Table 3. Cases with different diagnosis by ICHD-3β and explanations.

ICHD-3β code	Subtypes of headache according by ICHD-3β	Cause of change in diagnosis	No. of patients
1.3	Chronic migraine	Headache ≥ 15 days/M, with ≥ 8 of those days meeting criteria for migraine	17
		Permission of diagnosis with medication overuse headache	30
		Permission of migraine with aura	2
4.2	Primary exercise headache	Relaxation of the criteria for headache characteristics or duration	5
4.7	Primary stabbing headache	Deletion of the criteria about the first division of the trigeminal nerve	114
4.8	Nummular headache	New diagnostic criteria	1
4.	Probable other primary headache, cough/exercise/external pressure headache/PSH/NPDH	Addition of probable diagnostic criteria	37
6.7.3.1	Headache probably attributed to RCVS	Addition of the probable diagnostic criteria	7
7.3.2	Headache attributed to aseptic meningitis	Addition of a criterion, "viral meningitis or encephalitis has been diagnosed" in 9.1	6
11.5.2	Headache attributed to chronic or recurring rhinosinusitis	New diagnostic criteria	4

4PSH, primary stabbing headache; NPDH, new daily persistent headache; RCVS, reversible cerebral vasoconstriction syndrome.