title: Relevance of in vivo neurophysiological biomarkers for mild cognitive impairment and Alzheimer's disease.
abstract: Visuospatial dysfunction including defects in motion perception in Alzheimer's disease (AD) and mild cognitive impairment (MCI) are clues to search for potential in vivo biomarkers. In this review, we focus on the clinical relevance of non-invasive neurophysiological findings in event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI) to assess visual dysfunction in AD and MCI. We first summarize the current concept of the parallel visual pathways in primates and humans. Next, we outline the results of previous electrophysiological and fMRI studies on visual function in AD and MCI. Finally, we present the recent findings of our systematic ERP and fMRI approach to visual perception in AD and MCI. Our overview strongly indicates that visual impairments in patients with AD and MCI are mainly caused by dysfunction in higher-level parallel visual pathways. In particular, a deficit in ventro-dorsal stream function related to optic flow perception is responsible for the earliest and most prominent visual symptoms in MCI. Therefore, we conclude that ERP and fMRI measurements for visual perception can be used as in vivo biomarkers for early functional brain changes in MCI and AD patients.
authors.affiliation: Department of Clinical Neurophysiology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. yamasa@neurophy.med.kyushu-u.ac.jp
authors.forename: Takao
authors.initials: T
authors.lastname: Yamasaki
authors.forename: Shizuka
authors.initials: S
authors.lastname: Horie
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Muranaka
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Kaseda
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Mimori
authors.forename: Shozo
authors.initials: S
authors.lastname: Tobimatsu
mesh_terms: D000544:Alzheimer Disease / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D000818:Animals; D015415:Biomarkers; D060825:Cognitive Dysfunction / Q000503:physiopathology* / Q000523:psychology; D004594:Electrophysiology; D006801:Humans; D009482:Neurophysiology; D011323:Primates / Q000502:physiology; D014786:Vision Disorders / Q000209:etiology / Q000503:physiopathology; D014795:Visual Pathways / Q000503:physiopathology; D014796:Visual Perception
chemical_list: D015415:Biomarkers