main features of the benign paroxysmal positional vertigo ( b.p.p.v . ) are : latency before the onset of vertigo , nystagmus of the rotatory type beating toward the lower ear , nystagmus tires out , nystagmus gets inverted when the head is brought back to orthostatism , nystagmus is reproducible as many times as the position is taken .
C0155502
benign paroxysmal positional vertigo
C0042571
vertigo