Auditory evoked brainstem responses in patients with cronic hypozincemia: a clinical study.
Abstract
Some authors have postulate that sistemic zinc can be employed in the threatment of tinnitus, because a sub-clinical hypozincemia is suposed to promote this auditory disturbance. However, in the majority of the cases of tinnitus, this hypozincemia was not confirmed. There is not enough randomized studies that could show the relationship between zinc and tinnitus.
The main goals of this study were to evaluate a group of patients who have cronic hypozincemia, due to an extensive ressection of the small bowel, by means of the Auditory Evoked Responses, and to compare them with a control group, without auditory disorders, and with a group of patients who have tinnitus, without vertigo or hearing loss, in order to evaluate the functional features of the auditory pathways.
The patients were submitted to a detailled clinical observation, seric examination for zinc, magnesium, glucosis and tireoidean hormonies, audiometry, imitanciometry, speech discrimination tests and brainstem auditory evoked responses. The results of the three groups were statistically compared.
There were significative differences between the group with hypozincemia and the control group, concerning with the accoustic reflex for 1000 and 2000 Hz, and for the intervals III-V and I-V and for the amplitude of wave V, in the auditory evoked responses. There were no statistically significative differences between the groups with hypozincemia and with tinnitus, concerning with the auditory function.
We concluded that the nutritional disturbance of the patients with short small bowel, which includes hypozincemia, colaborates for the presence of a functional alteration in the central auditory system, and that this alteration makes this group of patients eletrophysiologically similar with those who have cronic tinnitus.
