Nonaneurysmal subarachnoid hemorrhage.: Study of long-term follow-up

Introduction. Nonaneurysmal subarachnoid hemorrhage (SAH) accounts for 15% to 20% of all the cases of SAH. Its prognosis may vary from complete recovery to different and serious complications. We describe a series of cases with nonaneurysmal SAHs, their clinical and tomographic characteristics and causes as well as long term prognosis. Patients and methods. 50 patients diagnosed of SAH and two negative brain angiographies for aneurysm were followed-up for an average period of 62 months. The demographic data of importance, vascular risk factors, were recorded. They were evaluated during the acute phase with the Hunt and Hess clinical scale and Fisher topographic scale. The distribution of the hemorrhage was listed as absent, perimesencephalic, focal, ventricular or diffuse. Presence of rebleeding, death and the functional course, measured by the Rankin modified scale, were recorded during the follow-up. According to this scale, Rankin of 0 to 2 was considered as a favorable prognosis. Results. This series represents 8.6 of all the SAH cases in our hospital. In 6 cases (12%), there was a causal relationship between the use of sympathicomimetic drugs and the development of SAH. In 80% of them, it was not possible to document the cause of the hemorrhage, while different causes (cerebral venous thrombosis in 4 [8%], spontaneous dissection of the vertebral artery in 2 [4%], vasculitis secondary to neurocysticerosis in 2 [4%], cavernous angioma in 1 [2%] and spinal arteriovenous malformation in 1) were found. Rebleeding did not occur in any of the cases and only one patient died. In 45 patients (90%), the final functional prognosis was good (Rankin 0-2). We found no significant differences between the tomographic pattern of the hemorrhage, initial clinical condition and long term prognosis. Conclusions. Our findings show a low frequency of nonaneurysmal SAH in our population and a diversity of causes greater than those reported by other series. The good functional prognosis in these cases was confirmed.