<qa>  What is the name of the study that involves a retrospective analysis of blood samples?To date, there is no commercially available blood test approved in the United States for use as an aid in the assessment and diagnosis of stroke. There have been various reports in the scientific literature describing the ability of various biomarkers to predict or identify stroke, with varied success. A biomarker panel approach, similar to that used for the evaluation of chest pain patients troponin I, CK-MB, and myoglobin enhances diagnostic accuracy, particularly when the panel includes protein markers associated with various components of the disease pathophysiology. This study involves a retrospective analysis of data collected from patients that present with an acute focal neurological deficit, suspected cerebral ischemia, or suspected intracranial hemorrhage within 24 hours of symptom onset or last known well time will be enrolled into the study. Blood samples will be collected at enrollment and serially up to 72 hrs. from the time of onset or last known well time. The study population will also include a subset of patients with subarachnoid hemorrhage, who will have additional samples collected daily from day 3 through day 14 at clinical sites participating in the vasospasm substudy for the evaluation of cerebral vasospasm. The patients participation in the study is complete when all samples have been collected or when they are discharged from the hospital, whichever occurs first. All blood sample will be analyzed using the Triage Stroke Panel test. Measurements will be performed at each clinical site and at Biosite subject to test device availability. In order to minimize bias and eliminate significant risk to the patient, physicians will be blinded to all Triage Stroke Panel results during the course of the study. Completed case report forms CRFs and frozen plasma samples will be transferred to Biosite. 