Blood Pressure and Risk of Subarachnoid Hemorrhage in China

Background and Purpose- Subarachnoid hemorrhage (SAH) has a high case fatality rate and young mean age at onset compared with other types of stroke, but the pathogenesis of SAH is not fully understood. We examined associations of systolic and diastolic blood pressure with incident nontraumatic SAH in a large prospective study in China. Methods- In 2004 to 2008, 512 891 adults (59% women) from the general population were recruited into the CKB study (China Kadoorie Biobank). Participants were interviewed, measured, and followed up for fatal and nonfatal events. After excluding those with prior vascular disease, Cox regression analysis was used to relate blood pressure to incident SAH events. Analyses were adjusted for major confounders and corrected for regression dilution to give associations with long-term average blood pressure. Results- At baseline, mean age was 51 (SD, 11) years, and mean systolic blood pressure/diastolic blood pressure was 130.6/77.6 (SD, 21.0/11.1) mm Hg. During 3.5 million person-years of follow-up, there were 553 incident SAH cases (mean age at event, 61 [SD, 11] years), yielding an overall annual incidence rate of 12.9 per 100 000. Higher average levels of blood pressure were linearly and positively associated with higher risks of incident SAH: a 10 mm Hg higher systolic blood pressure and a 5 mm Hg higher diastolic blood pressure were associated with hazard ratios for SAH of 1.21 (95% CI, 1.13-1.29) and 1.20 (95% CI, 1.12-1.28), respectively. There was no evidence that the hazard ratios varied by age or sex or by levels of other vascular risk factors. Elevated blood pressure (systolic blood pressure, >120 mm Hg) accounted for 23% of all SAH cases. Conclusions- The incidence of SAH in China was comparable with estimates from Western populations. Higher levels of blood pressure were positively associated with higher risks of SAH, and elevated blood pressure accounted for about a quarter of all SAH cases.

Cervical spine arteriovenous fistula associated with hereditary haemorrhagic telangiectasia

Reported is a case of a man aged 55 years who presented with progressive spastic paraparesis. Examination demonstrated multiple cutaneous telangiectases. Subsequent development of upper limb weakness, acute urinary retention and eventual respiratory compromise resulted in the requirement for intensive care unit admission and mechanical ventilation. MRI spine revealed diffuse T2 hyperintensity in the cervical cord with enhancement and cord expansion. Immunomodulatory therapy for a presumed diagnosis of transverse myelitis yielded no response, so a vascular aetiology was suspected. Spinal angiography demonstrated an arteriovenous fistula involving the upper cervical cord. Endovascular embolisation was successfully performed and a marked clinical improvement was achieved. Cervical arteriovenous fistulas can cause progressive myelopathy, subarachnoid haemorrhage and brainstem dysfunction. Management typically comprises endovascular embolisation or surgical interruption. A clinical diagnosis of hereditary haemorrhagic telangiectasia was also made in this case, and spinal arteriovenous fistula formation has been associated with this condition.