No Strong Clinical Association Between Chronic Pain and Tinnitus

Similarities exist between chronic tinnitus and chronic pain. Both are subjective sensations initially produced by the similar physiological processes. Patients of each condition often suffer from hypochondriasis, obsessive-compulsive behaviors, increased tendency to self-focus, perceived lack of control over symptoms and life events, maladaptive coping strategies and others. Both groups are caught in a vicious circle whereby their symptoms lead to increased depression, fatigue and anxiety, which, in turn, exacerbate their symptoms. Both disorders are difficult to treat, requiring individual treatment plans. Once first line therapies for each disorder are exhausted, patients may be offered antidepressants, biofeedback, electrical stimulation, or acupuncture.

Similarities in neuro-biological models, patient psychological profiles, and treatment options warrant greater attention. A team of researchers set out to examine these similarities. Their objective was to find out how many chronic pain patients suffer from tinnitus, the relation of tinnitus to pain in onset or severity, and whether treatments received for chronic pain impact tinnitus.

The authors of "Clinical Associations Between Tinnitus and Chronic Pain," are Jon E Isaacson MD, Matthew T Moyer MD, H Gregg Schuler, Clinical Nurse Specialist, and George F Blackall Psy. D, MBA, Assistant Professor, all from the Pennsylvania State University Milton S. Hershey Medical Center, Hershey, PA. Their findings are to be presented at the American Academy of Otolaryngology--Head and Neck Surgery Foundation Annual Meeting and OTO EXPO, September 22-25, 2002, at the San Diego Convention Center, San Diego, CA.

Methodology: A survey was administered to new patients at a tertiary care pain clinic over a six-month period. All participants completed questions regarding demographic profiles and hearing health. Those respondents confirming tinnitus were asked to qualify tinnitus, identify tinnitus risk factors, identify associations between tinnitus and pain, and then complete the Tinnitus Handicap Inventory (THI), which objectively quantifies the severity of the tinnitus and its impact on quality of life. The data was then analyzed.

Results: Seventy-two patients (50 males, 22 females) completed the survey. The average age was 53 for females (range 16 to 88), 47.5 years for males (range 24 to 81). Duration of pain was most commonly recorded as greater than five years (16/39, 41 percent). The distribution of pain sites was roughly equivalent between males and females.

Thirty-nine (54.2 percent) reported having tinnitus, 29 females and 10 males. The average age was 52.8 years for females (range 16 to 88) and 44.3 years for males (range 24 to 67). Duration of pain in this group was again most commonly recorded as between six months and five years. The back was the most frequently reported primary site of pain.

Other findings for those reporting tinnitus include (variance in the sample size reflects that some questions were not answered):

* The average pitch of tinnitus was graded as 6.1 on a ten-point scale where a lower score indicates a lower pitch. The average volume of tinnitus was graded as a 4.9 on a ten-point scale where a lower score indicates a lower volume.

* Eighteen subjects reported a previous subjective hearing loss (48.7 percent); 15 subjects reported a previous history of noise exposure ( 41.7 percent). Only four subjects had a history of previous head injury. Coffee consumption varied, with 26 subjects confirming they drank caffeinated beverages daily with a range of one to eight cups (and one subject admitting to 31 cups of coffee per day).

* The average duration of tinnitus was 13 years. Fifteen subjects reported the onset of tinnitus prior to the onset of pain; 13 subjects reported the onset of tinnitus after pain occurred; and three reported that the two began concurrently. Four subjects reported an association between tinnitus and pain; eight subjects reported that a specific pain treatment improved their tinnitus.

* The mean THI score was 27 out of a possible 100 (N=35, range 0 to 96), indicating only a mild handicap for the group as a whole. No handicap (score of zero to 16) was demonstrated in 15 (42.9 percent), mild handicap (score of 18-36) in nine (25.7 percent), moderate handicap (score of 38 to 56) in seven (20 percent), and severe handicap (score of >58) in four (11.4 percent). An analysis of variance (ANOVA) failed to find any significant relationship between handicap from tinnitus and duration of pain, site of pain, or duration of tinnitus.

Conclusions: This study set out to examine a chronic pain population where 53.9 percent reported tinnitus (as compared to the national average of 16 to 35 percent in the general population). While the tinnitus did not appear to be a major problem for these patients, it seems unusual that such a high percentage of them have tinnitus. The researchers believe that this warrants continued research between these two entities. The high prevalence may be due to the psychological overlap between groups of patients suffering from tinnitus and pain. While the average duration of tinnitus appeared long (13 years), the number of subjects reporting the pain began before the tinnitus was roughly the same as those reporting the pain began after the tinnitus. Only four subjects felt that their tinnitus was related in any way to their pain, and only eight subjects reported that their tinnitus improved when their pain was successfully treated.

Tinnitus did not appear to be a handicap for this study group. Only four subjects scored in the severe handicap range with the majority of subjects (24) scoring in the mild to no handicap range. No significant relationship was found between tinnitus handicap and duration of pain, site of pain, or duration of tinnitus. The researchers speculate that tinnitus might not be a significant problem in their group because the patients are so focused on their pain issues, that all other symptoms become secondary. There was no score for intensity or handicap from pain, nor an instrument to measure depression.

This original study finds that the disorder is not directly related to the specific complaint of pain, and may not change despite successful pain management. Tinnitus was not perceived as a significant handicap in our sample of patients experiencing chronic pain.

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