Brain Effects of Opiate Agonist and Antagonist

Phase 4

Completed

Conditions: Chronic Low-back Pain

Interventions: Drug: Morphine

Registration Number: NCT04342130

Lead Sponsor: University of Rochester

Brief Summary: This study will look at the short-term effect of morphine on brain response to food.

Detailed Description: Chronic low back pain patients and healthy controls will be recruited for this study. Participants' brain will be scanned at baseline and then again on a different day after the administration of an oral dose of 30 mg morphine in an open label design. Participants will receive morphine 60 minutes prior to the start of the second scanning session. The brain scans will include structural scans, functional scans at rest and functional scans during the ingestion of a highly caloric drink.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 10

Inclusion Criteria

Healthy participants
Patients in pain: suffering from persistent pain more days than not, 3/10 in intensity on a numerical rating scale, for at least 6 weeks or more.

Exclusion Criteria

Any DSM diagnosis
diabetes
food allergies
lactose intolerance
participants seeking to quit smoking or to lose weight
participants on any psychotropic medication including opiate based analgesics (e.g. oxycodone, methadone, suboxone)
pregnant or nursing women
pacemaker or other implanted electrical devices
Participants with a past history of head trauma or seizures
Any past history of illegal drug or alcohol misuse
Participants who cannot undergo an MRI scan.

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
All Participants	Morphine	People with low back pain who were given and oral dose of 30 mg morphine.

Primary Outcome Measures

Name	Time	Method
Mean Change in Subcortical Brain Structure Volume	baseline to 1 hour	Magnetic Resonance Imaging (MRI) scanning was performed to collect brain volume measurements in cc. There were 4 different areas of the brain that were analyzed.
Change in Brain Response to Highly Caloric Drink	baseline to 1 hour	Participants received a highly caloric drink and a tasteless solution during a functional MRI scanning session. A general linear model was used to generate the magnitude of the fit for each type of stimuli and differences between the fits were calculated. A within subject analysis approach was used to calculate the effect of an acute dose of morphine on brain response to the highly caloric drink. Participants contributed beta values that were averaged across subjects and based on the average and standard deviation, the software, FSL, calculated Z = 4.38. This value indicates 4.38 standard deviations away from the mean in a distribution with a mean of zero and standard deviation of 1, which is the definition of the Gaussian curve (Z-distribution). It is scientifically not valid to say there is a higher or lower brain response. A Z-score = 0 means no change from baseline in brain response; a Z-score different from zero indicates a change from baseline after the ingestion of morphine.
Mean Change in Resting Brain Activity in the Nucleus Accumbens	baseline to 1 hour	Participants were scanned at rest during a functional MRI session. The resting brain activity was measured as the Power spectral density slow-4 frequency band. Data collected in the frequency range 0 and 0.5 Hertz was analyzed. We examined the power spectral density in the range of 0.027 to 0.073 Hertz. The mean change is expressed as arbitrary units after a Fourier transformation of the data which cancels out the units. The mean change ranges from 0 to 175. The higher the number the more energy within that frequency band.

Secondary Outcome Measures

Name	Time	Method
Mean Change in Back Pain Intensity	baseline to 1 hour	Pain was rated using a visual analog scale ranging from 0-100 with 100 indicating the worst imaginable pain ever.