Role of bioclimate conditions on cerebral aneurysm rupture in the Brittany region of France

Global Disparities in the Presentation and Management of Aneurysmal Subarachnoid Hemorrhage: A Review and Analysis

OBJECTIVE

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with high mortality rates. There is a significant gap in the literature describing global disparities in demographics, management, and outcomes among patients with aSAH. We aimed to conduct a systematic review and meta-analysis to assess global disparities in aSAH presentation and management.

METHODS

PubMed and Embase databases were queried from earliest records to November 2022 for aSAH literature. Presentation, demographics, comorbidities, treatment methods, and outcomes data were collected. Articles that did not report aSAH-specific patient management and outcomes were excluded. Pooled weighted prevalence rates were calculated. Random effects model rates were reported.

RESULTS

After screening, 33 articles representing 10,553 patients were included. The prevalence of Fisher grade 3 or 4 aSAH in high- and lower-income countries (HIC and LIC), respectively, was 79.8% (P < 0.01) and 84.1 (P < 0.01). Prevalence of male aSAH patients in HIC and LIC, respectively, was 35.8% (P < 0.01) and 45.0% (P < 0.01). Prevalence of treatment in aSAH patients was 99.5% (P < 0.01) and 99.4% (P = 0.16) in HIC and LIC, respectively. In HIC, 35% (P < 0.01) of aneurysms in aSAH patients were treated with coiling. No LIC reported coiling for aSAH treatment; LIC only reported rates of surgical clipping, with a total prevalence of 92.4% (P < 0.01) versus 65.6% (P < 0.01) in HIC.

CONCLUSION

In this analysis, we found similar rates of high-grade SAH hemorrhages in HIC and LIC but a lack of endovascular coil embolization treatments reported in LIC. Additional research and discussion are needed to identify reasons for treatment disparities and intervenable societal factors to improve aSAH outcomes worldwide.

Association of Global Ultraviolet Radiation With the Incidence of Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND OBJECTIVES

Inflammation is a key pathomechanism for growth and rupture of intracranial aneurysms. Anti-inflammatory mechanisms may reduce rupture of intracranial aneurysms and the incidence of aneurysmal subarachnoid hemorrhage (SAH). Ultraviolet (UV) radiation from sunlight exposure induces systemic anti-inflammatory responses through immunosuppressive mechanisms. We studied whether SAH incidence is associated with UV radiation.

METHODS

Global SAH incidence, time trends, and regional differences from 32 countries were linked to UV radiation data from the Tropospheric Emission Monitoring Internet Service. Odds between low vs high UV exposure and SAH incidence were calculated. Correlation analysis was performed using R (R 4.1.2).

RESULTS

SAH incidences ranged from 1.3 to 27 per 100 000 patient-years (p-y) and UV index from 1.76 to 11.27. The correlation coefficient (rho) between SAH incidence and UV index was -0.48 (P = .012). SAH incidence was highest in Japan (13.7-27.9 p-y) with an UV index 6.28. UV index was highest in Chile 11.27 with a lower SAH incidence (3.8-4.8 p-y). The lowest UV index 1.76 was seen in Iceland with higher SAH incidence (9.8 p-y).Within Europe, regions with higher UV indices reported lower SAH incidences (Northwest Europe: SAH incidence p-y 8.61/UV index 2.85; Southeast Europe: SAH incidence p-y 7.37/UV index 4.65) with a significant inverse correlation (rho = -0.68, P = .004) and not a significant correlation between non-European countries (rho = -0.43, P = .19). Low exposure of UV radiation in global regions predicted higher than median incidences of SAH with an odds ratio 5.13 (95% CIs 1.02-31.5).

CONCLUSION

The incidence of SAH is inversely associated with UV radiation. Further studies should assess the actual UV exposure in relation to SAH incidence and potential biological explanations for the relation we found.