EEG/MEG- and imaging-based diagnosis of Alzheimer's disease.

In recent years, researchers have embarked on a search of computer-aided methods for diagnosis of the Alzheimer's disease (AD) to help clinicians make the diagnosis earlier and more accurately such that treatment of the disease can begin sooner when there is a higher chance of success in slowing down the progression of this disease. This article presents a review of journal articles on brain signal- and image-based diagnosis of AD published in the past few years. The areas of signal processing, electroencephalogram and magnetoencephalogram are considered. In the area of image analysis, the following modalities are reviewed: magnetic resonance imaging (MRI), functional MRI, diffusion tensor MRI, and structural MRI. Computer-aided early diagnosis of the AD would be a major breakthrough with a very significant worldwide impact because medications would be able to slow down the progression of the disease. This review shows that this is a very active area in the frontier of brain research, with many multidisciplinary researchers exploring a variety of approaches using various types of brain signals and imaging technologies. The brain signal-based approaches will be able to point toward early onset diagnosis of the AD, but as the disease progresses, a multimodal approach can increase the accuracy of the diagnosis.