Diagnostic yield of head computed tomography for the hospitalized medical patient with delirium.

BACKGROUND Delirium is common in hospitalized patients and warrants early diagnosis and treatment. Often the evaluation of delirium includes head computed tomography imaging. However, in hospitalized medical patients, the yield of head computed tomography is unknown. OBJECTIVE To determine the diagnostic yield of head computed tomography when evaluating a hospitalized medical patient with delirium in the absence of a recent fall, head trauma, or new neurologic deficit. DESIGN AND SETTING Retrospective medical record review at a large academic medical center in Boston, Massachusetts. PARTICIPANTS We reviewed all medical records for head computed tomography scans performed from January 2010 through November 2012 in patients on the general medicine or medical subspecialties units. MAIN OUTCOMES A "positive" head computed tomography was defined as an intracranial process that could explain delirium. An "equivocal" head computed tomography was defined as the presence of a finding of unclear significance in relation to delirium. RESULTS There were 398 patients hospitalized for >24 hours who underwent head computed tomography for delirium. Two hundred twenty head computed tomography studies met eligibility criteria, with 6 (2.7%) positive and 4 (1.8%) equivocal results. All positive and equivocal findings resulted in change in management. CONCLUSIONS The diagnostic yield of head computed tomography in determining the cause of delirium in hospitalized patients is low. Due to the low rate of positive findings, head imaging is unnecessary in the majority of cases of delirium. However, there may be a subset of high-risk individuals in which head imaging is indicated.