2019 年 112 巻 5 号 p. 303-307
Duane retraction syndrome (DRS) is a congenital eye-movement disorder that shows limited outward gaze, retraction of the eye and partial closure of the eyelid on gazing inwards. There are additional symptoms such as inferior rolling disturbances and up and down deviation (upshoot, downshoot) when gazing inwards. The cause of DRS is presumed to be associated with the absence of the abduction nerve and abnormal innervation of the oculomotor nerve. Various combined malformations have been reported in DRS, but there are few reports of inner ear malformations. We report herein on a case of DRS with inner ear malformations.
A 55-year-old man had been suffering from repeated vertigo attacks. He had right hearing loss and diplopia from childhood. The examination in our hospital showed bilateral limited outward gaze, partial closure of eyelid on gazing inwards, horizontal pendulum like nystagmus on gazing left and right, and right superior sensory hearing loss. Temporal bone target CT and MRI revealed hypoplasty of the right semicircular canal and right cochlear malformation of the incomplete partition type I, and aplasia of the left semicircular canal. In addition, the bilateral vestibule was a common cavity and the left cochlea was normal. Thus, we diagnosed DRS and bilateral inner ear malformation.