Somatosensory Profiling in Radicular Pain Patients And it's Correlation With Treatment Outcome

Study Overview
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Brief Summary
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The investigators hypothesize that there may exist different quantitative sensory profiles between radicular pain patients who respond and those who do not respond to the standard therapy of epidural steroid injections (ESI).

Detailed Description
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The investigators are comparing warm/cold sensation, heat/cold pain threshold, heat/cold pain tolerance, wind-up, and conditioned pain modulation (CPM) as measured by Quantitative Sensory Testing (QST) between subjects with a radicular pain condition. The investigators are comparing those who respond and those who do not respond to standard therapy (ESI) before and after the treatment.

Official Title
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Somatosensory Profiling in Radicular Pain Patients And it's Correlation With Treatment Outcome

Conditions
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Radiculopathy, Lower Extremity Radicular Pain

Intervention / Treatment
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* Device: Quantitative Sensory Testing (QST)
* Procedure: Epidural Steroid Injection (ESI)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: diagnosis of lower extremity radicular pain regardless of specific or suspected etiologies scheduling an epidural steroid injection (ESI) Exclusion Criteria: a major psychiatric disorder requiring a recent (within one month) hospitalization, such as major depression, bipolar disorder, schizophrenia, anxiety disorder, and psychosis subject is taking illicit or recreational drug detected through a urine toxicology screen subject has had an interventional pain management procedures within the last eight weeks that may alter QST responses including neuraxial or local anesthetic block subject had a change in dosage of neuromodulatory pain medication (including gabapentin, pregabalin, cymbalta, amitriptyline, nortriptyline, trileptal, etc) in the past two weeks subject is pregnant subject has pending litigation involving the current pain condition being treated and studied.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: >30% Pain Relief<br>All subjects have radicular pain and are scheduled to receive an epidural steroid injection (ESI) as a treatment. The ESI treatment is conducted by the subject's clinical physician and is not given as part of the research study procedures. Quantitative Sensory Testing (QST) will be conducted before and after the ESI treatment. QST consists of hot and cold temperature testing using the QST device. This group of subjects received greater than 30% pain relief. | Device: Quantitative Sensory Testing (QST)<br>* Subjects will undergo hot and cold temperature testing using the QST device at two points: 1) Before ESI and 2) after ESI.<br>Procedure: Epidural Steroid Injection (ESI)<br>* Subjects will receive an ESI by their clinical physician as part of their clinical treatment. This procedure is not given as part of the research study.<br>|
| Other: <30% Pain Relief<br>All subjects have radicular pain and are scheduled to receive an epidural steroid injection (ESI) as a treatment. The ESI treatment is conducted by the subject's clinical physician and is not given as part of the research study procedures. Quantitative Sensory Testing (QST) will be conducted before and after the ESI treatment. QST consists of hot and cold temperature testing using the QST device. This group of subjects received less than 30% pain relief. | Device: Quantitative Sensory Testing (QST)<br>* Subjects will undergo hot and cold temperature testing using the QST device at two points: 1) Before ESI and 2) after ESI.<br>Procedure: Epidural Steroid Injection (ESI)<br>* Subjects will receive an ESI by their clinical physician as part of their clinical treatment. This procedure is not given as part of the research study.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pre-epidural Warm Sensation Quantitative Sensory Testing (QST) Results | QST tests for changes in spinal nerves. A small metal plate, called a thermode, is placed on the subject's arm. During the warm sensation test, the plate slowly increases in temperature.The subject will stop the test as soon as the plate feels warm. This temperature is recorded and can range from 32-53 degrees Celsius. The same test is repeated on the subject's leg that has radicular pain. The difference in temperatures from the test on the subject's arm and leg were analyzed. | Baseline measurement before the epidural injection | 
| Post-epidural Continued Pain Modulation (CPM) | CPM is a type of QST where the thermode is placed on the subject's non painful arm. Heat stimulation (47 degrees C, 4 seconds) was delivered to the thermode 4 times and the subject rated the pain felt by the heat stimulation on a visual analog scale (VAS) of 0-10. During the second heat stimulation, the subject immersed their hand (opposite from the arm with the thermode) in 12 degree C water and then rated the pain felt by the heat on a VAS of 0-10 (10 is the worst pain a subject can imagine, 0 is no pain). The final 2 heat stimuli were delivered (without using the hand submerged in water). This same test was repeated with the thermode on the subject's leg with radicular pain. The subject placed their hand contralateral to the painful leg in the cold water during the second heat stimulation. The VAS scores from each heat stimulation were averaged for the non-painful arm and the painful leg. The difference in averages between the arm and leg were then analyzed. | 4 weeks after the epidural injection | 
| Post-epidural Cold Pain Threshold QST Results | The thermode is placed on the subject's arm. During the cold pain threshold test, the plate slowly decreases in temperature.The subject will stop the test when the plate is at their minimal tolerable temperature. This temperature is recorded and can range from 32-0 degrees Celsius. The same test is repeated on the subject's leg that has radicular pain. The difference in temperatures from the test on the subject's arm and leg were analyzed. | 4 weeks after the epidural injection | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Radicular, Pain, Epidural Steroid Injection