Are modified Fisher Scale and bleeding pattern helpful predictors of neurological complications in non-aneurysmal subarachnoid hemorrhage?

PURPOSE Non-aneurysmal subarachnoid hemorrhage (NA-SAH) is a clinical-radiological entity with a different prognosis than aneurysmal SAH (A-SAH). The purpose of this study is to assess the predictive value of the modified Fisher Scale (mFS) for neurological complications in patients with this diagnosis. METHODS We recruited patients admitted at our hospital services between 2009 and 2017 who were diagnosed with spontaneous SAH, with either perimesencephalic (PM-SAH) or diffuse pattern (D-SAH), an initial negative angio-CT, and at least one digital subtraction angiography of brain vessels discarding underlying brain aneurysms or other vascular malformations. RESULTS The retrospective observational study included 116 patients. The mean age was 54.4, and the sample included predominantly male subjects (62.9%). Hunt and Hess (HH) scores on admission ranged from 3 to 5 in 18.1% of patients. The prevalence of hydrocephalus requiring ventricular drainage was 18.1%. The prevalence of symptomatic vasospasm was 4.3%. A modified Rankin Scale (mRS) 0-2 at discharge was found in 95.6%. In a multivariate logistic regression for the presence of neurological complications including age, sex, admission HH 3-5 compared with 2, the only significant predictors were mFS 4 compared with mFS < 4 (OR 4.47 (95% CI 1.21, 16.66) p value = 0.03) and D-SAH compared with PM-SAH (OR 7.10 (95% CI 1.24, 40.8) p value = 0.03). CONCLUSION In patients with NA-SAH, a mFS score of 4 and/or a D-SAH bleeding pattern in non-contrast cranial CT on admission predicted the development of relevant neurological complications.