Evidence map›Paper›PMID 27178861›Full record

ArticleClinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology2016

Electroencephalogram signatures of ketamine anesthesia-induced unconsciousness.

Oluwaseun Akeju, Andrew H Song, Allison E Hamilos, Kara J Pavone, Francisco J Flores, Emery N Brown, Patrick L Purdon

Registry-linked trialOpen access · bronzeAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT07138053 (The Impact of Multimodal Balancing Anesthesia vs Opioid Free Anesthesia on Postoperative Pain Intensity and Stress Response After Open Gynecology Surgery), which is not on this map. Cited by 110 papers, 2 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
110citing papers in PubMed, 2 pooled it
14.1field-weighted citation impact, top 1% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT07138053 naactive not recruitingnot on this mapstarted 2025, after this paper: background citation

The Impact of Multimodal Balancing Anesthesia vs Opioid Free Anesthesia on Postoperative Pain Intensity and Stress Response After Open Gynecology Surgery

TypeinterventionalSponsorCantonal Hospital ZenicaRan2025 to 2026Enrolled80ConditionsOpioid Free Anesthesia, Stress Response, Postoperative PainArmsOFA group
3 · Its place in the literature

Who cites it

110 citing papers in PubMed, 2 syntheses or guidelines pooled it, 223 citations in OpenAlex.

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  18. Cortical Mechanisms Contributing to Ketamine-Induced Dissociation.The Neuroscientist : a review journal bringing neurobiology, neurology and psychiatry · 2026
    Review
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  20. Article

50 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 3 institutions in 1 country.

Oluwaseun AkejuDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA. Electronic address: oluwaseun.akeju@mgh.harvard.edu.
Andrew H SongDepartment of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA.
Allison E HamilosHarvard Medical School, Boston, MA, USA; Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA; Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
Kara J PavoneDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA.
Francisco J FloresDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA.
Emery N BrownDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA; Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA; Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
Patrick L PurdonDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA.
Harvard University · USMassachusetts General Hospital · USMassachusetts Institute of Technology · US

Funding

PHD TRAINING IN NEUROSCIENCET32MH020017 · NIMH · HARVARD UNIVERSITY (MEDICAL SCHOOL) · PI JOHN ASSAD · 1997 to 2026
$15.8M
Redesigning General Anesthesia (Admin Supp)R01GM104948 · NIGMS · MASSACHUSETTS INSTITUTE OF TECHNOLOGY · PI BOYDEN, EDWARD S., BROWN, EMERY N · 2012 to 2016
$4.4M
A Systems Neuroscience Approach for the Study of General AnesthesiaDP1OD003646 · OD · MASSACHUSETTS GENERAL HOSPITAL · PI BROWN, EMERY N · 2007 to 2011
$4.4M
A Neural Systems Approach to Monitoring and Drug-Delivery for General AnesthesiaDP2OD006454 · OD · MASSACHUSETTS GENERAL HOSPITAL · PI PURDON, PATRICK L. · 2009 to 2009
$2.7M
NIGMS NIH HHS R01 GM104948NIH HHS DP1 OD003646NIH HHS DP2 OD006454NIMH NIH HHS T32 MH020017
6 · The paper itself

Abstract

objectivesKetamine is an N-methyl-d-aspartate (NMDA) receptor antagonist commonly administered as a general anesthetic. However, neural circuit mechanisms to explain ketamine anesthesia-induced unconsciousness in humans are yet to be clearly defined. Disruption of frontal-parietal network connectivity has been proposed as a mechanism to explain this brain state. However, this mechanism was recently demonstrated at subanesthetic doses of ketamine in awake-patients. Therefore, we investigated whether there is an electroencephalogram (EEG) signature specific for ketamine anesthesia-induced unconsciousness.

methodsWe retrospectively studied the EEG in 12 patients who received ketamine for the induction of general anesthesia. We analyzed the EEG dynamics using power spectral and coherence methods.

resultsFollowing the administration of a bolus dose of ketamine to induce unconsciousness, we observed a "gamma burst" EEG pattern that consisted of alternating slow-delta (0.1-4Hz) and gamma (∼27-40Hz) oscillations. This pattern was also associated with increased theta oscillations (∼4-8Hz) and decreased alpha/beta oscillations (∼10-24Hz).

conclusionsKetamine anesthesia-induced unconsciousness is associated with a gamma burst EEG pattern. SIGNIFICANCE: The EEG signature of ketamine anesthesia-induced unconsciousness may offer new insights into NMDA circuit mechanisms for unconsciousness.

Indexed as

Gamma RhythmAdultAnesthetics, GeneralBrainFemaleHumansKetamineMaleMiddle AgedAnesthetics, GeneralKetamineAnesthesiaEEGGamma oscillationsKetamineSlow oscillationsUnconsciousness

Identifiers

PMID27178861
PMCPMC4871620
OpenAlexW2301052761

What OpenQuestion holds

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Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.