Human Electrophysiological Model to Quantify the CGRP-related Axon Reflex of Trigeminal Afferents

Inclusion Criteria: Healthy volunteers (Study Arm 1 and 2): * age ≥ 18 years * good German language skills * no history of head trauma * no history of neurologic disease * no primary headache disorder (e.g. migraine, episodic or chronic tension type headache, cluster headache) * no regular drug intake (except for oral contraceptives) Migraine patients need to match the following criteria (Study Arm 2 and 3): * age ≥ 18 years * good German language skills * fulfilling the diagnostic criteria for either episodic or chronic migraine with or without aura according to the international classification of headache disorders (ICHD) 3rd edition * history of migraine \> 1 year * keeping a headache diary for a minimum of 3 months prior to the study Exclusion Criteria: Healthy volunteers and migraine patients under the following conditions will be excluded: * Chronic pain syndromes (e.g. low back pain, osteoarthritis, painful neuropathy, rheumatoid arthritis) * Acute pain (e.g. pain due to acute skin injury, menstrual pain, acute toothache). In this case, a measurement can only be performed after complete remission of pain and at least 48 hours after intake of acute pain medication (e.g. triptans, non-steroidal anti-inflammatory drug (NSAID)). * history of treatment with agents targeting the CGRP pathway (e.g. erenumab) \< 3 months before the study * history of treatment with Botulinum toxin \< 9 months before the study * Diseases of the skin involving the skin at face and forehead * Pregnancy or breast feeding * Subjects lacking capacity for consent