Nontraumatic Subarachnoid Hemorrhage Along The Cortical Convexity: Report Of 10 Cases And A Pooled Analysis Of 237 Cases

Background and Objective: Nontraumatic subarachnoid hemorrhage along the cortical convexity(c SAH) is a rare type of subarachnoid bleeding(SAH), in which haemorrhage is localized to one or a few cortical sulci at the convexity of the brain without spread into the sylvian fissure, the interhemispheric fissure, the basal cisterns or the ventricles,also called cortical SAH, sulcal SAH. There are a few reports on c SAH in our country until now. In this paper, we present a collection of 10 cases of c SAH and analyize their clinical manifestations,imaging features,etiology and prognosis. Simultaneously, a pooled analysis of 237 c SAH cases was carried on that literature reported including morbidity, etiologies, clinical presentation, imaging findings, treatment and outcome. The aim of this paper is to enhance the awareness of this disease and guide clinical practice afterward.Methods:We reviewed the medical records of ten patients with c SAH that admitted from July 2012 to November 2013 in Department of Neurology, the General Hospital of Shenyang Military Command. The clinical data, neuroimaging findings and follow-up data of them were retrospectively analyzed. At the same time, search of the Pub Med and CBM electronic databases from 2004 through 2014 and the relevant articles reviewed. A total of 237 cases from 26 articles as a independent sample consisting of the interrelated clinical demographics was collected in this pooled analysis, together with the literature to explore the etiology and pathogenesis, imaging characteristics, treatment, and prognosis.Results: There were eight men and two women aged from 53 to 82 years. Six patients had transient focal neurological symptoms, focal neurologic deficits was the second most common symptom, vertigo was unusual;two patients with moderate headache. Cranial CT in all patients showed linear hyperdensities localized at one or more cortical sulci at the convexity of the brain. Fluid-attenuated inversion recovery and susceptibility weighted imaging also had positive expression in nine patients. The known etiologies of 10 cases included cerebral amyloid angiopathy(n=4), middle cerebral artery stenosis/occlusion(n=4), cerebral venous sinus thrombosis(n=1), intracarotid artery serious stenosis(n=1) For one-month follow-up, the neurologic deficits had varying degrees of recovery in nine patients, and the hemiplegia unchanged in only one case. Meanwhile, the pooled analysis from 237 case showed that cerebral amyloid angiopathy, reversible cerebral vasoconstriction syndrome, cerebral venous thrombosis, intracarotid artery stenosis/occlusion as well as posterior reversible encephalopathy syndrome accounted for 66.67% of all etiologies. The common symptoms included headache in various degrees, TIA like symptoms, focal neurologic deficits as well as the seizures.Conclusion: c SAH is a special type of SAH and different from aneurysmal SAH in the etiology, clinical presentation and imaging features. The patients with c SAH always had favourable outcome with neurologic deficits rarely leave behind and low recurrence. The comprehensive cerebrovascular screening should be conducted for new patients with c SAH.