Chinese herbal medicine for patients with mild to moderate Alzheimer disease based on syndrome differentiation: a randomized controlled trial

Alzheimer disease (AD) is a chronic neurodegenerative disease that is characterized by its gradual progression. At present, the cause and mechanism of AD are yet unclear, and there is no effective therapy for treating it. With development of global aging, the prevalence rate of AD is increasing. The life quality of elderly people is affected severely by AD that is ultimately life-threatening. Recently, study on treating AD with traditional Chinese medicine (TCM) has deepened.To explore the therapeutic effects of a syndrome differentiation-based TCM regime in treating patients with mild to moderate AD for improving cognition, and to evaluate the changes in brain function of AD patients observed by resting-state functional magnetic resonance imaging (fMRI) technique.Adopting the internationally recognized criteria developed by National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer's Disease and Related Disorders Association, the clinical trial was conducted on 131 patients with mild to moderate AD from 5 communities and 7 social welfare institutions. Participants were accepted after informed consent was received, and laboratory tests and a head imaging study were conducted. The patients were randomly divided into Chinese medicine group (CMG) (66 cases) or Western medicine group (WMG) (65 cases). Patients in the CMG were treated monthly with Chinese medicine according to syndrome differentiation. Patients in the WMG were treated with donepezil at a dose of 5 mg once daily. The therapeutic course lasted 48 weeks.The scores of Mini-Mental State Examination (MMSE), Fuld Object-Memory Evaluation (FOM), Block Design (BD) and Digit Span (DS) were used to evaluate the cognitive function; resting-state fMRI was used for observing brain function. The questionnaires and fMRI were performed before and after treatments.The cognitive functions of the patients in the CMG and WMG were improved after treatment. MMSE score was improved significantly in both groups (P<0.05 or P<0.001). After 48 weeks of treatment, 70.91% patients in the CMG had an improved MMSE score and 20% got worse, however, 55.77% patients in the WMG were improved in MMSE score and 34.62% got worse. Scores of FOM denominator and BD increased significantly in both groups; scores of FOM numerator and DS were also increased in the CMG (P<0.05 or P<0.01). The results of fMRI suggested that both Chinese medicine and donepezil treatment improved the connectivity between posterior cingulated gyrus and specific areas in the brain. The influence range of Chinese medicine primarily impacted on the left parietal lobe, being less than the influence range of donepezil, which primarily affected both sides of frontal lobes.TCM treatment based on syndrome differentiation is effective in improving cognitive function of patients with mild to moderate AD and increasing the brain function by increasing connectivity between posterior cingulated gyrus and specific areas in the brain.