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Center for Global Research Data

Phenotypic Characterization of Chronic Neuropathic Pain Following Post-Traumatic and Post-Surgical Injury

Lead Investigator: John Markman, University of Rochester
Title of Proposal Research: Phenotypic Characterization of Chronic Neuropathic Pain Following Post-Traumatic and Post-Surgical Injury
Vivli Data Request: 4326
Funding Source: No
Potential Conflicts of Interest: None

Summary of the Proposed Research:

More than 300 million surgeries are performed worldwide each year. Chronic pain after surgery typically lasts for more than 3 months after the operation, has a different feeling, and is often more intense than pain before surgery. This type of pain occurs in everyone or two of 10 surgical patients and is intolerable after roughly one of every 100 operations. This serious pain is more common after some types of surgery like those where the operation occurs in the chest to treat lung or breast cancer and influences how often this problem occurs and the severity of the pain. Nerve injury- related pain is a factor in one third of these patients. There is great unmet need for nonopioid analgesics for the treatment of nerve injury-related pain. A major barrier to optimizing treatment matching is a limited understanding of the relationship between sensory features identified on exam and by history and underlying pain mechanism. Additional study of this robustly phenotyped cohort with post-surgical and post traumatic neuropathic pain will address this barrier to improved pain diagnosis and treatment matching as well as superior clinical trial designs.

Statistical Analysis Plan:

The primary analyses would likely be an ANCOVA including terms be treatment, treatment x phenotype interaction, country of origin, trauma type, baseline pain score. The types of phenotypes that will be explored will include various neuropathic qualities (see list below for the variables we will use to make the phenotype qualities), baseline pain intensity, duration of pain since onset, concomitant medications, and native language. Missing data will be imputed using multiple imputation methods. Analyses will be performed using SAS or JMP software.

Neurological Exam
• Numbness: Numbness Paresthesia (q.19) Absent compared to Present
• Spontaneous Neuropathic Qualities: Burning Sensation (q.16), Stabbing Sensation (q.17), Tingling Sensation (q.18), or Numbness Paresthesia (q.19) compared to None
• Induced Pain: Hyperalgesia (q.23) or Allodynia (q.24) compared to Neither
• Hyperalgesia: Hyperalgesia (q.23) Absent compared to Present
• Allodynia: Allodynia (q.24) Absent compared to Present
• Induced Pain AND Numbness: Hyperalgesia (q.23) or Allodynia (q.24) AND Numbness Paresthesia (q.19) compared to Other

Post-Traumatic Neuropathy Assessment
• Location of pain diagram (Neuropathic Pain, q.3) compared to location of pain diagram (Physical Exam Abnormal Sensation Pinprick, q.7)
• Physical Exam Abnormal Sensation, Pinprick (q.7): Yes (increased or decreased) compared to No
• Physical Exam Abnormal Sensation, Allodynia (q.9): Yes compared to No
• Location of pain diagram (Neuropathic Pain, q.3) compared to location of pain diagram (Physical Exam Abnormal Sensation Allodynia, q.9)
• Physical Exam Abnormal Sensation, Pinprick (q.7) AND Physical Exam Abnormal Sensation, Allodynia (q.9) compared to Other
• Physical Exam Abnormal Sensation, Cold (q.8): Yes (increased or decreased) compared to No
• Physical Exam Abnormal Sensation, Cold (q.8) AND Physical Exam Abnormal Sensation, Allodynia (q.9) compared to Other
• Location of pain diagram (Neuropathic Pain, q.3) compared to location of pain diagram (Physical Exam Abnormal Sensation Injured Area, q.10) Yes and No

PainDetect
• Total PainDetect score

Requested Studies:

A Randomized Double Blind Placebo Controlled Parallel Group Study Of The Efficacy And Safety Of Pregabalin (Bid) In Subjects With Post-traumatic Peripheral Neuropathic Pain
Sponsor: Pfizer, Inc.
Study ID: NCT01701362

Public Disclosure:

Gewandter JS, Sohn MB, De Guzman R, Frazer ME, Chiodo V, Sharma S, Geha P, Markman JD. Predicting treatment response with sensory phenotyping in post-traumatic neuropathic pain. Pain Med. 2022 Mar 21:pnac045. doi: 10.1093/pm/pnac045. PMID: 35312012.