Statistical quantity that gives an indication of how completely a fractal appears to fill space. It can be considered a measure of signal complexity.
Published in Chapter:
Fractal Dimension of the EEG in Alzheimer's Disease
Daniel Abásolo (University of Valladolid, Spain), Javier Escudero (University of Valladolid, Spain), Roberto Hornero (University of Valladolid, Spain), Pedro Espino (Hospital Clínico San Carlos, Spain), and Carlos Gómez (University of Valladolid, Spain)
Copyright: © 2008
|Pages: 7
DOI: 10.4018/978-1-59904-889-5.ch076
Abstract
Alzheimer’s disease (AD) is the most frequent cause of dementia in western countries, and is characterized by progressive impairments in cognition and memory, whose course lasts several years prior to death (Jeong, 2004). These clinical features are accompanied by histological changes in the brain, which include widespread cortical atrophy, intracellular deposition of neurofibrillary tangles, and extracellular deposition of senile plaques, particularly in the hippocampus and the cerebral cortex. Although a definite diagnosis is only possible by necropsy, a differential diagnosis with other types of dementia and with major depression should be attempted. Magnetic resonance imaging and computerized tomography can be normal in the early stages of AD, but a diffuse cortical atrophy is the main sign in brain scans. Mental status tests are also useful.