Test May Help Clarify Tinnitus Status in Normal Listeners
Auditory brainstem response results could be useful for evaluating people with normal hearing and tinnitus
WEDNESDAY, June 18 (HealthDay News) -- People with normal hearing and tinnitus performed slightly differently than normal listeners without tinnitus on an auditory brainstem response test, indicating the test may be useful in evaluating these patients and providing possible evidence of subtle hearing loss, according to a report in the June issue of the Archives of Otolarynology -- Head & Neck Surgery.
Helga M. Kehrle, M.D., of the Hospital de Base de Brasilia, and colleagues evaluated 37 normal-hearing patients with tinnitus (61 ears because 13 of these patients had unilateral tinnitus) and 38 normal-hearing patients without tinnitus (76 ears). They compared the groups based on eight criteria: waves I, III and V; the interpeak intervals I-III, III-V and I-V; the interaural latency difference (wave V); and the V/I amplitude ratio.
Some 43 percent of the 37 normal-hearing tinnitus patients had abnormal results in at least one of the eight parameters, including a significant prolongation of the latencies of waves I, III and V compared with the control group, the researchers found. Specifically, interpeak III-V value was significantly larger in the study group versus the control group, and, while the V/I amplitude ratio was within normal limits in both groups, it differed significantly in the tinnitus group compared with the non-tinnitus patients.
"Although the averages obtained in several analyzed parameters were within normal limits, the auditory brainstem response results from the patients with and without tinnitus and normal hearing are different, suggesting that auditory brainstem response might contribute to the work-up of these patients," the authors write. "Our data show that there are changes in the central pathways in the study group. The meaning of these changes must be further investigated."