The International Tinnitus Journal

Association between Anterior Cervical Osteophytes And Parasympathetic Dysfunction In Tinnitus Patients

Background Tinnitus is a conscious perception of an auditory sensation in the absence of a corresponding external stimulus. Tinnitus can have a strong impact on the quality of life. The cause of tinnitus is not exactly known. Objectives To assess the reliability of portable infrared pupillometry. To study the hypothesis that enlarged anterior osteophytes of cervical vertebras influences the parasympathetic nervous system. Methods Nineteen tinnitus patients were examined with a portable infrared pupillometer and had X-ray examination of the cervical spine. The control patient population included 79 patients who visited the pain clinic for non-tinnitus complaints. Five different pupillometry values were estimated. The intraclass correlation coefficient was used to measure the inter-observer reliability. A multiple linear regression model was used to examine the association between the size of anterior osteophytes of cervical vertebras and pupillometry measurements. Results Inter-observer reliability was excellent for baseline pupil diameter and maximum constriction amplitude (values>= 0.75), moderate to good for pupillary constriction rate and maximum constriction velocity (values 0.41 - 0.74) and poor for latency constriction. Baseline pupil diameter, maximum constriction amplitude and maximum constriction velocity were significant lower in tinnitus patients. Multiple linear regression showed a significant effect of the size of anterior osteophyte of the sixth and third cervical vertebra and the intervertebral disc space between the third and fourth cervical vertebra on maximum constriction amplitude of the pupillometry measurement. In tinnitus patients a significant effect was found of hearing loss of 8 kHz on maximum constriction amplitude. Conclusion Inter-observer reliability was excellent for pupil diameter and maximum constriction amplitude (values>= 0.75) measured with a pupillometer. Pupil diameter, maximum constriction amplitude and maximum constriction velocity were significant lower in tinnitus patients. These results indicate that the parasympathetic nervous system is impaired. Large anterior osteophytes on the sixth and third cervical vertebra had a significant effect on maximum constriction amplitude, which we interpreted as an effect on the autonomous nervous system by activating the glossopharyngeal and vagal nerves. Pupillometry is valuable diagnostic measurement for tinnitus patients.