Figure 2From: Light cupula of the horizontal semicircular canal occurring alternately on both sides: a case reportThe instance of light cupula observed in the left hSCC. The patient’s head and the magnified left hSCC were viewed from the top of the patient’s head. (A) In the supine position, a left-beating nystagmus (maximal SPV = 19°/s) was persistently observed due to an utriculofugal deflection of the cupula. (B) When the patient’s head was turned to the right side, the left hSCC was inhibited because of the utriculofugal deflection of the cupula resulting in a persistent right-beating nystagmus (maximal SPV = 38°/s). (C) When the head was turned to the left side, the cupula of the left hSCC was deflected utriculopetally, which caused a persistent left-beating nystagmus (maximal SPV = 10°/s). Note that the intensity of the nystagmus is stronger in right-head rolling than in left head-rolling. hSCC, horizontal semicircular canal; SPV, slow-phase velocity.Back to article page