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 < 3, mFS 4 compared with mFS < 4, D-SAH compared with PM-SAH, and mRS score at discharge of 0-2 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.