Computerized tomography of the brain for elderly patients presenting to the emergency department with acute confusion

Objective: Confusion is a common reason for presentation of elderly patients to the ED. There are many potential causes of confusion, which include acute neurological events. Computerized tomography (CT) scans are often routinely ordered to investigate confusion, despite the recommendation of guidelines against routine use. The aim of the present study was to determine the usefulness of CT brain scans in a prospective cohort of confused elderly patients presenting to an ED. Methods: The progress notes of 106 consecutive patients over 70 years of age who had a CT brain scan for a presentation of acute confusion were reviewed for indications for the scan and the presence of neurological examination findings. Official radiology reports of CT brain scans were assessed for the presence of abnormalities. Results: Of the 106 patients, 12 (11%, 95% CI 5.29-17.35) had no documented neurological examination. Fifteen patients (14%, 95% CI 7.51-20.79) had acute abnormalities on CT scan, one of whom had two abnormalities. There were ten acute ischaemic strokes, four cerebral haemorrhages and two meningiomas. Thirteen of the patients with positive CT findings (93%, 95% CI 80.7-105.96) had new findings on neurological examination. The only patient with no neurological findings with a positive CT scan had had a fall. A history of a fall or the presence of neurological findings on examination was predictive of a positive CT scan (odds ratio 17.07, 95% CI 2.15-135.35). Conclusion: The results add further support to guidelines that suggest that CT scans of the brain for confused elderly patients should only be performed for those with acute neurological findings, head trauma or a fall.