Below is a summary of our research presented May 19-21, 2011, at the 30th Annual Scientific Meeting of the American Pain Society, Austin, Texas. The study was done jointly by Dr. Campa and Dr. Larison over the last three years. Both physicians were on-site to present our findings. This research should help other physicians more accurately diagnose and treat those patients who present with mid back pain, that may involve contact with the spinal cord.
John A. Campa III, MD
Tom C. Larison, DC
July 31, 2011
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The Usefulness Of Somato Sensory Evoked Potentials in the Diagnosis of Persistent Thoracic Pain and Extrinsic Myelopathy
J. A. Campa III, MD, T. C. Larison, DC, Pain Diagnosis Consultants, LLC, Albuquerque, NM; Faculty, School of Medicine, University of New Mexico, Albuquerque, NM.
INTRODUCTION:
Persistent mid back pain presents a special challenge to the diagnostician, as both intrinsic- and extrinsic medullary etiologies must be considered. The upper and lower extremity Somato Sensory Evoked Potentials studies (SSEP), in their functional assessment of the relevant spinal segmental levels C4-5/N9-N13 Latency (N9-N13), T11-12/T12 Latency (T12) and L3-4/L3-P37 (L3-P37) would assist in resolving the primary pain generator, especially when correlated with EMG and neuroimaging findings.
AIM:
The goal of this study is to assess the value of SSEP in the diagnosis of patients with persistent mid back pain, particularly in the presence of potential extrinsic, medullary pain generators.
METHODS:
A 30-month retrospective chart review was performed; 13 patients underwent SSEP, excluding those with intrinsic spinal cord lesions at the site of mid back pain; Results were correlated with clinical findings, paraspinal thoracic EMG and CT, MRI lesions between T1 and T12 (cord contact or impingement, calcific nodules posterior to cord, disc bulge-degeneration-herniation-protrusion, vertebral anterior wedging). Positive study criteria were: mid back pain, prolonged L3-P37 latency, normal N9-N13 latency, normal T12 latency.
RESULTS:
Results revealed the following - Positive SSEP: 11/13 (84.6%); Positive SSEP, with correlating neuroimaging: 9/11 (81.8%); Positive SSEP, without correlating neuroimaging: 2/11 (18.2%); Positive SSEP, with correlating neuroimaging and EMG: 7/11 (63.6%); Negative SSEP: 2/13 (15.4%); EMG findings: 7/7 chronic polyphasia-reinnervation; 2/7 acute fibrillation potentials;
CONCLUSIONS:
We conclude that the SSEP is a valuable diagnostic tool in the assessment of persistent mid back pain. We recommend its routine use in the evaluation of thoracic pain, particularly in patients with known thoracic spinal segmental lesions.
