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Completed

NCT Number: NCT01911195

Reconstructing Consciousness and Cognition

Currently it is unknown how the human brain reorganizes its network organization to generate conscious experience and cognitive activity after a period of unconsciousness. Therefore, the purpose of this study is to assess how cognitive activity is reconstructed after general anesthesia. The investigators hypothesize that the brain's transition from unconsciousness to consciousness and full cognition is a complex process that occurs over an extended period of time. Specifically, the investigators hypothesize the following order of cognitive reconstitution: responsiveness to command, attention, complex scanning and visual tracking, working memory, and executive function.

Volunteers will be healthy participants who are anesthetized with commonly used anesthetic drugs as well as a non-anesthetized group to control for circadian influences. A total of 60 subjects will be recruited for this study. All subjects (male and female) will perform basic tests for cognition on a laptop computer at 30-minute intervals during this study. The testing battery to be administered was assembled to assess multiple cognitive functions in order to determine whether and how cognitive processes return to baseline function. Electroencephalogram (measuring brain electrical activity) data will be monitored and recorded during both anesthesia and cognitive testing, for subsequent analysis.

This study is significant because it could lead to a better understanding of the neural correlates of human consciousness, as well as normal and abnormal conscious state transitions (including barriers to such transitions).

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Key information

Conditions

Postoperative Cognitive Dysfunction Cognition Disorders Cognitive Dysfunction Mental Disorders Neurocognitive Disorders Pathologic Processes Pathological Conditions, Signs and Symptoms Postoperative Cognitive Complications Postoperative Complications

Age range

20 year–40 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Michigan, Ann Arbor, Michigan, United States

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Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Healthy 20-40 year old volunteers,
  • American Society of Anesthesiologists Physical Status I or II (i.e., healthy),
  • Body mass index < 30 kg/m2,
  • Easily visualized uvula,
  • With anticipated equal recruitment of males and females.

Exclusion criteria

  • Physical signs suggestive of difficult airway (e.g., mouth opening <3cm, short distance between the chin and neck, poor mandibular subluxation, thick neck),
  • History of obstructive sleep apnea,
  • Reactive airway disease,
  • Neuropsychiatric disorders,
  • History or current use of psychotropic medications,
  • Current tobacco and alcohol use,
  • History of hypertension or current medication for blood pressure control, cardiovascular disease or arrhythmias,
  • Positive urine toxicology screen,
  • History of reflux,
  • Pregnancy,
  • Family history of problems with anesthesia (including but not limited to malignant hyperthermia),
  • Sleep disorders,
  • History of postoperative nausea/vomiting or motion sickness,
  • Allergy to eggs, egg products or soy.

Treatment and study plan

ISOFLURANE- Experimental Arm

Drug

The experimental group will be given the anesthetic isoflurane for three hours, and will undergo cognitive tests immediately following emergence from general anesthesia while connected to an EEG machine.

Control Group: Cognitive Testing

Other

The control group will undergo cognitive testing while connected to an EEG machine following a comparable rest period, but will not receive general anesthesia.

Primary outcomes

  1. Neurocognitive scores

    Time frame: Three hours following emergence from general anesthesia

    Neurocognitive battery performed on computer

Secondary outcomes

  1. Brain network connectivity

    Time frame: Three hours following emergence from general anesthesia

    Functional brain networks will be reconstructed from EEG data.

Sponsors and collaborators

Lead sponsor

University of Michigan

Other

Collaborators

  • James S McDonnell Foundation
  • University of Pennsylvania
  • Washington University School of Medicine

Registry information

Acronym: RCC

Important dates

Study start
2013
Primary completion
2015
Study completion
2015
First posted
Jul 30, 2013
Registry last updated
Feb 20, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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