title: A Potential VEP Biomarker for Mild Cognitive Impairment: Evidence from Selective Visual Deficit of Higher-Level Dorsal Pathway.
abstract: Visual dysfunctions are common in Alzheimer's disease (AD). Our aim was to establish a neurophysiological biomarker for amnestic mild cognitive impairment (aMCI). Visual evoked potentials (VEPs) were recorded in aMCI patients who later developed AD (n = 15) and in healthy older (n = 15) and younger controls (n = 15). Visual stimuli were optimized to separately activate lower and higher levels of the ventral and dorsal streams. We compared VEP parameters across the three groups of participants and conducted a linear correlation analysis between VEPs and data from neuropsychological tests. We then used a receiver operating characteristic (ROC) analysis to discriminate those with aMCI from those who were healthy older adults. The latency and phase of VEPs to lower-level stimuli (chromatic and achromatic gratings) were significantly affected by age but not by cognitive decline. Conversely, VEP latencies for higher-ventral (faces and kanji-words) and dorsal (kana-words and optic flow motion) stimuli were not affected by age, but they were significantly prolonged in aMCI patients. Interestingly, VEPs for higher-dorsal stimuli were related to outcomes of neuropsychological tests. Furthermore, the ROC analysis showed that the highest areas under the curve were obtained for VEP latencies in response to higher-dorsal stimuli. These results suggest aMCI-related functional impairment specific to higher-level visual processing. Further, dysfunction in the higher-level of the dorsal stream could be an early indicator of cognitive decline. Therefore, we conclude that VEPs associated with higher-level dorsal stream activity can be a sensitive biomarker for early detection of aMCI.
authors.affiliation: Department of Clinical Neurophysiology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.|Department of Neurology, Minkodo Minohara Hospital, Fukuoka, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Yamasaki
authors.affiliation: Department of Clinical Neurophysiology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Shizuka
authors.initials: S
authors.lastname: Horie
authors.affiliation: Department of Neurology and Geriatric Medicine, Graduate School of Medicine, Ehime University, Ehime, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Ohyagi
authors.affiliation: Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Tanaka
authors.affiliation: Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Norimichi
authors.initials: N
authors.lastname: Nakamura
authors.affiliation: Department of Occupational Therapy, Faculty of Rehabilitation, International University of Health and Welfare, Fukuoka, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Goto
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Kanba
authors.affiliation: Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Kira
authors.affiliation: Department of Clinical Neurophysiology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Shozo
authors.initials: S
authors.lastname: Tobimatsu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D060825:Cognitive Dysfunction / Q000150:complications*; D003118:Color Perception / Q000502:physiology; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D012372:ROC Curve; D012720:Severity of Illness Index; D014786:Vision Disorders / Q000175:diagnosis / Q000209:etiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Alzheimer’s disease; amnestic mild cognitive impairment; parallel visual pathways; visual evoked potentials; visual perception