Combining imaging and assessment can predict Alzheimer's two years in advance18 December 2013 A combination of brain analysis by MRI with a neuropsychological assessment can accurately predict whether people with mild cognitive impairment get Alzheimer's disease within two years. The findings, by Sylvie Belleville, PhD, Director of Research at the Institut universitaire de gériatrie de Montréal, and her team have been published in the Journal of Alzheimer's Disease [1]. The strongest neuroimaging predictors were baseline cortical thickness in the right anterior cingulate and middle frontal gyri. For cognitive predictors, deficits in both free recall and recognition episodic memory tasks were highly suggestive of progression to dementia. Cortical thinning in the right anterior cingulate gyrus, combined to controlled and familiarity-based retrieval deficits, achieved a classification accuracy of 87.5%, a specificity of 90.9% and a sensitivity of 83.3%. This predictive model including both classes of measures provided more accurate predictions than those based on neuroimaging or cognitive measures alone. “At the moment, we can't diagnose this disease very early due to the lack of reliable protocols. Thus, there is a risk of erroneously identifying the disease when trying to diagnose it too early. Identifying markers that correctly predict the subsequent onset of more severe symptoms that are sensitive and specific considerably reduces the uncertainty of early diagnosis. The innovation here is showing that two different approaches can be combined to aid in diagnosis,” said Sylvie Belleville. “When used individually, neuroimaging and neuropsychology are effective but only up to a certain point. It is when combining and analyzing the results from both methods that we could achieve such an exceptional level of accuracy. “The clinical benefits of these extra two years are enormous. We can now evaluate the effectiveness of pharmacological and non-pharmacological therapies on the outcome of a clinical diagnosis of Alzheimer's disease in people identified with these tools. We could assess whether these treatments are more effective when administered earlier. "The questions we now need to answer are whether pharmacological treatment started at the onset of early warning signs will slow the illness and whether brain plasticity could be stimulated in a more structured way to delay symptoms that cause disability.” Reference 1. Belleville S, Peters F, Villeneuve S. Predicting Progression to Dementia in Elderly Subjects with Mild Cognitive Impairment Using Both Cognitive and Neuroimaging Predictors. Journal of Alzheimer’s Disease. 38(2):307-318.
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