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Long‐Term Outcome in Patients with Subarachnoid Hemorrhage with Negative CT Scan

Despite improvements in diagnostic imaging, the initial interpretation of third-generation head CT scans to detect subarachnoid hemorrhage (SAH) has not reached 100% sensitivity [1,2]. The proportion of patients with SAH and a negative CT scan was 3.3% within 0 to 3 days of onset and 3.0% within 4 to 14 days of onset [3]. Another study showed that the proportion of patients with SAH and a negative CT may be close to 7% within 3 days [4].This indicates that SAH with a negative CT scan is not rare. Recurrent hemorrhage remains a serious consequence of aneurysmal SAH, with a fatality rate of approximately 70%, but it may be the most preventable cause of poor outcomes [5]. However, the recently published guidelines by the American Heart Association do not clear and definie the long-term outcome for patients who have SAH with a negative CT scan [5].This study addresses the longterm outcomes of SAH with a negative CT scan. A prospective study of outcomes of consecutive patients with SAH with a negative CT scan from January 1995 to September 2009 was commenced at a university teaching hospital in China. Twenty-eight patients included in the study did not have SAH visible on head CT, and the diagnosis of SAH was based on the results of a lumbar puncture (LP) with the xanthrochromia of the cerebrospinal fluid. Patients with spontaneous aneurysmal and nonaneurysmal SAH were included. Individuals with SAH caused by trauma, traumatic taps, arteriovenous malformation or other secondary causes were excluded. A cerebral angiography was performed within 3–5 days after admission in some patients. We divided these patients into two groups based on whether they agree or rejected angiography: an angiography group and a nonangiography group. Nine of 17 patients of the angiograpphy group showed an aneurysmal pattern of hemorrhage. In addition to eight patients for surgery therapy, the other one patient was not to receive surgery therapy. Those patients who were surviving 30 days after onset of the initial SAH were followed continuously. Rehemorrhage after the initial SAH was defined as a sudden headache with or without coma, and the new bleed was confirmed by head CT or LP. Follow-up was begun on October 10, 2009. Patients or their surrogates were interviewed either by telephone or in person. Subarachnoid hemorrhage and data regarding any rehemorrhages include the date, postmortem reports, and imaging data. Global outcome and functional status were assessed with the modified Rankin Scale (mRS = 0–6; 0 = no symptoms or disability; 6 = dead). Data for the survival and rehemorrhage analyses were extracted in April 2010. Data for the overall death and rehemorrhage analyses were compiled for the initial hospitalization after the primary SAH and from the date of the first SAH until the end September of 2009. A P value <0.05 was considered to be statistically significant. Twenty-eight patients who underwent an initial SAH with a negative CT were enrolled during their first hospitalization. One (fatal rehemorrhage) of 11 patients in the nonangiography group died during the first hospitalization. Therefore, the 27 remaining patients were enrolled and contacted for further follow-up. Table 1 shows the baseline characteristics of the patients in this study. As of April 2010, there were 15 survivors in the angiography group (including the eight patients for surgery therapy) and five survivors (except one lost to follow-up and four died) in nonangiography group. The rate of complete loss of follow-up was