A Cochrane review included 4 trials with a total of 1543 participants. Three trials (n=1143) included patients with a primary complaint of tinnitus and one (n=400) included patients with mild to moderate dementia, some of whom had tinnitus. The duration of treatment was 6 to 12 weeks. There was no evidence that Gingko biloba was effective in patients with a primary complaint of tinnitus. In the study of patients with dementia, mean baseline levels of tinnitus were low (1.7 to 2.5 on a 10-point subjective symptom rating scale). A small but statistically significant reduction of 1.5 and 0.7 points was seen in patients taking Gingko biloba with vascular dementia and Alzheimer's disease respectively (p<0.01; 1 trial, n=400). The practical clinical significance of this is unclear. The incidence of side effects was low.
Comment: The quality of evidence is downgraded by indirectness (differences in patients, a remarkable number of dementia patients were included).
A systematic review including 23 studies with a total of 2 064 subjects was abstracted in DARE. Ginkgo biloba (5 RCTs, n=1 403): 3 trials showed significant reduction in tinnitus intensity compared with placebo and 2 trials showed no significant difference between treatments. Acupuncture (5 RCTs, n=121): 3 RCTs showed no significant difference to placebo. 1 trial found subjective improvement in a higher proportion of patients receiving acupuncture (5 out of 14) compared with placebo (0 out of 14), but no difference in objective measures of tinnitus. 1 trial found significant short-term improvement in tinnitus intensity with acupuncture but no statistically significant difference between treatments at 6 months. No significant difference compared to placebo was found for low-power laser treatment (3 RCTs, n=126), homeopathy (1 RCT, n=28), electromagnetic therapy (4 RCTs, n=156), ear-canal magnets (1 RCT, n=50) or hypnotherapy (2 RCTs, n=100). However, hypnotherapy increased relaxation in one RCT (in 5 out of 14 patients) and improved the sense of well-being in the other RCT (in 20 out of 44 patients given hypnotherapy versus 6 out of 42 given placebo), but the trial was methodologically flawed. One RCT showed electromagnetic therapy significantly improved a tinnitus symptom score (45% improved versus 9% with placebo).
Comment: The quality of evidence is downgraded by inconsistency (heterogeneity in patients and treatments).