[Treatment of senile macular degeneration with Ginkgo biloba extract. A preliminary double-blind drug vs. placebo study]. [Effect of Ginkgo-biloba extract on mental performance. Double-blind study using computerized measurement conditions in patients with cerebral insufficiency]. [Ginkgo extract in impaired vision--treatment with special extract EGb 761 of impaired vision due to dry senile macular degeneration]. [Treatment of cerebral aging disorders with Ginkgo biloba extract. A longitudinal multicenter double-blind drug vs. placebo study]. A double-blind, placebo controlled study of Ginkgo biloba extract ('tanakan') in elderly outpatients with mild to moderate memory impairment. 6-Month double-blind randomised clinical trial of Ginkgo biloba extract versus placebo in two parallel groups in patients suffering from peripheral arterial insufficiency. [The effect of Ginkgo biloba extract in patients with intermittent claudication]. Clinical efficacy of Ginkgo biloba special extract EGb 761 in dementia of the Alzheimer type. A double blind placebo controlled trial of ginkgo biloba extract in acute cerebral ischaemia.
Senile macular degeneration is a frequent cause of blindness for which there is no satisfactory medical treatment. A double-blind trial comparing Ginkgo biloba extract with a placebo was conducted in 10 out-patients at the Hôpital Foch. Drug effectiveness was assessed on the results of fundoscopy and of measurements of visual acuity and visual field. In spite of the small population sample, a statistically significant improvement in long distance visual acuity was observed after treatment with Ginkgo biloba extract. The assumed pathogenesis of senile macular degeneration is discussed with emphasis on free oxygenated radicals. Problem: The effect of ginkgo biloba extract EGb 761 on basic parameters of mental performance. Patients: Seventy-two outpatients with cerebral insufficiency at three test centers. Study design: Double-blind, randomized placebo-controlled study of 24 weeks duration. Test parameters: Psychometric computer-aided examination of the short-term memory and basic learning rate. Results: Statistically significant improvement in the shortterm memory after 6 weeks and of the learning rate after 24 weeks in the test substance group, but not in the placebo group (longitudinal analysis). The difference between the test substance and placebo groups (horizontal analysis) reached statistical significance in the 24th week. Conclusions: Treatment with ginkgo biloba extract EGb 761 improves mental/mnestic performance. The therapeutic efficacy of Ginkgo special extract Egb 761 was investigated in a controlled, double-blind trial involving 99 patients with impaired vision due to senile, dry macular degeneration. The primary objective target variable was the change in the corrected visual acuity of the more severely impaired eye at baseline, during a six months treatment period with either 240 mg/die (group I = 50 patients) or 60 mg/die (group II = 49 patients) Egb 761. Marked improvement of the study participants' vision was observed in both treatment groups already after four weeks, with more pronounced improvements in group I (acuity increases by 0.13 in group I vs. 0.10 in group II after 24 weeks). The fraction of patients with improvement of visual acuity > or = 0.2 was nearly twice as large in the group treated with 240 mg/die Egb 761 as in patients receiving the lower dosage (p = 0.08). Subjective health impairments, if present, could be improved during treatment as well. The investigator rated a favorable tolerability for both dosages of Egb 761. In conclusion, the results demonstrate the therapeutic efficacy of Egb 761 in patients with senile, dry macular degeneration, with obvious benefits in every-day life. The effectiveness of Ginkgo biloba extract in the treatment of cerebral disorders due to ageing was evaluated in a multicentric, double-blind, drug versus placebo trial involving 166 patients. In this study carried out under strict methodological conditions a specially devised geriatric clinical evaluation scale was used. The results confirmed that Ginkgo biloba extract is effective against cerebral disorders due to ageing. The difference between control and treatment groups became significant at 3 months and increased during the following months. These results were concordant with the overall clinical assessment made by the specialist in charge. Thirty-one patients over the age of 50 years and showing a mild to moderate degree of memory impairment entered a 6-month double-blind, placebo controlled, parallel group design study to assess the effects of a standardized Ginkgo biloba extract (containing 24% flavonoid glycosides and 6% terpenes) on cognitive function. Patients were allocated at random to receive oral doses of 40 mg Ginkgo biloba extract or identical placebo 3-times daily. Assessments were made at baseline and after 12 and 24 weeks of treatment using a range of psychometric tests. Efficacy data were available for 27 patients (15 in the placebo group and 12 in the active treatment group). Statistical analysis of the data as compared to baseline suggests that Ginkgo biloba extract had a beneficial effect on cognitive function in this group of patients. Performance on the Digit Copying sub-test of the Kendrick battery was significantly improved at both 12 and 24 weeks, while the median speed of response on a computerized version of a classification task also showed a significant superiority over placebo at 24 weeks. 79 patients suffering from peripheral arteriopathy (Fontaine's stage IIb) completed a 6-month double-blind randomised clinical trial of Ginkgo biloba extract (GBE) (as coated tablets containing 40 mg GBE; rökan) versus placebo in two parallel groups. From the results of measurements of pain-free walking distance, maximum walking distance and plethysmography recordings, GBE was shown to be active and significantly superior to placebo. These results correlated with the physician's and patients' overall assessment of response to treatment. Eighteen patients with stable intermittent claudication were randomized in a double blind cross-over study comparing the effects of the Ginkgo biloba extract GB-8 at a dose of 120 mg o.d. with placebo. All patients were treated for three months with the active extract and three months with placebo. The effects of treatment on arterial insufficiency were quantified by measurements of systemic and peripheral systolic blood pressures, and pain-free and maximal walking distances on a tread-mill. Questionnaires based on visual analogue scales were used to quantify the severity of leg pain, impairment of concentration, and inability to remember. Short-term memory was objectively assessed. We did not find any significant changes in either peripheral blood pressures, walking distances or the severity of leg pain. Systemic blood pressure was reduced both by placebo and GB-8. The impairment of concentration and the inability to remember were both reduced, when comparing results during active treatment to placebo. Short-term memory did not change significantly. In conclusion, our study has shown that treatment with the Ginkgo biloba extract GB-8 improves some cognitive functions in elderly patients with moderate arterial insufficiency, whereas the extract did not change signs and symptoms of vascular disease in the patients. Among the psychiatric illnesses associated with old age primary degenerative dementia of the Alzheimer type (DAT) has gained increasing importance in recent years. Even though a curative treatment of the disease is currently impossible, various drugs can be used to slow down its progression. In the present study the influence of oral treatment with 240 mg/day of Ginkgo bilabo special extract EGb 761 (Tebonin forte, manufactured by Dr Willmar Schwabe, Karlsruhe) on the clinical course of DAT was investigated in a double-blind, randomized, placebo-controlled parallel-group design in 20 outpatients. The duration of treatment was 3 months. The primary outcome variable was the sum score in the SKT-test for the determination of attention and memory. Other psychometric tests (trailmaking test, ADAS, CGI) and electrophysiological investigations (EEG topography) were evaluated descriptively. Although the active-treatment group, with a mean sum score of 19.67 points in the, S.K.T., had a poorer baseline level than the placebo group (18.11 points), it experienced an improvement to 16.78 points under treatment with EGb 761 whereas the placebo group deteriorated to 18.89 points. The differences between the baseline and final values formed the basis for a statistical group comparison, which gave a result favourable to EGb 761, at a significance level of p < .013. In addition to this psychometric confirmation of efficacy, certain descriptive trends were found at the psychopathological (Clinical Global Impression) and dynamic functional (EEG findings) levels, which can be interpreted as evidence of effectiveness of Ginkgo biloba special extract EGb 761 in mild to moderate dementia and of local effects in the central nervous system. Inter-group differences in the ADAS cognitive and non-cognitive subscales did not reach statistical significance, probably because of the small sample size. A double blind placebo controlled trial was conducted in 55 patients of acute ischaemic stroke. Twenty one and twenty six patients were randomly allotted in group A and group B respectively. In group A, the patients received 40 mg Ginkgo biloba extract at 6 hourly intervals along with routine management. The placebo tablets were dispensed in the tablet form of same size, shape and colour and were given in the same way. After the patients were subjected to computerized tomographic (CT) scan to confirm acute ischaemic infarction, they were assessed on Mathew's scale and reassessed, at 2 weeks and 4 weeks of drug/placebo administration. Both groups showed significant improvement in Mathew's scale score after 2 weeks and 4 weeks. The difference in degree of change was negligible (p > 0.05) in either group. Estimation of relative changes of neurological deficit based on baseline values also showed negligible (p > 0.05) difference. A trial of Ginkgo biloba extract within 6 hours of stroke in a larger dose and in larger sample could be beneficial clinically in patients of cerebral ischaemic infarct, and needs further study. The usefulness of the plant extract has been demonstrated clinically and experimentally in more than 40 trials of chronic cerebral ischaemia, done elsewhere. This was not evident in our study as our study group was different (more than 48 hours after stroke). There appears to be no contraindication or adverse effect of this medication (Ginkgo biloba) in acute ischaemic stroke.
The question as to whether people with AMD should take Ginkgo biloba extract to prevent progression of the disease has not been answered by research to date. Two small trials have suggested possible benefit of Gingko biloba on vision and further trials are warranted. Ginkgo biloba is widely used in China, Germany, and France. Future trials should be larger, and last longer, in order to provide a more robust measure of the effect of Gingko biloba extract on AMD.