Dix-hallpike maneuver: the patient is positioned on the examination table in such a way that when he/she is placed supine, the head extends over the edge. the patient is lowered with the head supported and turned 45 degrees to one or the other side. the eyes are carefully observed; if no abnormal eye movements are seen, the patient is returned to the upright position.this same maneuver is repeated with the head in the opposite direction and the patients symptoms are noted.the pattern of response consists of the following:1. nystagmus is a combination of vertical upbeating & rotatory (torsional) beating towards the downward eye. pure vertical nystagmus is not seen in bppv.2. there is often a latency of onset of nystagmus3. duration is less than a minute4. vertiginous symptoms are invariably seen5. nystagmus disappears with repeated testing (fatiguability)6. symptoms often recur with the nystagmus in opposite direction on return of the head to upright position.