A 66 year old woman presents to her General Practitioner after a fall. She describes that the episode was preceded by the onset of dizziness while hanging out washing. She fell and had difficulty getting back up. She vomited twice but was not incontinent and did not bite her tongue. Her symptoms have improved gradually, but have recurred abruptly over the few days since the first episode. On examination she is well, but certain head movements provoke her symptoms and induce nystagmus. What is the most likely diagnosis?
1) Benign paroxysmal positional vertigo (BPPV)
2) Labyrinthitis
3) Meniere's disease
4) Vestibular migraine