[Neuroimaging guidelines in nonacute headaches]

The Treatment Guideline Subcommittee of the Taiwan Headache Society evaluated the indication of neuroimaging for nonacute headache according to the principles of evidence-based medicine. We have assessed the qualities of studies, levels of evidence, and referred to other guidelines proposed by Western countries. After several panel discussions, we merged opinions from the subcommittee members and proposed a Taiwan consensus. Neuroimaging is not necessary for patients with nonacute and recurrent migraine or tension-type headache when there is no recent change of headache characteristics and neurological examinations are normal. Neuroimaging is suggested for patients who have headaches with abnormal neurological examinations. For patients who are diagnosed as having cluster headache and have never received neuroimaging studies, or patients whose headache characteristics are atypical for cluster headaches, neuroimaging studies should be considered. Neuroimaging is also recommended for patients with cough headache, exertional headache and headache associated with sexual activity. Although the resolution of MRI is superior to CT, evidence is insufficient to make recommendation regarding the choice of MRI or CT for the evaluation of nonacute headache patient. Clinicians should make a judgment by themselves according to the patient's specific conditions.