Emergency computed tomography in patients with first seizure

To determine the frequency of emergent imaging findings on head computed tomography (CT) in an adult population of first seizure (FS) patients presenting to an emergency department (ED); and to search for associations between clinical features and emergent imaging findings among these patients.

For this retrospective registry-based study, adult FS patients presenting to Helsinki University Hospital ED in 2006 were identified based on ICD-10 diagnosis. Clinical parameters were extracted from patient records. A neuroradiologist blinded to clinical information reviewed the CT scans for emergent imaging findings prompting changes in acute treatment, predefined as intracranial haemorrhage, acute ischemia, central nervous system infection, mass effect, midline shift, obstructive hydrocephalus and/or brain oedema.

449 FS patients were identified, of which 416 (93%) had undergone emergency CT imaging. Of these, 49 (12%) had emergent imaging findings on non-contrast CT. Logistic regression suggested that headache (odds ratio (OR) 3.62, 95% confidence interval (CI) 1.30-10.12), focal motor sign in the ED (OR 3.23, 95% CI 1.58-6.62), history of malignancy (OR 3.05, 95% CI 1.17-7.92), and altered mental state in the ED (OR 2.27, 95% CI 1.15-4.49) were associated with emergent imaging findings on NCCT. Presence of at least one of these factors had 84% sensitivity for emergent imaging findings.

In FS patients, clinical information can be used to guide imaging decisions in the ED. However, if emergency imaging is not performed, urgent outpatient imaging and pre-imaging follow up should be secured.