Visual P2-N2 complex and arousal at the time of encoding predict the time domain characteristics of amnesia for multiple intravenous anesthetic drugs in humans Journal Article
| Authors: | Pryor, K. O.; Reinsel, R. A.; Mehta, M.; Li, Y.; Wixted, J. T.; Veselis, R. A. |
| Article Title: | Visual P2-N2 complex and arousal at the time of encoding predict the time domain characteristics of amnesia for multiple intravenous anesthetic drugs in humans |
| Abstract: | Background: Intravenous anesthetics have marked effects on memory function, even at subclinical concentrations. Fundamental questions remain in characterizing anesthetic amnesia and identifying affected system-level processes. The authors applied a mathematical model to evaluate time-domain components of anesthetic amnesia in human subjects. Methods: Sixty-one volunteers were randomized to receive propofol (n = 12), thiopental (n = 13), midazolam (n = 12), dexmedetomidine (n = 12), or placebo (n = 12). With drug present, subjects encoded pictures into memory using a 375-item continuous recognition task, with subsequent recognition later probed with drug absent. Memory function was sampled at up to 163 time points and modeled over the time domain using a two-parameter, first-order negative power function. The parietal event-related P2-N2 complex was derived from electroencephalography, and arousal was repeatedly sampled. Each drug was evaluated at two concentrations. Results: The negative power function consistently described the course of amnesia (mean R = 0.854), but there were marked differences between drugs in the modulation of individual components (P < 0.0001). Initial memory strength was a function of arousal (P = 0.005), whereas subsequent decay was related to the reaction time (P < 0.0001) and the P2-N2 complex (P = 0.007/0.002 for discrete components). Conclusions: In humans, the amnesia caused by multiple intravenous anesthetic drugs is characterized by arousal-related effects on initial trace strength, and a subsequent decay predicted by attenuation of the P2-N2 complex at encoding. The authors propose that the failure of normal memory consolidation follows drug-induced disruption of interregional synchrony critical for neuronal plasticity and discuss their findings in the framework of memory systems theory. © 2010, the American Society of Anesthesiologists, Inc. |
| Keywords: | adolescent; adult; controlled study; middle aged; young adult; major clinical study; clinical trial; placebo; controlled clinical trial; midazolam; propofol; prediction; mathematical model; predictive value of tests; memory; psychomotor performance; recognition; intravenous anesthesia; amnesia; task performance; anesthetics, intravenous; electroencephalography; parietal lobe; dexmedetomidine; thiopental; memory consolidation; reaction time; evoked potentials, visual; arousal; evoked visual response |
| Journal Title: | Anesthesiology |
| Volume: | 113 |
| Issue: | 2 |
| ISSN: | 0003-3022 |
| Publisher: | Lippincott Williams & Wilkins |
| Date Published: | 2010-08-01 |
| Start Page: | 313 |
| End Page: | 326 |
| Language: | English |
| DOI: | 10.1097/ALN.0b013e3181dfd401 |
| PUBMED: | 20613477 |
| PROVIDER: | scopus |
| PMCID: | PMC2910207 |
| DOI/URL: | |
| Notes: | --- - "Cited By (since 1996): 1" - "Export Date: 20 April 2011" - "CODEN: ANESA" - "Source: Scopus" |
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