[The initial loss of consciousness in spontaneous subarachnoid hemorrhage. What does it mean?]

Poor outcome and rebleeding, after admission to hospital of patients with spontaneous subarachnoid hemorrhage (SAH) has been found to be predicted by loss of consciousness at ictus (LOCi). In this study, we assessed the clinical and neuro-radiological significance of the LOCi in non-traumatic SAH.

The authors retrospectively studied 102 patients with SAH admitted to S. João Hospital between January 1, 1989 and December 31, 1992, who were divided into two groups with and without LOCi and compared according to clinical and imaging features.

Loss of consciousness at ictus was statistically associated with an age over 52 years (odds ratio, 2.9; 95% confidence interval, 1.1-7.8); a Hunt and Hess Scale score > ou = 3 (4.4; 1.6-12.3); finding of subarachnoid blood on initial cranial CT scan (5.5; 1.4-26.3); existence of aneurysm (3.4; 1.3-8.9); a Glasgow Outcome Scale score > ou = 3 (4.69; 1.6-14.1). A poor clinical condition on admission (5.2;1.8-14.5) and existence of aneurysm (4.1; 1.6-10.6) were the only two findings shown to have an independent power of significant association with loss of consciousness at ictus, using logistic regression analysis, with LOCi as a dependent variable.

In this study, LOCi has independent predictive power for a poor neurologic condition on admission and for the finding of aneurysm on angiogram. Loss of consciousness at ictus may be explained by the direct impact of the initial hemorrhage on the brain from a large tear in the aneurysmal wall, causing a quick rise in intracranial pressure (with LOCi) but a relatively short bleeding time.