Early cerebral infarction following aneurysmal subarachnoid hemorrhage: frequency, risk factors, patterns, and prognosis.

Early cerebral infarction (ECI) following aneurysmal subarachnoid hemorrhage (aSAH) remains poorly understood. This study aims to determine the frequency and risk factors of this special episode, as well as to assess the relationship between its patterns and outcome. We retrospectively enrolled 243 patients who underwent aneurysm treatment within 60 hours of SAH. ECI was defined as one or more new hypodense abnormalities on computed tomography within 3 days after SAH, rather than lesions attributable to edema, retraction effect, and ventricular drain placement. Risk factors were tested by multivariate analysis. The infarct was classified by an established grading system (single or multiple, cortical or deep or combined). Poor outcome was defined as the Glasgow Outcome Score of severe disability or worse. Sixty-five patients (26.7%) had early infarction. Acute hydrocephalus (odds ratio [OR] 6.67; 95% confidence interval [CI] 1.59-27.95), admission plasma glucose level (OR 1.42 per mmol/L; 95% CI 1.16-1.73), and treatment modality (OR 16.27; 95% CI 4.05-65.28) were independent predictors of ECI. The pattern was single cortical in 19 patients (29.2%), single deep in 9 (13.8%), multiple cortical in 8 (12.3%), multiple deep in 14 (21.5%), and multiple combined in 15 (23.1%). ECI was associated with delayed cerebral infarction (DCI) (P = 0.002) and poor outcome (P < 0.001). Multiple combined infarction was related to poor outcome (P = 0.001). In summary, the occurrence of ECI, which is associated with surgical treatment, acute hydrocephalus and high admission plasma glucose, may potentially predict DCI and unfavorable outcome. Further studies are warranted to reveal the underlying mechanisms of this event and thereby minimize it.