title: Cholinesterase inhibitors affect brain potentials in amnestic mild cognitive impairment.
abstract: Amnestic mild cognitive impairment (MCI) is an isolated episodic memory disorder that has a high likelihood of progressing to Alzheimer's disease. Auditory sensory cortical responses (P50, N100) have been shown to be increased in amplitude in MCI compared to older controls. We tested whether (1) cortical potentials to other sensory modalities (somatosensory and visual) were also affected in MCI and (2) cholinesterase inhibitors (ChEIs), one of the therapies used in this disorder, modulated sensory cortical potentials in MCI. Somatosensory cortical potentials to median nerve stimulation and visual cortical potentials to reversing checkerboard stimulation were recorded from 15 older controls and 15 amnestic MCI subjects (single domain). Results were analyzed as a function of diagnosis (Control, MCI) and ChEIs treatment (Treated MCI, Untreated MCI). Somatosensory and visual potentials did not differ significantly in amplitude in MCI subjects compared to controls. When ChEIs use was considered, somatosensory potentials (N20, P50) but not visual potentials (N70, P100, N150) were of larger amplitude in untreated MCI subjects compared to treated MCI subjects. Three individual MCI subjects showed increased N20 amplitude while off ChEIs compared to while on ChEIs. An enhancement of N20 somatosensory cortical activity occurs in amnestic single-domain MCI and is sensitive to modulation by ChEIs.
authors.affiliation: Department of Neurology and Institute for Brain Aging and Dementia, University of California, Irvine, CA 92627, USA. ririmaji@uci.edu
authors.forename: Rie
authors.initials: R
authors.lastname: Irimajiri
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Michalewski
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Golob
authors.forename: Arnold
authors.initials: A
authors.lastname: Starr
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000110:Acetylcholinesterase / Q000187:drug effects / Q000378:metabolism; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000187:drug effects / Q000502:physiology; D000647:Amnesia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002800:Cholinesterase Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D003072:Cognition Disorders / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects* / Q000502:physiology; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects / Q000502:physiology; D005074:Evoked Potentials, Visual / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D009483:Neuropsychological Tests; D018697:Nootropic Agents / Q000494:pharmacology / Q000627:therapeutic use; D010775:Photic Stimulation; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D016896:Treatment Outcome
chemical_list: D002800:Cholinesterase Inhibitors; D018697:Nootropic Agents; D000110:Acetylcholinesterase; D000109:Acetylcholine