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- Ginkgo (Ginkgo biloba)
- Neuropsychiatric Symptoms
- Mild Cognitive Impairment
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Date:
05-30-2014 | HC# 051451-497
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Re: Ginkgo Extract Found Safe and Effective in Treating Amnestic Mild Cognitive Impairment in Exploratory Trial
Gavrilova
SI, Preuss UW, Wong JWM, et al. Efficacy and safety of Ginkgo biloba extract EGb 761® in mild cognitive
impairment with neuropsychiatric symptoms: a randomized, placebo-controlled,
double-blind, multi-center trial. Int J
Geriatr Psychiatry. March 16, 2014; [epub ahead of print]. doi:
10.1002/gps.4103.
Mild
cognitive impairment (MCI) is a condition associated with an elevated risk of
developing dementia; however, it is not necessarily a transitional stage of
dementia. MCI is often accompanied by neuropsychiatric symptoms, which are an
indicator of an increased risk for dementia. An indicator of a high risk for
dementia is amnestic MCI (aMCI), which is characterized by impaired short-term
memory as the main symptom. Many studies demonstrate the efficacy of ginkgo (Ginkgo biloba) extract EGb 761®
(Dr. Willmar Schwabe GmbH; Karlsruhe, Germany) in improving cognition and
neuropsychiatric symptoms associated with dementia. The purpose of this
randomized, placebo-controlled, double-blind, multicenter trial was to evaluate
EGb 761 in patients with aMCI and at least one type of neuropsychiatric
symptoms.
Patients
(n = 160, aged ≥ 55 years) diagnosed with aMCI according to international
consensus criteria were enrolled at psychiatric or neurologic outpatient
departments of 7 academic hospitals in Russia. Inclusion criteria (in part
according to the international consensus criteria) were as follows: cognitive
complaints expressed by the patient were corroborated by an informant; the
total score on the revised version of the cognitive part of the Cambridge
Mental Disorders of the Elderly Examination (CAMCOG) was below the 10th
percentile for age, sex, and educational level; the CAMCOG combined memory
score was ≤ 20 for patients < 80 years old and ≤ 17 for patients ≥ 80 years
old; a decline from a former level of functioning was demonstrated either by
informant report or by cognitive testing; basic activities of daily living were
preserved with a mean score < 4 on the short form of the Informant
Questionnaire on Cognitive Decline in the Elderly; overall cognition was not
severely impaired as evidenced by a score of ≥ 24 on the mini-mental state
examination; Diagnostic and Statistical
Manual of Mental Disorders, 4th Edition (DSM-IV) criteria for dementia were
not fulfilled; cognitive complaints were present for ≥ 6 months; a total score
of ≥ 6 on the 12-item Neuropsychiatric Inventory (NPI); on the NPI, at least 1
of the item scores for "depression/dysphoria," "anxiety," "apathy/indifference,"
"agitation," or "irritability/lability" were ≥ 4; a
magnetic resonance imaging (MRI) scan taken ≤ 1 year prior to screening had to
be consistent with the diagnosis of MCI; major depression was ruled out; and
adequate Russian language skills were required. Also, an informant who was
frequently in contact with the patient was required to provide information
about the patient's history of cognitive problems, functional abilities, and
behavioral symptoms.
The
exclusion criteria were as follows: any type of neurological disorder, stroke
with sequelae within the last 3 months, hemorrhagic stroke within the last 12
months before enrollment, or dementia; current or recurrent psychiatric
disorder; severe or insufficiently controlled cardiovascular disorder or
insulin-dependent diabetes mellitus; severe hepatic or renal dysfunction,
clinically significant anemia, thyroid dysfunction, or vitamin deficiency;
gastrointestinal disorders with uncertain absorption; alcohol or substance
abuse; active malignant disease; severe and insufficiently corrected impairment
in vision or hearing; previous participation in any trial of a ginkgo product;
female patients of child-bearing age and no contraception; or intake of any
medication that could interfere with the efficacy assessment.
Patients
received either 240 mg/day EGb 761 or placebo for 24 weeks. The following
battery of cognitive tests was conducted at baseline, week 12, and week 24: NPI,
Geriatric Depression Scale (GDS), the state subscale of the State-Trait Anxiety
Inventory (STAI-X1), the Clinical Global Impression (CGI), the Trail-Making
Test (TMT), and CAMCOG. In general, both groups of patients improved; however,
patients in the EGb 761 group had a greater improvement. On the NPI composite
score, the EGb 761 group had a statistically significantly greater improvement
than the placebo group (P = 0.001). Also, according to the NPI composite score,
statistically more patients in the EGb 761 group had a clinically significant
improvement than in the placebo group (78.8% vs. 55.7%, respectively; P =
0.002). Similarly, the EGb 761 group was significantly more improved than the
placebo group on the STAI-X1 (P = 0.027), the informants' global impression of
change (P = 0.014), and both TMT scores (P = 0.045 and P = 0.011). Symptoms of
depression on GDS total score were not significantly altered by EGb 761, though
there was a trend (P = 0.066); the authors attribute this to the low baseline
depression scores (i.e., the patients were close to "normal"). Adverse
events (AEs) were reported by 37 patients taking EGb 761 and 36 patients
receiving placebo, and all were non-serious. Eighteen AEs in the EGb 761 group
and 16 in the placebo group had a potential causal relationship with treatment
(the specific AEs were not noted), though none were serious. AEs reported
included headache, increased blood pressure, respiratory infections, and
gastric discomfort.
According
to the authors, this is the first study of EGb 761 in patients with aMCI
diagnosed according to the international consensus criteria. The authors point
out that the conclusions may not apply to aMCI diagnosed by other criteria since
there is dissimilarity among the different MCI diagnostic criteria. The authors
conclude that EGb 761 treatment improved performance in cognitive tests,
tapping attention, working memory, visuospatial orientation, and executive
function. Patients with MCI do not have significant impairment at work or in
social life, so it is difficult to gauge the relevance of the observed
improvements. However, low executive function is associated with a shorter time
to progression to dementia and Alzheimer's disease. There is the potential that
EGb 761 would delay the progression. Also, the improvement in TMTs may indicate
a better ability to deal with demands at work. The conclusions of this study
are supported by the excellent methodological design.
—Heather S. Oliff,
PhD
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