Official Title: “A Methodology Study to Assess the Feasibility of Using Functional Magnetic Resonance Imaging (fMRI) to Quantify the Effects of Analgesic Drugs in Post-Traumatic Neuropathic Pain Subjects”

This study is a methodology study designed to discover whether a brain imaging technology is a better way of compare the relative sensitivities of fMRI and subjective psychometric assessments of pain to multiple doses of pregabalin and tramadol SR in a cross-over clinical study design.

Study Type: Interventional

Study Design: Treatment, Randomized, Double Blind (Subject, Caregiver, Investigator), Crossover Assignment, Pharmacodynamics Study

Intervention(s) in this Clinical Trial

• Drug: Pregabalin
  • Dose 75 mg titrated to 150 mg, bid
• Drug: Placebo
  • BID
• Drug: Tramadol SR
  • Dose 50mg titrated to 200 mg, bid

Arms, Groups and Cohorts in this Clinical Trial

• Placebo Comparator: 1
• Experimental: 2
• Experimental: 3

Primary Measures

• Voxel-wise BOLD and ASL brain activation signals across the whole brain and in defined brain regions in response to painful (brush allodynia and heat) stimuli, ongoing pain and visual (checkerboard) stimuli
  • Time Frame: 7 days
    Safety Issue?: No

Secondary Measures

• Daily Pain Score
  • Time Frame: 7 days
    Safety Issue?: No
• Present Pain Intensity score
  • Time Frame: 7 days
    Safety Issue?: No
• Psychological assessment scores
  • Time Frame: 7 days
    Safety Issue?: No
• Neuropathic Pain Symptom Inventory score
  • Time Frame: 7 days
    Safety Issue?: No
• Doleur neuropathic 4 "DN4" results
  • Time Frame: 7 days
    Safety Issue?: No

Inclusion Criteria:

• Diagnosis of post-traumatic peripheral NeP syndrome, including post-surgical NeP.
• Presence of dynamic mechanical allodynia (brush allodynia) in the dermatomes associated with specific dermatomes.
• Brush allodynia score of ≥4 and calculated average pain score of ≥4 on an 11-point numerical rating scale by the completion of down-titration of existing medications.
• Right-handed

Exclusion Criteria:

• Subjects with trigeminal neuralgia, central pain (due to cerebrovascular lesions, multiple sclerosis and/or traumatic spinal cord injuries including spinal surgery).
• Complex region pain syndromes, phantom limb pain, radiculopathy, painful diabetic neuropathy or post- Herpetic neuralgia.
• Subjects with any other co-existing pain which he/she or a qualified pain physician cannot differentiate from NeP of peripheral origin.
• Subjects with diabetes mellitus and with an HbA1C value of >10% upon measurement at screening.

Gender Eligibility for this Clinical Trial: Both

Minimum Age for this Clinical Trial: 18 Years

Maximum Age for this Clinical Trial: 75 Years

Are Healthy Volunteers Accepted for this Clinical Trial?: No

Lead Sponsor: Pfizer

Overall Clinical Trial Officials and Contacts

Pfizer CT.gov Call Center Study Director Pfizer  

Overall Contact: Pfizer CT.gov Call Center 1-800-718-1021 

Information obtained from ClinicalTrials.gov on August 08, 2008

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00610155

Study ID Number: A0081173

ClinicalTrials.gov Identifier: NCT00610155

Health Authority: United Kingdom: Research Ethics Committee

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