Neuroimaging in stroke and seizure as neurological emergencies (NISSAN) study

OBJECTIVE: To report the current national utilization of neuroimaging in the emergency department for the two most common neurological emergencies; stroke and seizure. METHODS: Patients were identified using primary International Classification of Diseases (ICD)-9-CM codes from the 2004 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS is designed to collect data on the utilization and provision of care in emergency departments of hospitals in the United States. We analyzed the use of neuroimaging in patients presenting to the emergency department with seizure or stroke. RESULTS: About 60% of 1,190,219 patients with the diagnosis of stroke or seizure had neuroimaging performed emergently. Patients with any type of stroke were more likely to undergo neuroimaging compared to patients with seizure (78% vs. 37%, P <.05). When stroke subtypes were analyzed separately, neuroimaging was performed in the emergency department among 100% of patients with subarachnoid hemorrhage, 79% with ischemic stroke, and 69% with intracerebral hemorrhage. CONCLUSIONS: In a nationally representative study, emergent neuroimaging appeared to be underutilized among patients with ischemic stroke and intracerebral hemorrhage. There is a need to increase the utilization of neuroimaging in the emergency department in anticipation of new acute stroke treatments.