耳鼻科ジャーナル

A 7-Year-Old Boy with Light Cupula of the Horizontal Semicircular Canal

Hiroaki Ichijo

A 7-Year-Old Boy with Light Cupula of the Horizontal Semicircular Canal

Report of childhood positional vertigo is very rare. We present a 7-year-old boy who revealed persistent direction-changing geotropic positional nystagmus. In the supine position, horizontal nystagmus toward the left continued as long as the position was maintained. However, it ceased when the head was turned to the right side by 45º. With greater head turn (right-ear-down), nystagmus toward the right lasted for more than 1 minute. In the left-ear-down position, horizontal nystagmus toward the left occurred and lasted for more than 1 minute. After the disappearance of positional nystagmus, we detected canal paresis of the right ear by caloric test. We considered that the pathophysiology of the persistent type of geotropic nystagmus is a result of light debris cupulolithiasis of the horizontal canal.