Document Detail

Laser Doppler study of porcine cauda equina blood flow. The effect of electrical stimulation of the rootlets during single and double site, low pressure compression of the cauda equina.
MedLine Citation:
PMID:  7604341     Owner:  NLM     Status:  MEDLINE    
STUDY DESIGN: This study involved a model of spinal claudication to assess the effect of single and double site compressions on blood flow in porcine cauda equina. Real-time monitoring of blood flow was achieved by using laser Doppler probes. OBJECTIVES: To ascertain the difference between single and double site compressions on blood flow and nerve conduction in the cauda equina. Also, to provide possible explanations for the mechanisms underlying the pathophysiology of neurogenic claudication. SUMMARY OF BACKGROUND DATA: The model used was based on that of K. Olmarker. Double as compared with single site compression of cauda equina showed impaired nerve impulse propagation and decreased blood flow. METHOD: Pigs weighing 22-27 kg were anesthesized and the cauda equina was exposed by dorsal laminectomy of the sacral and first three coccygeal vertebrae. Polyethylene balloons were placed over the rootlets at the first and third coccygeal segments, and stimulating electrodes were positioned on the rootlets proximally to evoke motor activity. Electromyographic activity was monitored from tail musculature. Laser Doppler probes monitored blood flow in the cauda equina both between and distal to the two compression sites. RESULTS: Single site, low level compression did not affect blood flow whereas double site compression decreased it profoundly. Proximal stimulation caused a marked increase in blood flow, which was not sustained during prolonged compression. Electromyographic activity diminished concomitantly during this compression. CONCLUSIONS: Low pressure, double site compression significantly reduces cauda equina blood flow and prevents the sustained increase in blood flow required to maintain normal neurologic rootlet function. Local blood flow failure may therefore be responsible for claudication symptoms.
A R Baker; T A Collins; R W Porter; C Kidd
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Spine     Volume:  20     ISSN:  0362-2436     ISO Abbreviation:  Spine     Publication Date:  1995 Mar 
Date Detail:
Created Date:  1995-08-10     Completed Date:  1995-08-10     Revised Date:  2010-03-24    
Medline Journal Info:
Nlm Unique ID:  7610646     Medline TA:  Spine (Phila Pa 1976)     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  660-4     Citation Subset:  IM    
Department of Biomedical Sciences, University of Aberdeen, Scotland.
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MeSH Terms
Blood Flow Velocity / physiology
Cauda Equina / blood supply*
Disease Models, Animal
Electric Stimulation
Laser-Doppler Flowmetry*
Spinal Cord Compression / physiopathology*
Spinal Stenosis / physiopathology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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