Orofacial migraine and neurovascular orofacial pain-new insights into characteristics and classification

Orofacial migraine (OFM) and neurovascular orofacial pain (NVOP) are both recognized as migraine-related entities affecting the facial and orofacial regions, according to the International Classification of Orofacial Pain (ICOP). However, the distinction between these two conditions and the question of whether NVOP should be considered a separate entity remain subjects of ongoing debate. The aim of this study is to compare the diagnostic characteristics of OFM and NVOP to reassess whether they should continue to be classified as two distinct diagnoses. The cohort comprised 75 patients, 12 males and 63 females, 40 were diagnosed as NVOP and 35 as OFM according to ICOP criteria. Patients were recruited from the tertiary orofacial pain clinic in Hadassah Medical Center between the years 2016 to 2023. NVOP and OFM patients did not differ in age, sex, pain intensity and other pain characteristics. However, OFM patients have significantly more cranial autonomic signs (36.4%) than NVOP patients (10.3%), and also more migraine symptoms such as nausea and photophobia. (68.6% vs. 41%) OFM patients reported significantly more awakening from sleep (52.9%) than NVOP patients (26.3%). Also, OFM pain was concomitant with headache in about two third of cases (66.7%), compared to only a third (30.8%) of NVOP cases. Most NVOP patients have pain that mimics toothache (85%), rarely detected in OFM (11.4%). The diagnostic features of OFM and NVOP indicate that there are many similarities between the two. But also, unique features that allows for separating OFM and NVOP into two distinct diagnostic entities, in accordance with the ICOP classification. Inclusion of patients with associated headaches enhanced this separation, and suggests expanding the definition of ICOP and include it under OFM and NVOP. At present there is justification to maintain the separate ICOP classifications of NVOP and OFM, particularly for research purposes.