Phytomedicine, Vol. 5(6), pp. 41 7- 424
© Gustav Fischer Verlag 1998 _
Clinical efficacy of Ginkgo biloba special extract
EGb 761 in dementia of the Alzheimer type*
K. Maur er' , R. IhF , T. Dierks! and L. Frolich!
'Klinik fur Psychiatr ie I, Zentrum der Psychiatr ie, Klinikum der Johann-Wolfgang-Goethe-Universitiit, Frank furt, Germany;
2Psychiatrische Klinik, Rheinische Landes- und Hochschulklinik, Dusseldorf, Germany
Summary
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 biloba special extract EGb 761 (Teb-
onin" forte, manufactured by Dr. Willmar Schwabe, Karlsruhe) on the clinical course of DAT was inves-
tigated 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 ac-
tive-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 favour-
able to EGb 761, at a significance level of p < .013. In addition to this psychometric confirmation of ef
ficacy, 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 Gink
go biloba special extract EGb 761 in mild to moderate dementia and of local effects in the central ner-
vous system. Inter-group differences in the ADAS cognitive and non-cognitive subscales did not reach
statistical significance, probably because of the small sample size.
Key words: Gingko bi/oba, double-blind, randomized placebo controlled study, dementia of the Alzhei-
mer type
Introduction
The gradual inversion of the age pyramid in Western
industrialized countries means that the number of geri-
atric diseases is steadily increasing. In their daily prac-
tice doctors are confronted not only with cardiovascu-
lar diseases, but also with the problem of dementia syn-
dromes. A substantial proportion of these patients ex-
hibit senile dementia s of various degrees of severity,
among which primary degenerative dementia of the
* Reprinted from J. psychiat. Res., Vol. 31, No .6 , pp.
645-655, 1997, with permission from Elsevier Science.
Alzheimer type (DAT) occupies the most importa nt po-
sition from both a qualitative and quantitative point of
VIew.
Because of the unclear aetiology and the progressive
nature of DAT, the only therapeutic options are to
maintain mental performance and slow down further
progress of the condition. Although biochemical dis-
turbances in the neurotransmitter systems and in the
glucose metabolism have been detected experimentally
and clinically in Alzheimer patients, drug treatment at
this level has so far met with very limited success. Both