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Effects of Ketamine on Eye Movements, Perception and Brain Function

Sponsor
University of Bonn (Other)
Overall Status
Completed
CT.gov ID
NCT02701933
Collaborator
(none)
24
Enrollment
1
Location
2
Arms
8
Duration (Months)
3
Patients Per Site Per Month

Study Details

Study Description

Brief Summary

In this study, the investigators examine the effects of low-dose ketamine on different oculomotor, perceptual and cognitive functions. They also examine effects on concurrent brain activity using blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI). A sample of N=25 healthy, male participants is required to complete the study. The design is within-subjects, placebo-controlled, double-blind and cross-over. A targeted ketamine level in plasma of 100ng/ml is applied. It is hypothesised that ketamine, compared to placebo, will lead to changes in task performance and brain activity similar to those observed in patients with schizophrenia.

Condition or Disease Intervention/Treatment Phase
N/A

Detailed Description

The uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist ketamine has been proposed as a model system of the symptoms of schizophrenia. To complement this model system and to allow neurobiological as well as translational studies, biomarkers are often applied to people under the influence of ketamine. Here, we apply oculomotor, perceptual and cognitive biomarkers to healthy human volunteers whilst they undergo BOLD fMRI at 3 Tesla field strength. We use a counter-balanced, placebo-controlled, double-blind, within-subjects design. A sample of 25 healthy participants is required. Participants will receive intravenous (IV) racemic ketamine (with a 100ng/ml target plasma concentration) on one of two assessment days and they will receive placebo (intravenous saline) on the other assessment day. BOLD fMRI will be carried out on a Siemens Trio scanner at the Life&Brain Centre, Bonn. In addition to brain functional and cognitive, perceptual and oculomotor responses, we will also measure self-ratings of psychosis-like experiences. These will be obtained using the Psychotomimetic States Inventory (PSI; Mason et al 2008).

Study Design

Study Type:
Interventional
Actual Enrollment :
24 participants
Allocation:
Randomized
Intervention Model:
Crossover Assignment
Masking:
Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose:
Basic Science
Official Title:
Effects of Ketamine on Eye Movements, Perception and Brain Function
Study Start Date :
Apr 1, 2014
Actual Primary Completion Date :
Dec 1, 2014
Actual Study Completion Date :
Dec 1, 2014

Arms and Interventions

Arm Intervention/Treatment
Other: Ketamine-Saline

Each participant receives both ketamine and placebo (saline) in randomised order in a repeated-measures design. In this arm, ketamine is administered on the first assessment and placebo (saline) is administered on the second assessment.

Drug: Ketamine
Racemic ketamine, intravenous, at a concentration of 10mg ketamine per 50ml infusion
Other Names:
  • Ketamin Ratiopharm

    • Drug: Saline
    Saline, intravenous infusion
    Other Names:
  • Kochsalzloesung

    		•
    Other: Saline-Ketamine

    Each participant receives both ketamine and placebo (saline) in randomised order in a repeated-measures design. In this arm, placebo (saline) is administered on the first assessment and ketamine is administered on the second assessment.

    Drug: Ketamine
    Racemic ketamine, intravenous, at a concentration of 10mg ketamine per 50ml infusion
    Other Names:
  • Ketamin Ratiopharm

    • Drug: Saline
    Saline, intravenous infusion
    Other Names:
  • Kochsalzloesung

    		•

    Outcome Measures

    Primary Outcome Measures

    1. Brain activity in cortical and subcortical areas as assessed using BOLD (blood oxygen level dependent) functional magnetic resonance imaging (fMRI) at 3 Tesla field strength [within 1 hour of start of IV infusion]

    Secondary Outcome Measures

    1. Psychotomimetic State Inventory (PSI) [within 1 hour of start of IV infusion]

    2. Visual Analogue Rating Scales (VARS) from Norris 1971; self-rating scores of the subscales "mental sedation", "physical sedation", "tranquillisation" and "other feelings and attitudes" [within 1 hour of start of IV infusion]

    3. d2 Attention Test, a measure of sustained attention [within 1 hour of start of IV infusion]

      The test requires the crossing out of the letter d combined with two dashes amidst letters d and p combined with one, two, three or four dashes and is a well-established measure of sustained attention

    4. Recognition memory performance (latencies in ms) [after 5 days of washout period]

    5. Recognition memory performance (percent correct responses) [after 5 days of washout period]

    6. Smooth pursuit gain (%) [within 1 hour of start of IV infusion]

    7. Smooth pursuit root mean square error (RMSE) [within 1 hour of start of IV infusion]

    8. Smooth pursuit saccadic frequency (number per second) [within 1 hour of start of IV infusion]

    9. Prosaccade latency (ms) [within 1 hour of start of IV infusion]

    10. Prosaccade gain (%) [within 1 hour of start of IV infusion]

    11. Prosaccade spatial error (%) [within 1 hour of start of IV infusion]

    12. Prosaccade velocity (degrees per second) [within 1 hour of start of IV infusion]

    13. Prosaccade error rate (%) [within 1 hour of start of IV infusion]

    14. Antisaccade latency (ms) [within 1 hour of start of IV infusion]

    15. Antisaccade gain (%) [within 1 hour of start of IV infusion]

    16. Antisaccade spatial error (%) [within 1 hour of start of IV infusion]

    17. Antisaccade velocity (degrees per second) [within 1 hour of start of IV infusion]

    18. Antisaccade error rate (%) [within 1 hour of start of IV infusion]

    Eligibility Criteria

    Criteria

    Ages Eligible for Study:
    18 Years to 45 Years
    Sexes Eligible for Study:
    Male
    Accepts Healthy Volunteers:
    Yes
    Inclusion Criteria:

    • MRI-suitability

    • suitability for video-based combined pupil and corneal reflection (VCPCR) eye-tracking

    • good command of German language

    • willingness to take part

    Exclusion Criteria:

    • any current or history of axis I disorder diagnosis as assessed by the Mini-International Neuropsychiatric Interview (M.I.N.I.)

    • any neurological conditions and heart conditions

    • use of any prescription or non-prescription medication up to one week before participation

    • personal history of head-injuries, loss of consciousness, eye surgery or impairment of vision (other than corrective lenses)

    • any other relevant medical conditions such as high blood pressure

    • positive urine drug test (Drug-Screen Multi "5T", nal von minden GmbH)

    • history of drug use or current drug use

    • under- or overweight (below 18.5 and above 24.9 body mass index (BMI) values)

    • any diagnosis of psychotic disorders among first-degree relatives

    Contacts and Locations

    Locations

    Site City State Country Postal Code
    1 University of Bonn Bonn NRW Germany 53111

    Sponsors and Collaborators

    • University of Bonn

    Investigators

    • Principal Investigator: Ulrich Ettinger, PhD, Department of Psychology, University of Bonn

    Study Documents (Full-Text)

    None provided.

    More Information

    Publications

    None provided.
    Responsible Party:
    Ulrich Ettinger, Professor of Psychology, University of Bonn
    ClinicalTrials.gov Identifier:
    NCT02701933
    Other Study ID Numbers:
    • #14-03-20
    First Posted:
    Mar 8, 2016
    Last Update Posted:
    Mar 8, 2016
    Last Verified:
    Mar 1, 2016
    Individual Participant Data (IPD) Sharing Statement:
    No
    Plan to Share IPD:
    No
    Additional relevant MeSH terms:
    Ketamine

    Study Results

    No Results Posted as of Mar 8, 2016