ICOP trigeminal autonomic orofacial pain hemifacial continuous pain with autonomic symptoms 2025-07-07T17:27:44Z While no isolated facial equivalent of 3.4 Hemicrania continua, described in International Classification of Headache Disorders 3rd Edition,, has so far been clearly established, extension of pain into the face in hemicrania continua has been described. Thus, pain referral and/or radiation to oral and/or facial structures may cause diagnostic difficulties. ICOP number: 5.3.4 PMID:32103673 Ava E. Cunningham