Red flags for a secondary headache include thunderclap onset, fever and meningismus, papilloedema, unexplained focal neurological signs, unusual headache attack precipitants, and headache onset after age 50. The yield of neuroimaging in patients with typical recurrent migraine attacks is very low. Any imaging study, particularly MRI, can identify incidental findings of no clinical significance which may lead to patient anxiety and further unnecessary investigation. For patients with typical migraine and a normal clinical examination who desire reassurance, careful explanation of the diagnosis and patient education may be more advisable.
Sources:
Becker WJ, et al. Guideline for primary care management of headache in adults. Can Fam Physician. 2015 Aug;61(8):670-9. PMID: 26273080.
Elliot S, et al. Why do GPs with a special interest in headache investigate headache presentations with neuroradiology and what do they find? J Headache Pain. 2011 Dec;12(6):625-8. PMID: 21956455.
Howard L, et al. Are investigations anxiolytic or anxiogenic? A randomised controlled trial of neuroimaging to provide reassurance in chronic daily headache. J Neurol Neurosurg Psychiatry. 2005 Nov;76(11):1558-64. PMID: 16227551.
Sempere AP, et al. Neuroimaging in the evaluation of patients with non-acute headache. Cephalalgia. 2005 Jan;25(1):30-5. PMID: 15606567.
Related Resources:
Patient Pamphlet: Imaging Tests for Headaches: When you need them and when you don’t