A 70-year-old woman has suffered attacks of sharp, stabbing pain on the right side of her nose, cheek, lower eyelid, upper lip, upper jaw, teeth and gums, lower jaw, teeth and gums and lower lip. Occasionally she has had severe, brief and stabbing pain felt as a headache around her right eye, forehead and upper eyelid. The pain often leaves her with uncontrollable facial twitching. These sudden attacks of pain last only a few seconds but seem to the patient. This initial impression should include a brief discussion of the main anatomical structures implicated in the case, and how they may be connected to some of the symptoms presented in the case scenario. The initial impressions of the scenario may or may not change after collaboration in small groups. 3 differential diagnoses..