Cupulolithiasis of the horizontal semicircular canal
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Hiroaki Ichijo
- چاپ و سال / کشور: 2011
Description
To clarify whether positional nystagmus of horizontal cupulolithiasis contains vertical and torsional components, and to quantify the asymmetry, we analyzed nystagmus in four positions (healthy-ear-down, affectedear- down, supine, nose-down), using 3-dimensional video-oculography. Subjects were 20 patients with direction- changing apogeotropic positional nystagmus, 11 females and 9 males, with a mean age of 58.1 years. Nystagmus was recorded using an infrared camera and the findings were converted to digital data. Using ImageJ, we performed 3-dimensional video-oculography and measured maximum slow-phase velocity (MSV) of three components. Positional nystagmus was not purely horizontal. Eleven (55%) patients revealed a vertical component, and 14 (70%) patients had a torsional component in the healthy- ear-down position. The mean value of MSV of the horizontal component in the healthy-ear-down position was 18/s and that in the affected-ear-down position was 7.8/s. For the horizontal component, MSV in the healthy-eardown position was significantly greater than that in the affected-ear-down position (p\0.01). These results suggest that vertical and torsional components occur from the horizontal semicircular canal, and the response to ampullopetal bending is more than two times as strong as that to ampullofugal bending
Eur Arch Otorhinolaryngol, Received: 20 January 2011 / Accepted: 14 March 2011 Springer-Verlag 2011
