[Comparative study on the clinical features of Alzheimer's disease and vascular dementia].

OBJECTIVE: To investigate the clinical features of Alzheimer's disease (AD) and vascular dementia (VaD), and to find effective methods for differential diagnosis between the two entities. METHODS: Totally 112 AD patients and 92 VaD patients were enrolled in this study, consisted of patients from the memory clinics and patients from the community population visited during the epidemiological survey from 1996 to 2000. Diagnosis of dementia, probable AD and probable VaD were made according to international criteria. Results of specific neuroimaging examination were referred to verify the diagnosis and the final diagnosis of each patient was determined from the discussion between clinical experts and radiological professionals. Analysis on clinical and neuroimaging data was performed, aiming at finding differential points between the two dementia-subtypes. A logistic binary multiple regression analysis was performed to pick out those statistically significant clinical features for differential diagnosis at last. RESULTS: AD and VaD patients have different clinical features in various demented stages, therefore the indexes that differentiate the two dementia subtypes change accordingly. The predominant features of mild AD appear to be deficits of prolonged memory and learning ability, while the major impairment of mild VaD patients is decline of calculating ability. With the progress of dementia, learning ability and attention turn to be the effective indexes for differential diagnosis. In the mild and moderate demented stage, AD patients are inferior to VaD patients in handling finacial affairs and making phone calls, while VaD patients often degenerate in daily activities concerning with both physical ability and intellectual level. Severe VaD patients appears more global degeneration of living ability compared to AD patients. The difference of ADL scores between the two subtypes is significant in moderate to severe demented patients (P < 0.05). Psychological behavior symptoms, such as repeatedly collecting useless things, are the characteristic manifestation to differentiate AD from VaD in all clinical stages. CONCLUSIONS: The results of our study indicate that substantial differences exist between AD and VaD patients. Such differences can be attributed to the differences of lesion nature and distribution, as well as the underlying pathophysiological procedures of each disease.

Prevalence of Parkinson's disease and related disorders in the elderly population of greater Beijing, China.

A lower prevalence of Parkinson's disease (PD) has been reported for Chinese populations, but it is unclear whether this observation reflects a lower disease risk or is an artifact of case finding. We ascertained the prevalence of PD in elderly residents of an area that was a composite of 27 urban and rural communities of Greater Beijing, China. A team of university neurologists went door-to-door throughout the study area, examining 5,743 residents (at age 55 years or older) and made preliminary determinations of which residents had PD or other types of parkinsonism. Final determinations were made after follow-up and reevaluation of those persons who were either deemed to have parkinsonism or were suspected of having the condition (n = 144; median follow-up = 40 months). Based on stringent diagnostic criteria, 110 persons were identified to have parkinsonism, of whom 64 (58%) had PD. The prevalence of PD increased with advancing age and was about 1% overall and for each gender. In rural communities, 22 persons had PD, but 20 persons (91%) were first diagnosed for this condition by the study neurologists. The prevalence figures obtained in this study are similar to some of the highest prevalence figures reported in the West.

[Evaluation on the disability weight of Alzheimer's disease and Parkinson's disease in Beijing].

OBJECTIVE: To formulate the classification criteria of disability weight for Alzheimer's disease (AD) and Parkinson's disease (PD) in China and to evaluate the disability weight of AD and PD in population over 60 years old in Beijing. METHODS: Based on the criteria of Global Burden of Disease (GBD), a seven-grade disability classification was used to develop a new disability classification criteria for AD and PD in terms of Delphi method in China. Using the data from epidemiological survey for AD and PD in Beijing in 1997 and new criteria, mean disability weights of AD and PD in population over 60 years old in Beijing were obtained. RESULTS: The mean disability weights of Alzheimer's disease was 0.40 in population over 60 years old who received treatment in Beijing and 0.52 in those without treatment while the mean disability weights of Parkinson's disease were 0.30 in the patient receiving treatment and 0.23 in those without treatment. CONCLUSION: Difference between the result of this study and the data of GBD study in the mean disability weight for AD and PD was noticed.