Treatment and outcomes of non-aneurysmal perimesencephalic subarachnoid haemorrhage: A 5 year retrospective study in a tertiary care centre

Abstract

PurposePerimesencephalic Subarachnoid Haemorrhage (PMSAH) is an uncommon type of SAH. Severity of PMSAH can be graded by the presence of blood in the Sylvian fissure. No study compares the outcomes from PMSAH with blood present or absent in the Sylvian fissure. Furthermore, the use of Nimodipine lacks evidence base in PMSAH. We investigated whether continuing Nimodipine to 21 days in PMSAH with or without blood in the Sylvian fissure made any significant difference to patient outcome. MethodsRetrospective study of 93 cases admitted to tertiary centre from 2016 to 2020. We compared prevalence of cases with blood in Sylvian fissure, and analysed outcomes including complications and changes to patient modified rankin scale (MRS). We also audited use of Nimodipine in these cases and analysed whether Nimodipine made any significant difference in preventing complications. Results91 % of PMSAH were grade 1, 24 cases (26 %) had blood in the Sylvian fissure. Sylvian fissure positive (Sylvian-positive) cases were statistically significantly more likely to have higher rates of complication compared to Sylvian fissure negative (Sylvian-negative) cases. Our centre stopped Nimodipine 56 % of the time in Sylvian-negative cases and 45 % of the time in Sylvian-positive cases. There was no statistically significant difference in outcomes when Nimodipine was continued to 21 days or ceased after negative angiogram; this result extended to both Sylvian-positive and Sylvian-negative subgroups when directly comparing Sylvian-positive cases with each other and Sylvian-negative cases likewise. DiscussionSylvian-positive cases have a significantly higher rate of complication, as well as an increase in MRS. This may be because of the inflammatory properties of haemoglobin in the subarachnoid space post-bleed. Furthermore, acknowledging the limitations of our retrospective data, we did not find a statistically significant difference in continuing Nimodipine to 21 days with relation to PMSAH outcomes in all subgroups.