Nonaneurysmal Subarachnoid Hemorrhage: A Review of Clinical Course and Outcome in Two Hemorrhage Patterns

Linda L. Herrmann; Joseph M. Zabramski


J Neurosci Nurs. 2007;39(6):135-142. 

In This Article

Natural History

The findings of several important studies have guided clinicians in the management of patients with NASAH. These studies evaluated differ-ences in outcome and prognosis in patients with ASAHs, versus NASAHs, particularly those with the perimesencephalic pattern of hemorrhage.

Brismar and Sundbarg (1985) retrospectively analyzed 127 patients who presented with angiographically negative SAH from 1968 to 1978. Average follow-up time was 5.4 years. Among these patients, two fatal rebleeds (1.5%) occurred within 5 days of the initial hemorrhage. A third patient died within the second week, following elevated ICP and cerebral ischemia. Five patients died after hospital discharge, from 2 to 7 years after hemorrhage; these deaths were related to cardiac disease and malignancy, and none of these patients had any documented neurological deficits at discharge. Of the remaining 119 patients, the authors found that 94% (n = 112) returned to at least part-time work and 82% (n = 98) resumed usual activities an average of 2 weeks after the hemorrhage. These findings supported previous research by Hayward (1977), who found that, at 1 year after hemorrhage, 95% of patients with NASAH had returned to at least part-time employment, and 68% had returned to their usual activities (n = 51).

Van Gijn and colleagues (1985) compared the clinical presentation and outcome in 92 patients with ASAH to that in 28 patients with angiographically negative NASAH. In the NASAH group, 13 patients (46%) had a perimesencephalic pattern of hemorrhage on their admission CT scan. The authors noted that headache onset was more gradual in patients with NASAH. In the ASAH group, 28 patients (30%) died as a result of their hemorrhage, and 20 of the 64 survivors (31%) experienced significant residual deficits. In contrast, clinical outcome was good in all 28 patients with angiographically negative NASAH.

Other groups have confirmed these findings, emphasizing the more gradual onset of severe headache in NASAH patients compared to the "thunderclap" headache that accompanies aneurysm rupture, and the benign clinical course, particularly in patients with the perimesencephalic pattern of SAH (Brilstra et al., 1997; Rinkel et al., 1990; Rinkel, Wijdicks, Vermeulen, et al., 1991; van Gijn et al., 1985). Perhaps even more important, these authors and others have reported that the risk of recurrent hemorrhage in patients with NASAH is extremely low, essentially equivalent to that of the general population (Alexander et al., 1986; Brismar & Sundbarg, 1985; Rinkel et al., 1990; Rinkel, Wijdicks, Hasan, et al., 1991; Rinkel, Wijdicks, Vermeulen, et al., 1991; van Gijn et al.).