Vascular dementia is one of the most common dementias ranked after Alzheimer's disease. It's a growing problem in China, with a prevalence of about one to three percent, similar to prevalence rates in the United States and Europe. Because some medications for the condition are very expensive for most patients in China, researchers focused on finding treatments that would be effective and less costly. Chinese herbal medicines not only are less expensive and have fewer side effects than standard chemical medications, but they are also more accepted by the Chinese people, according to lead researcher Jinzhou Tian, M.D., Ph.D., director of the Institute of Geriatrics, Beijing University of Chinese Medicine.
For this study, researchers selected the gastrodine compound granule. It's extracted from tall gastrodia tuber plants and six other herbs and is the first of new herbal drugs in dementia to be tested in clinical trials. The 12-week, randomized, double-blind trial was done in Beijing Dongzhimen Hospital, one of the hospitals running the clinical trials between 1999 and 2002. Researchers identified 120 stroke patients (75 male 45 female) who were diagnosed with mild to moderate VaD lasting three months or more. All patients were assessed for VaD at baseline and randomly divided into two treatment groups. One group (70 patients) was given one bag of the gastrodine compound granule (2.6 milligram gastrodine) three times a day for 12 weeks. The second group (50 patients) was given 40 mg of Duxilâ (almitrine + raubasine) three times a day for 12 weeks. This is a drug used to treat stroke patients in China. Both the gastrodine compound granule and the Duxilâ granule were dissolved in hot water and given orally.
In the gastrodine group, there were significant increases of the average MMSE (mini-mental state exam) score compared to baseline scores (20.83 vs.18.96). In the areas of memory, orientation, calculation, and language, the MMSE showed similar improvement in both groups.
However, the gastrodine group showed a significant difference in the Blessed Behavioral Scale (BBS) score - including behavior, activities of daily living, and personality - between endpoint (15.72) and baseline (18.76), as well as at endpoint (17.08) in the Duxilâ group. A score greater than or equal to 16 is abnormal and a score less than 16 is normal. The gastrodine group also suffered fewer side effects. Researchers say combined results showed the gastrodine group improvement was 51.43 percent, with 16 of the 70 cases showing much improvement, 20 cases with some improvement, and 34 cases with no change. The improvement rate for patients treated with Duxilâ was 52 percent, with seven of the 50 cases showing much improvement, 19 cases with some improvement, and 24 cases with no change.
The study also found that the gastrodine treatment may increase regional cerebral blood flow in VaD patients, but Tian says further study is needed to determine other benefits. Researchers also say a study of six months or more is needed to further determine the clinical effectiveness of the gastrodine compound granule for treating mild to moderate VaD. Given the positive results in the areas of memory and behavior, they say further research into herbal therapies for VaD may also be warranted.
"Chemical drugs, such as cholinesterase inhibitors, are effective in the treatment of cognitive and memory function in dementia, but these drugs are expensive and have side effects," says Tian. "This study might result in doctors considering the use of herbal medications, such as gastrodine compound granules to supplement the treatment of mild and moderate cognitive impairment in primary care for the elderly with cerebral ischemic damage."
Co-authors are Aihua Zhu, Jing Shi, Junxiang Yin, Jian Zhong, Chengzhi Yang, Shuliang Peng, Xianfeng Liu and Yongyan Wang.