Move the patient's head in a way that moves endolymph through the semicircular canals and triggers vertigo in patients with BPPV, check patient can do the manoeuvre safely, patient sits upright with head turned 45 degrees, rapidly lower patient backwards until head is hanging off end of couch extended 20-30 degrees, hold head still, watch eyes for 30-60 seconds for nystagmus, repeat with head turned other way, in BPPV the manoeuvre will trigger rotational nystagmus and vertigo symptoms