QSPainRelief-patientCNS : Clinical Biomarkers of Nociception, Sedation and Cognition

Summary

QSPainRelief-patientCNS is a monocentric prospective longitudinal study conducted in patients suffering from disabling post-surgical pain for which the treating physician is about to prescribe a given drug combination for the treatment of their pain with the aim of identifying measures of drug-induced effects on CNS activity that could be used as biomarkers of real-life clinical outcome, both in terms of desired treatment effects (treatment-induced pain relief) but also in terms of undesired treatment effects (treatment-induced sedation and treatment-induced cognitive dysfunction).

Conditions

• Post-operative Pain

Interventions

DIAGNOSTIC_TEST

Scalp electroencephalography (EEG)

Resting EEG will be recorded before initiation of the combination treatment (visit 1) and 7-10 days after treatment (visit 2). Drug-induced sedation-related changes in the EEG frequency spectrum. Five minutes of resting EEG eyes-open will be recorded in a quiet room while participants are asked to focus on an image displayed on a wall. Then, they will be asked to close their eyes for an additional 2 minutes. The alpha power ratio eyes open/eyes closed will be computed (alpha attenuation coefficient; Kaida et al., 2006). Changes in this coefficient will be used as a measure of drug-induced sedation.

DIAGNOSTIC_TEST

Laser-evoked potentials (LEPs)

Laser-evoked potentials (LEPs) will be recorded before (visit 1) and 7-10 after (visit 2) initiating the combination treatment. Short pulses (50-100 ms) of radiant heat generated by a C02 laser stimulator will be applied to the skin of the left or right hand dorm to briefly and selectively activate heat-sensitive pain receptors. A concomitant EEG recordings will be used to measure the amplitude and latency of the elicited laser-evoked potentials. Changes in LEP amplitude (expressed as percentage of change) will be used as a measure of drug-induced effects on the state of the thermonociceptive system.

DIAGNOSTIC_TEST

Cognitive auditory-evoked potentials (P300)

Cognitive auditory-evoked potentials will be recorded before (visit 1) and 7-10 after (visit 2) initiating the combination treatment. Short-lasting auditory tones will be delivered using a three-stimulus oddball paradigm combining standard tones (90% of stimuli), slightly different target tones that the subject must attend and detect (10% of stimuli), and strongly different distractor non-target tones (10% of stimuli). The stimuli will be delivered binaurally using headphones. Participants will be instructed to press a button when they detect a target tone, and to ignore the standard and distractor non-target tones. The EEG recordings will be used to measure the amplitude and latency of the cognitive P3a and P3b potentials (Komerchero \& Polich 1999). Changes in P3a/P3b amplitude will be used as a measure of drug-induced effects on cognition (expressed as percentage of change).

DIAGNOSTIC_TEST

Cervical somatosensory-evoked potentials

Cervical spinal-cord evoked potentials will be recorded before (visit 1) and 7-10 after (visit 2) initiating the combination treatment. The responses will be elicited by transcutaneous electrical stimulation of the median nerve. The N13 component of this response is mediated by large myelinated non-nociceptive fibers and reflects a segmental postsynaptic response of dorsal horn interneurons at the level of lumbar spinal cord (Cruccu et al., 2008). Changes in magnitude of the N13 will be used as a measure of drug-induced effects on spinal cord function (expressed as percentage of change).

DIAGNOSTIC_TEST

Pupillometry

Pupillometry measurements will be performed before (visit 1) and 7-10 after (visit 2) initiating the combination treatment. Pupillometry has been proposed as a method to assess opioid pharmacodynamics. The extent of pupil dilatation can provide an index of nociceptive input via autonomic innervation of the iris muscles, while the extent of the attenuation of this pupillary response during exposure to opioid analgesics could provide an index of pharmacological effects reflecting the extent of opioid receptor occupancy in the CNS. Pupillometry (static pupil diameter, variability of pupil diameter \[variation coefficient of pupillary dilation, VCPD, Charier et al. 2017\]), light-evoked speed of pupil constriction \[maximum pupil constriction velocity, PCV, Connely et al., 2014\]) will be measured using a handheld pupillometry device routinely used for clinical evaluations.

DIAGNOSTIC_TEST

Saccadic Peak Velocity

The saccadic peak velocity (SPV; m/s) will be measured before before (visit 1) and 7-10 after (visit 2) initiating the combination treatment. Saccadic peak velocity is one of the most sensitive parameters for sedation. Recording of eye movements will be performed in a quiet room with dimmed lightning. Average values of saccadic peak velocity (expressed as degrees/second) of all correct saccades will be measured.

DIAGNOSTIC_TEST

Adaptive tracking test

The test will be performed before (visit 1) and 7-10 after (visit 2) initiating the combination treatment. Adaptive tracking is a pursuit-tracking task sensitive to impairment of eye-hand coordination by drugs. It has been proven useful for measuring CNS effects of alcohol, various other psychoactive drugs, and sleep deprivation.

DIAGNOSTIC_TEST

Body Sway Test

Body sway will be assessed before (visit 1) and 7-10 after (visit 2) initiating the combination treatment, using a body sway meter and with eyes closed. The body sway meter allows measurement of body movements in a single plane, providing a measure of postural stability. The method has been used to demonstrate effects of sleep deprivation, ethanol and psychoactive drugs. All body movements over a 2-min period are integrated and expressed as millimeters of sway.

DIAGNOSTIC_TEST

N-back working memory test

Working memory performance will be assessed before (visit 1) and 7-10 after (visit 2) initiating the combination treatment. In this test, a series of letters are shown to the participant on a computer screen. The test includes three conditions with increased working memory load. The "0-back" condition simply requires to indicate whether the presented letter is the letter "X" or another letter. In the "1-back" condition, participants are requested to indicate whether the displayed letter is identical to the preceding letter. In the "2-back" condition, participants are required indicate whether the letter is repeated with one other letter in between (e.g., B … C … B).

OTHER

Patient-reported outcomes

Before (visit 1) and 7-10 after (visit 2) initiating the combination treatment, but also daily between the two visits, 14 days, 1 month, 3 months and 6 months after treatment initiation, patient-reported outcomes will be collected to assess clinical effects and side-effects of the combination treatmen These include the short form of the Brief Pain Inventory (BPI), the PROMIS PQ-NEURO score for neuropathic pain, the Stanford Sleepiness Scale (SSS), and the PROMIS Neuro-QOL self-assessment of cognitive functioning.

Sponsors & Collaborators

• Cliniques universitaires Saint-Luc- Université Catholique de Louvain

  collaborator OTHER

• Université Catholique de Louvain

  lead OTHER

Study Design

Allocation

NA

Purpose

DIAGNOSTIC

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2021-03-15

Primary Completion

2024-09-30

Completion

2024-09-30

Countries

• Belgium

Study Locations