A Prospective, Masked 18-Month Minimum Follow-up On Neurophysiologic Changes In Persons with Spinal Stenosis, Low Back Pain, and No Symptoms
Objectives
To describe neurophysiologic changes over time in persons with and without spinal complaints and to assess whether paraspinal denervation predicts change in stenosis on magnetic resonance imaging (MRI) and clinical course.
Design
Prospective, controlled, masked trial.
Setting
University spine program.
Participants
Persons aged 55 to 80 years, screened for polyneuropathy and determined on clinical examination to have spinal stenosis, mechanical low back pain, or no spinal symptoms.
Interventions
A comprehensive codified history was obtained and subjects underwent physical examination, ambulation testing, masked electrodiagnostic testing including paraspinal mapping, and MRI, repeated at greater than 18 months. This study presents detailed technical information and additional analyses not reported previously.
Main Outcome Measurements
Change in electrodiagnostic findings. Among persons with clinical stenosis, relationship of change in paraspinal mapping scores to MRI findings and clinical changes.
Results
Of 149 initial subjects, 83 (79.3% of eligible subjects) repeated testing at 20 (±2 SDs) months. No significant change in limb muscle spontaneous activity or motor unit pathology was noted in any group. In 23 persons with initial diagnosis of stenosis, paraspinal mapping electromyography related to change in diagnosis over time (analysis of variance F = 3.77, P = .037), but not to most initial magnetic resonance imaging measurements or to change in spinal canal diameter.
Conclusions
Clinical spinal stenosis is neurophysiologically stable in most persons. Paraspinal electromyographic changes reflect large changes in clinical course, but neither neurophysiologic nor clinical changes relate to change in spinal geometry over 20 months.
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Disclosure Key can be found on the Table of Contents and at www.pmrjournal.org
This is a publication of the Spine Program of the University of Michigan, which is funded by the U.S. Department of Health and Human Services, National Institutes of Health, under Grant 5 R01 NS41855-02. The opinions contained in this publication are those of the grantee and do not necessarily reflect those of the U.S. Department of Health and Human Services. The funding source had no role in any of the following: the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript.
PII: S1934-1482(08)00020-8
doi:10.1016/j.pmrj.2008.10.007
© 2009 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.