1. Headache Classification Committee of the International Headache Society (IHS). The International Classification of Headache Disorders, 3rd edition. Cephalalgia 2018;38:1-211.
2. Sandrini G, Friberg L, Coppola G, Jänig W, Jensen R, Kruit M, et al. Neurophysiological tests and neuroimaging procedures in non-acute headache (2nd edition). Eur J Neurol 2011;18:373-381.
3. National Clinical Guideline Centre. Headaches: Diagnosis and Management of Headaches in Young People and Adults. London (UK): National Institute for Health and Clinical Excellence (NICE); 2012,Sep; p. 38(Clinical Guideline; no.150).
4. Headache Classification Subcommittee of the International Headache Society. The International Classification of Headache Disorders: 2nd edition. Cephalalgia 2004;24(Suppl 1):9-160.
5. Lepage R, Krebs L, Kirkland S, Alexiu C, Campbell S, Rowe B. MP25: the role of advanced imaging in the management of benign headaches in the emergency department: a systematic review. CJEM 2017;19:S73
6. Williams A, Friedman BW. The yield of non-contrast cranial computed tomography for the detection of intracranial pathology in emergency department patients with headache: a systematic review. Ann Emerg Med 2014;64:S48
7. Vernooij MW, Ikram MA, Tanghe HL, Vincent AJ, Hofman A, Krestin GP, et al. Incidental findings on brain MRI in the general population. N Engl J Med 2007;357:1821-1828.
8. Weber F, Knopf H. Incidental findings in magnetic resonance imaging of the brains of healthy young men. J Neurol Sci 2006;240:81-84.
9. Alons IM, van den Wijngaard IR, Verheul RJ, Lycklama à Nijeholt G, Wermer MJ, Algra A, et al. The value of CT angiography in patients with acute severe headache. Acta Neurol Scand 2015;131:164-168.
10. Rizk B, Platon A, Tasu JP, Becker CD, Mendes Pereira V, Perneger T, et al. The role of unenhanced CT alone for the management of headache in an emergency department. A feasibility study. J Neuroradiol 2013;40:335-341.
11. Beithon J, Gallenberg M, Johnson K, Kildahl P, Krenik J, Liebow M, et al. Diagnosis and Treatment of Headache. Bloomington (MN): Institute for Clinical Systems Improvement (ICSI); 2013.
12. Scottish Intercollegiate Guidelines Network. Diagnosis and Management of Headache in Adults. Edinburgh: NHS Quality Improvement Scotland; 2008.
14. Detsky ME, McDonald DR, Baerlocher MO, Tomlinson GA, McCrory DC, Booth CM. Does this patient with headache have a migraine or need neuroimaging? JAMA 2006;296:1274-1283.
16. Frishberg BM, Rosenberg JH, Matchar DB, McCrory DC, Pietrzak MP, Rosen TD, et al. Evidence-Based Guidelines in the Primary Care Setting: Neuroimaging in Patients with Nonacute Headache. St Paul, MN: US Headache Consortium; 2000.
17. Tsushima Y, Endo K. MR imaging in the evaluation of chronic or recurrent headache. Radiology 2005;235:575-579.
18. Kim SY, Park JE, Seo HJ, Lee YJ, Jang BH, Son HJ, et al. NECA’s Guidance for Undertaking Systematic Reviews and Meta-Analyses for Intervention. Seoul: National Evidence-based Healthcare Collaborating Agency; 2011.
19. Hoy D, Brooks P, Woolf A, Blyth F, March L, Bain C, et al. Assessing risk of bias in prevalence studies: modification of an existing tool and evidence of interrater agreement. J Clin Epidemiol 2012;65:934-939.
20. Higgins J, Green S. Cochrane handbook for systematic reviews of interventions Version 5.1. 0. The Cochrane Collaboration. Confidence Intervals; 2011.
21. Hwang SD. Meta-Analysis Using R. Seoul: Hakgissa; 2015.
22. Cooper JG, Smith B, Hassan TB. A retrospective review of sudden onset severe headache and subarachnoid haemorrhage on the clinical decision unit: looking for a needle in a haystack? Eur J Emerg Med 2016;23:356-362.
23. Cooney BS, Grossman RI, Farber RE, Goin JE, Galetta SL. Frequency of magnetic resonance imaging abnormalities in patients with migraine. Headache 1996;36:616-621.
25. Carstairs SD, Tanen DA, Duncan TD, Nordling OB, Wanebo JE, Paluska TR, et al. Computed tomographic angiography for the evaluation of aneurysmal subarachnoid hemorrhage. Acad Emerg Med 2006;13:486-492.
27. Ziegler DK, Batnitzky S, Barter R, McMillan JH. Magnetic resonance image abnormality in migraine with aura. Cephalalgia 1991;11:147-150.
28. Chen SP, Fuh JL, Lirng JF, Chang FC, Wang SJ. Recurrent primary thunderclap headache and benign CNS angiopathy: spectra of the same disorder? Neurology 2006;67:2164-2169.
30. Ross JS, Masaryk TJ, Modic MT, Ruggieri PM, Haacke EM, Selman WR. Intracranial aneurysms: evaluation by MR angiography. AJR Am J Roentgenol 1990;155:159-165.
31. Alons IME, Goudsmit BFJ, Jellema K, van Walderveen MAA, Wermer MJH, Algra A. Yield of computed tomography (CT) angiography in patients with acute headache, normal neurological examination, and normal non contrast CT: a meta-analysis. J Stroke Cerebrovasc Dis 2018;27:1077-1084.
33. GBD 2015 Neurological Disorders Collaborator Group. Global, regional, and national burden of neurological disorders during 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet Neurol 2017;16:877-897.
34. Cortelli P, Cevoli S, Nonino F, Baronciani D, Magrini N, Re G, et al. Evidence-based diagnosis of nontraumatic headache in the emergency department: a consensus statement on four clinical scenarios. Headache 2004;44:587-595.
35. Bethel J, McInulty L. Subarachnoid haemorrhage: case study and literature review. Emerg Nurse 2010;18:22-26.
36. Steiner T, MacGregor E, Davies P. Guidelines for All Healthcare Professionals in the Diagnosis and Management of Migraine, Tension-Type, Cluster and Medication-Overuse Headache. 3rd Edition. Hull: British Association for the Study of Headache; 2007.