Cluster headache and the nervus intermedius.
D003027:Cluster Headache / Q000503:physiopathology*; D005154:Facial Nerve / Q000503:physiopathology*; D006801:Humans; D010275:Parasympathetic Nervous System / Q000503:physiopathology; D014653:Vascular Headaches / Q000503:physiopathology*