Loss of consciousness at the onset of subarachnoid hemorrhage has been strongly associated with global cerebral edema and worse Hunt and Hess scores on admission to the hospital, and should therefore be taken as a marker of early brain injury with serious implications, according to research published in JAMA Neurology.
The researchers also found that loss of consciousness (LOC) during subarachnoid hemorrhage (SAH) was associated with a 2.8-fold increased risk of death or severe disability at 1 year.
LOC is one of the most common symptoms of SAH, and previous research has examined symptoms that present at the beginning of hemorrhage and their long-term effects on survival and recovery. For this study, Sureerat Suwatcharangkoo, MD, of Columbia University Medical Center in New York and Mahidol University in Bangkok, Thailand, and colleagues attempted to determine LOC’s effects at the onset of SAH, complications during hospitalization, and outcome at 1 year.
The researchers retrospectively analyzed 1,460 patients with SAH with a mean age (SD) of 55 (15) years who were prospectively enrolled in the Columbia University SAH Outcomes Project (SHOP) between 1996 and 2012. Analysis was done between 2013 and 2015.
Among the 1,460 patients, 590 (40.4%) lost consciousness at onset of SAH. Among 443 of these patients whose LOC duration was recorded, 169 (38.1%) lost consciousness for less than 10 minutes, 93 (21.0%) for 10 to 60 minutes, and 181 (40.9%) for longer than 60 minutes. The longer the period of unconsciousness, the worse the Hunt and Hess scores upon hospital admission. If LOC lasted less than 10 minutes, the risk of presenting with a Hunt and Hess score of 4 or 5 was only 16.0% and 6.5%, respectively; if LOC lasted more than 60 minutes, the risk was 21.5% and 67.4%, respectively.