How to diagnose a new type of vertigo
Neurologists from South Korea have identified a new type of vertigo that responds to treatment.
Called recurrent spontaneous vertigo (RSV), the condition has no known cause but is characterised by a marked susceptibility to motion sickness and prolonged nystagmus.
To identify RSV, doctors can administer a simple head-shaking manoeuvre by moving the patient's head forward then shaking horizontally for about 15 seconds in a dark room.
A video recording is then taken of eye movements and the time constant measured to determine how the reflexive