Evaluating HIV-infected patients with headache: who needs computed tomography?

OBJECTIVE: To empirically test a clinical prediction rule for evaluating HIV-infected patients complaining of headache and to identify those at low risk for intracranial mass lesion who do not need immediate computed tomography of the head. DESIGN: Two retrospective clinical cohorts of HIV-infected patients clinically evaluated for headache. METHODS: To describe the headache clinical outcomes, medical records were abstracted from all HIV-infected patients evaluated for headache with computed tomography of the head at two urban hospitals. Patients were categorized as low, intermediate, or high risk based on clinical criteria (focal neurological signs, altered mental status, history of seizure) and immune status (CD4 lymphocytes < or =200 microL). Records were abstracted from a second unselected cohort of HIV-infected outpatients with headache who were all treated and followed in primary care (N=101). RESULTS: Of 101 unselected HIV-infected outpatients followed in primary care after headache, 1% (95% confidence interval [CI], 0% to 6%) had a treatable intracranial lesion. Of 364 HIV-infected patients with headache sent for evaluation with computed tomography of the head, the rate of any abnormality was zero in the low-risk group (95% CI, 0% to 10%; n=35); 9% in the intermediate-risk group (95% CI, 2% to 16%; n=242); and 21% in the high-risk group (95% CI, 12% to 29%; n=87). CONCLUSION: Most HIV-infected patients with headache may be treated with analgesics and followed up clinically. Those without focal neurological signs, altered mental status, seizure, or decreased CD4 lymphocytes are unlikely to have intracranial mass lesions.