Idiopathic subarachnoid hemorrhage: Pattern and long-term outcome

To analyze the presentation characteristics of idiopathic subarachnoid hemorrhage (SAHi), its characteristics and its long-term evolution.

Descriptive follow-up study. ICU in Hospital of III level. SAH admitted to the ICU with negative admission arteriography during the years 2007-2022. The main variables of interest were demographic data, prognostic and severity scales, ICU evolution data, radiological results, exitus and GOSE scale (Glasgow Outcome Scale Extended) until the last observation.

Seven hundred thirty-threepatients with SAH were admitted to the ICU, 149 with initial negative arteriography. After the verification test starting at 3 weeks, 114 patients (16.1%) remained without underlying lesion. 58.8% were male and the age was 57.1±12.8 years. If we compare SAH with vs without underlying lesion (SAHi), we observed differences in the male sex (38.7% vs 58.8%), Hunt-Hess [2 (2-4) vs 2 (1-2)], Fisher [4 (3-4) vs 3 (2-4)], mechanical ventilation (86.8% vs 21.1%), tracheostomy (24.9% vs 1.8%), ICU stay days [10 (5-21) vs 3 (2-5)] and ICU deaths (20.9% vs 1%). We followed up on SAHi: 70,5 (33-109) months, with mortality of 11.4% (13 patients), none to related causes. There has been no rebleeding or late brain injury. In survivors, the GOSE was 7 (7-8), with 82.3% of patients with GOSE between 5-8. 44.7% of the patients had perimesencephalic SAH, with a mortality in the follow-up period of 7.8% and GOSE 7 (6-8).

SAH without underlying vascular lesion presents good results in terms of morbidity and mortality and long-term functional status, improving if it is a perimensencephalic SAH.