Effects of Ketamine on Eye Movements, Perception and Brain Function

Functional Neuroimaging Clinical Trial

Official title:

Effects of Ketamine on Eye Movements, Perception and Brain Function

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02701933
• Other study ID #: #14-03-20
• Status: Completed
• Phase: N/A
• First received: February 17, 2016
• Last updated: March 2, 2016
• Start date: April 2014
• Est. completion date: December 2014

Study information

• Verified date: March 2016
• Source: University of Bonn
• Contact: n/a
• Is FDA regulated: No
• Health authority: Germany: Ethics Commission
• Study type: Interventional

Clinical Trial 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.

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).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 24
• Est. completion date: December 2014
• Est. primary completion date: December 2014
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 18 Years to 45 Years

Eligibility

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

Study Design

Allocation: Randomized, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Functional Neuroimaging

Intervention

Drug:
• Ketamine
Racemic ketamine, intravenous, at a concentration of 10mg ketamine per 50ml infusion
• Saline
Saline, intravenous infusion

Locations

Country	Name	City	State
Germany	University of Bonn	Bonn	NRW

Sponsors (1)

Lead Sponsor	Collaborator
University of Bonn

Country where clinical trial is conducted

Germany, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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	No
Secondary	Psychotomimetic State Inventory (PSI)		within 1 hour of start of IV infusion	No
Secondary	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	No
Secondary	d2 Attention Test, a measure of sustained attention	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	within 1 hour of start of IV infusion	No
Secondary	Recognition memory performance (latencies in ms)		after 5 days of washout period	No
Secondary	Recognition memory performance (percent correct responses)		after 5 days of washout period	No
Secondary	Smooth pursuit gain (%)		within 1 hour of start of IV infusion	No
Secondary	Smooth pursuit root mean square error (RMSE)		within 1 hour of start of IV infusion	No
Secondary	Smooth pursuit saccadic frequency (number per second)		within 1 hour of start of IV infusion	No
Secondary	Prosaccade latency (ms)		within 1 hour of start of IV infusion	No
Secondary	Prosaccade gain (%)		within 1 hour of start of IV infusion	No
Secondary	Prosaccade spatial error (%)		within 1 hour of start of IV infusion	No
Secondary	Prosaccade velocity (degrees per second)		within 1 hour of start of IV infusion	No
Secondary	Prosaccade error rate (%)		within 1 hour of start of IV infusion	No
Secondary	Antisaccade latency (ms)		within 1 hour of start of IV infusion	No
Secondary	Antisaccade gain (%)		within 1 hour of start of IV infusion	No
Secondary	Antisaccade spatial error (%)		within 1 hour of start of IV infusion	No
Secondary	Antisaccade velocity (degrees per second)		within 1 hour of start of IV infusion	No
Secondary	Antisaccade error rate (%)		within 1 hour of start of IV infusion	No