抄録
Bilateral vestibular failure causes movement-dependent postural vertigo, unsteadiness of gait, and in serious cases patients complain of blurred vision while walking (known as the jumbling phenomenon). This condition is defined as bilateral vestibulopathy and its diagnostic criteria have been cited in various professional publications. These criteria include, symptoms, bedside evaluation (e.g., Head Impulse Test), laboratory tests (e.g., caloric tests) and other causes excluded. On the other hand, in Japan, the Peripheral Vestibular Disorder Research Committee has proposed a set of diagnostic criteria for bilateral vestibular losses, which is based solely on the result of an ice-water caloric test, regardless of whether the patient has the characteristic symptoms or not.
The purpose of this retrospective study was to clarify the relationship between the vestibular failure tested by both the caloric test and video Head Impulse Test (vHIT), and the presence of symptoms characteristic of bilateral vestibulopathy.
A total of 210 patients were screened during the study period. Eight patients were included in this study who showed bilateral absent caloric responses to the ice-water caloric test due to peripheral vertigo. Among these 8 patients, only 3 patients complained of the jumbling phenomenon and vHIT showed a bilateral profound vestibular deficit. vHIT did not show any bilateral profound vestibular deficit in the other 5 patients. These results show that the abnormal caloric responses may not have clinical significance in some cases. The authors believe that bilateral vestibulopathy should be considered first with patients who have characteristic symptoms. Furthermore, they should be tested by a combination of 2 test batteries (the ice-water caloric test and vHIT) to make a proper diagnosis.
