Positional and positioning down-beating nystagmus without central nervous system findings |
| |
Authors: | Yasuo Ogawa Mamoru Suzuki Koji Otsuka Shigetaka Shimizu Taro Inagaki Mami Hayashi Akira Hagiwara Naoharu Kitajima |
| |
Institution: | aDepartment of Otorhinolaryngology, Tokyo Medical University, Japan |
| |
Abstract: | We report the clinical features of 4 cases with positional or positioning down-beating nystagmus in a head-hanging or supine position without any obvious central nervous system disorder. The 4 cases had some findings in common. There were no abnormal findings on neurological tests or brain MRI. They did not have gaze nystagmus. Their nystagmus was observed only in a supine or head-hanging position and it was never observed upon returning to a sitting position and never reversed. The nystagmus had no or little torsional component, had latency and tended to decrease with time. The positional DBN (p-DBN) is known to be indicative of a central nervous system disorder. Recently there were some reports that canalithiasis of the anterior semicircular canal (ASC) causes p-DBN and that patients who have p-DBN without obvious CNS dysfunction are dealt with anterior semicircular canal (ASC) benign paroxysmal positional vertigo (BPPV). There are some doubts as to the validity of making a diagnosis of ASC-BPPV in a case of p-DBN without CNS findings. It is hard to determine the cause of p-DBN in these cases. |
| |
Keywords: | BPPV Down-beating Nystagmus ASC Positional nystagmus Positioning nystagmus |
本文献已被 ScienceDirect 等数据库收录! |