Clinical Prediction of Progression from Mild Cognitive Impairment to Alzheimer’s Disease

The featured paper is ‘Clinical prediction of Alzheimer Disease Dementia across the spectrum of Mild Cognitive Impairment’ by Dickerson et al.

In the introduction, the authors argue that in Mild Cognitive Impairment (MCI), if the disease process which may lead to Alzheimer’s Disease is identified at an early stage then there should be greater chances of preventing progression. The 5 year follow-up period in this study is suggested as being meaningful in terms of developing early intervention trials. The authors were also interested in the clinical utility of neuropsychological testing and the ‘Clinical Dementia Rating’ scores. The authors state their aim of predicting the clinical course of MCI using a number of baseline measures including those discussed above.

Subjects were taken from a longitudinal study already underway, giving what the authors describe as ‘approximately 5 years of follow-up’ in 244 subjects. The people in the longitudinal study were over the age of 65 and free vascular risk factors and of concurrent illness (including medical and psychiatric) which  perhaps represents a relatively select group. During the course of the study formal diagnostic criteria were used both for those developing dementia and also for identifying MCI. A neuropsychological test battery was administered which focused on verbal memory and executive functioning

There were 42 subjects with MCI  and 125 with very mild MCI. The latter group were identified retrospectively using a tight set of criteria which included scoring below 0.5 on the Clinical Dementia Rating scale, an objective measure of memory impairment and preservation of general intellectual functioning. The vMCI group were followed up for an average of 4.5 years and were more likely than the control group (without MCI) to develop Alzheimer’s Disease. Alzheimer’s Disease was predicted by CDR scores, executive functioning and vebal memory. The authors conclude that vMCI is a clinical useful diagnostic entity which predicts a higher conversion rate to Alzheimer’s Disease than in those without MCI or vMCI. While there are a number of findings in this study, the concept of vMCI is a very useful one particularly if the expected rise in prevalence of dementia is considered.



The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.

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