Morgenstern, 1997, [75] [article in German]

Non-auditory tinnitus

Prospective, double-blind, randomized, placebo- controlled

99 with tinnitus (49 in the treatment group and 50 in the placebo group)

>18 years (no upper limit)

3 × 40 mg = 120 mg EGb 761/day (vs. placebo) for 12 weeks, no follow-up

Audiometrically detectable change in tinnitus sound intensity on the ear that is initially severely affected. Accompanying variables: tinnitus-volume in the contralateral ear, reproducibility click-evoked OAE and their response, tinnitus intensity, hearing loss and subjective patient impression.

From the eighth week of treatment onwards, there was a significant decrease in the average noise level in the GBE treatment group. The observed improvements were within a range of 5 to 10 decibels (dB), which is considered clinically relevant; the values in the placebo group remained unchanged.

Morgenstern and Biermann, 2002, [72]

Non-auditory tinnitus

Double-blind, randomized, placebo- controlled, monocentric

52 with tinnitus

median age: 45 years in the GBE treatment group and 47 years in the placebo group

2 x 80 mg = 160 mg EGb 761/ day (vs. placebo) for 12 weeks, no information on follow-up

Primary outcome: difference in tinnitus volume between day 10 of an in-patient phase and months 3, 2 and 1 of an out-patient phase, i.e., change in tinnitus volume in the more severely affected ear; Secondary outcomes: click-evoked OTE, tone threshold audiometry, speech audiometry, 6-point rating scale of subjective tinnitus intensity.

Statistically significant superiority of GBE over placebo in the reduction of the loudness of subjective ear sounds (tinnitus) already evident after 4 weeks and persisted until the end of the study at 12 weeks (p = 0.039).

Polanski, 2016, [78]

Tinnitus associated with SSHL

Prospective, randomized, double-blinded, placebo- controlled

53 with tinnitus (12 GBE treatment group, 13 placebo, 13 α-lipoic acid plus vitamin C, 15 papaverine hydrochloride plus vitamin E

Mean age 72.6 years

120 mg EGb 761/ day (vs. α-lipoic acid [60 mg/day] plus vitamin C [600 mg/day], papaverine hydrochloride [100 mg/day] plus vitamin E [400 mg/day], and placebo [starch capsules] for 24 weeks, no information on follow-up

Change from baseline in THI.

No statistically significant difference between THI by degree (p = 0.441) and by score (p = 0.848) before and after treatment for any of the treatment arms.

Procházková, 2018, [73]

Unilateral or bilateral chronic or subchronic tinnitus

Randomized, double-blind, reference- controlled single-center

200 with tinnitus (100 received GBE treatment and 100 received pentoxifylline)

Mean age = 55.4 ± 10.5 years for GBE treatment group and 53.1 ± 10.9 years for pentoxifylline

120 mg EGb 761/ day (vs. 600 mg pentoxifylline/ day) for 12 weeks, no follow-up

Change in two 11-Point Box Scales for tinnitus loudness and annoyance by tinnitus from baseline.

Significant improvements were observed in the 11-Point Box Scales for tinnitus loudness and annoyance, but there was no relevant difference between the two treatment groups (p = 0.93 and 0.94, respectively).