Objective: To evaluate the impact of the introduction of the International Headache Society (IHS) criteria on the use of neuroimaging for headache diagnosis in a specialist outpatient center.
Background: The general indications for neuroimaging in headache are a matter of debate. International Headache Society criteria should improve diagnostic accuracy, consequently reducing the use of expensive diagnostic procedures such as brain CT or MRI scan.
Methods: We reviewed the medical records of all 2739 new patients seen in our center from 1984 to 1996, analyzing the records of those patients who underwent neuroimaging before or after the introduction of the IHS criteria in 1988.
Results: There were no differences in the number of CT scans ordered in the period before (6.04%) or after (6.06%) the introduction of the IHS criteria. Only 12 scans revealed significant abnormalities, probably unrelated to headache.
Conclusions: These results suggest that the yield of CT scanning patients seen in a headache clinic is very low, even when alarm signs are present notwithstanding strict adherence to dignostic criteria. An improved definition of secondary forms of headache might help to reduce this adjunctive cost to the care of patients with headache in a headache clinic.