Objectives: The aim of the study was to evaluate the sleep architecture and its possible alterations in chronic tinnitus patients, and investigate any possible correlation between sleep architecture modifications and tinnitus perception, adaptation, and the degree of discomfort in these patients.
Design: In a prospective, case-control, nonrandomized study, 18 patients affected by chronic tinnitus were compared with a homogeneous control group consisting of 15 healthy subjects. The experimental group was enrolled at the Tinnitus ambulatory at Policlinico Umberto I Department of Sensory Organs, and the control group was composed of voluntary subjects. A full overnight polysomnography was performed on both groups. Tinnitus patients answered two questionnaires: the tinnitus handicap inventory (THI) and a questionnaire concerning their subjective sleep quality, tinnitus intensity before bedtime, tinnitus intensity at remembered nocturnal wake-up periods, and tinnitus intensity at morning wake-up. Controls completed only the sleep quality questionnaire.
Results: All tinnitus patients had a statistically significant alteration in sleep stages. Average percentage of stage 1 + stage 2 was 85.4% ± 6.3, whereas, in the control group, the average percentage of stage 1 + stage 2 was 54.9 ± 11.2 (p < 0.001). Stages 3 and 4 and rapid eye movement (REM) sleep was lacking in all tinnitus patients with an average percentage of 6.4 ± 4.9 of REM sleep, and 6.4 ± 4.9 of stages 3 + 4. The control group showed an average percentage of 21.5 ± 3.6 of REM sleep and 21.5 ± 3.6 of stages 3 + 4 (p < 0.001). No correlation was found between the decrease of REM and the increase of the THI score in the tinnitus group (r = 0.04). However, a mild correlation was found between the increase of light sleep (stage 1 + stage 2) and the THI score reported by the tinnitus group. Therefore, patients with light sleep report a higher THI score (r = 0.4).
Conclusions: The significant alteration of sleep parameters assessed in tinnitus patients underlines the necessity to consider an adequate therapy that could improve patients' sleep quality and also opens avenues for further investigations.