Objective: To determine whether Ginkgo biloba extract (ginkgo) improves cognitive function in persons with multiple sclerosis (MS).
Methods: Persons with MS from the Seattle and Portland VA clinics and adjacent communities who scored 1 SD or more below the mean on one of 4 neuropsychological tests (Stroop Test, California Verbal Learning Test II [CVLT-II], Controlled Oral Word Association Test [COWAT], and Paced Auditory Serial Addition Task [PASAT]) were randomly assigned to receive either one 120-mg tablet of ginkgo (EGb-761; Willmar Schwabe GmbH & Co, Germany) or one placebo tablet twice a day for 12 weeks. As the primary outcome, we compared the performance of the 2 groups on the 4 tests at exit after adjusting for baseline performance.
Results: Fifty-nine subjects received placebo and 61 received ginkgo; 1 participant receiving placebo and 3 receiving ginkgo were lost to follow-up. Two serious adverse events (AEs) (myocardial infarction and severe depression) believed to be unrelated to the treatment occurred in the ginkgo group; otherwise, there were no significant differences in AEs. The differences (ginkgo - placebo) at exit in the z scores for the cognitive tests were as follows: PASAT -0.2 (95% confidence interval [CI] -0.5 to 0.1); Stroop Test -0.5 (95% CI -0.9 to -0.1); COWAT 0.0 (95% CI -0.2 to 0.3); and CVLT-II 0.0 (95% CI -0.3 to 0.3); none was statistically significant.
Conclusions: Treatment with ginkgo 120 mg twice a day did not improve cognitive performance in persons with MS.
Classification of evidence: This study provides Class I evidence that treatment with ginkgo 120 mg twice a day for 12 weeks does not improve cognitive performance in people with MS.