying mechanism remains unclear. In this study, we established a mouse model of subarachnoid hemorrhage using the endovascular perforation method and exposed the mice to intermittent hypoxia for 8 hours daily for 2 consecutive days to simulate sleep apnea. We found that sleep apnea aggravated brain edema, increased hippocampal neuron apoptosis, and worsened neurological function in this mouse model of subarachnoid hemorrhage. Then, we established an in vitro HT-22 cell model of hemin-induced subarachnoid hemorrhage/intermittent hypoxia and found that the cells died, and lactate dehydrogenase release increased, after 48 hours. We further investigated the underlying mechanism and found that sleep apnea increased the expression of hippocampal neuroinflammatory factors interleukin-1β, interleukin-18, interleukin-6, nuclear factor κB, pyroptosis-related protein caspase-1, pro-caspase-1, and NLRP3, promoted the proliferation of astrocytes, and increased the expression of hypoxia-inducible factor 1α and apoptosis-associated speck-like protein containing a CARD, which are the key proteins in the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway. We also found that knockdown of hypoxia-inducible factor 1α expression in vitro greatly reduced the damage to HY22 cells. These findings suggest that sleep apnea aggravates early brain injury after subarachnoid hemorrhage by aggravating neuroinflammation and pyroptosis, at least in part through the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.

Aneurysm size and blood pressure severity in patients with intracranial aneurysms and sleep apnea

STUDY OBJECTIVES

Obstructive sleep apnea is a risk factor for hypertension. Hypertension is associated with aneurysm formation, growth, and rupture of intracranial aneurysm (IA). Retrospectively, symptoms of obstructive sleep apnea are more prevalent in patients with IAs. Studies investigating the prevalence and effect of objectively measured sleep apnea in these patients are sparse. We report on the baseline data of an ongoing prospective study. We cross-sectionally analyzed whether obstructive sleep apnea was associated with larger IAs and increased need for antihypertensive medications in a population of patients with unruptured IA.

METHODS

130 adult (≥ 18 years) patients with unruptured IAs were recruited. Patients with ischemic stroke or intracranial hemorrhage within 3 months prior to screening were excluded. We assessed obstructive sleep apnea by full-night respiratory polygraphy. Aneurysm size and antihypertensive medication-as a surrogate parameter for the severity of hypertension-were compared between patients with and without obstructive sleep apnea (apnea-hypopnea index >5 events/h). Aneurysm growth and rupture rate were retrospectively analyzed.

RESULTS

101 patients completed the study protocol. Obstructive sleep apnea was diagnosed in 68.0% (17) of male and 34.2% (26) of female participants and associated with more severe hypertension (1.536 ± 0.2 vs 0.74 ± 0.1 drugs; P = .01) and larger aneurysms (6.9 ± 1.0 vs 3.8 ± 0.5 mm; P = .01).

CONCLUSIONS

Patients with obstructive sleep apnea had more antihypertensive medication and larger IAs, probably due to accelerated aneurysm growth. Sleep apnea should be considered in patients with IAs. More research is needed to investigate the effects of sleep apnea on IAs and aneurysm outcome.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Incidence and Effects of Sleep Apnea on Intracerebral Aneurysms-IESA Study; URL: https://clinicaltrials.gov/ct2/show/NCT02880059; Identifier: NCT02880059.

CITATION

Zaremba S, Albus L, Hadjiathanasiou A, Vatter H, Wüllner U, Güresir E. Aneurysm size and blood pressure severity in patients with intracranial aneurysms and sleep apnea. J Clin Sleep Med. 2022;18(6):1539-1545.

Modifiable risk factors for intracranial aneurysms: Evidence from genetic studies

Background:

Intracranial aneurysm (IA) is a crucial health concern with limited strategies for prevention and treatment.

Aim:

To identify potentially modifiable risk factors, such as socioeconomic, behaviors, dietary, and cardiometabolic factors, for IA and its subtypes.

Methods:

Summary statistics for IA were derived from a genome-wide association study with an overall 79,429 participants. Single nucleotide polymorphisms associated with modifiable risk factors at genome-wide significance ( P = 5 × 10–8) were used as instrumental variables. The inverse-variance-weighted method, weighted-median method, Mendelian randomization (MR)-Egger regression, MR-Pleiotropy RESidual Sum and Outlier, and multivariable MR analyses were performed to evaluate the effect estimates.

Results:

Genetically predicted educational attainment, insomnia, smoking, and systolic and diastolic blood pressure (SBP and DBP) were significantly associated with the risk of IA. The odds ratios (ORs) were 0.44 (95% confidence interval (CI): 0.37–0.52) for educational attainment, 1.15 (95% CI: 1.08–1.23) for insomnia, 1.56 (95% CI: 1.38–1.75) for smoking initiation, 2.69 (95% CI: 1.77–4.07) for cigarette per day, 2.65 (95% CI: 1.72–4.08) for lifetime smoking, 1.07 (95% CI: 1.06–1.09), and 1.06 (95% CI: 1.04–1.10) for SBP and DBP, respectively. Similar effect estimates were observed for unruptured IAs and aneurysmal subarachnoid hemorrhage.

Conclusions:

This study provided genetic evidence that several modifiable risk factors, including blood pressure, smoking, educational attainment, and insomnia were associated with the risk of IA.

Intermittent hypoxia mimicking obstructive sleep apnea aggravates early brain injury following ICH via neuroinflammation and apoptosis

Spontaneous intracerebral hemorrhage (ICH) is a subtype of stroke associated with high mortality and morbidity due to the lack of effective therapy. Obstructive sleep apnea (OSA) has been reported to aggravate early brain injury (EBI) and worsen the overall outcome of patients with ICH. However, the precise role of OSA-mediated neuroinflammation and apoptosis following ICH has not been confirmed. The present study aimed to investigate the neuronal damage induced by OSA and the potential molecular mechanisms by which ICH-induced EBI regulates neural apoptosis in a C57BL/6 mouse ICH model. Mortality, neurological score, brain water content and neuronal death were evaluated by Evans blue extravasation, TUNEL staining, ELISA, analysis of reactive oxygen species/lipid peroxidation and western blotting. The results showed that OSA induction decreased survival rate, neurological score and neuron survival and upregulated the protein expression levels of Caspase-3, Bax, cytokines IL-1β, IL-6 and TNF-α and NF-κB, which indicated that OSA-mediated induction of apoptosis and neuroinflammation aggravated neuronal death following ICH. The molecular mechanism was partly dependent on the activating transcription factor/CHOP pathway. Taken together, the results demonstrated that OSA worsens neurological outcomes in mice and increases neuronal death by enhancing neural apoptosis and neuroinflammation.