Intrathecal bupivacaine protects against extension of lesions in an acute contusive spinal cord injury model.
OBJECTIVE
We recently demonstrated that intrathecal bupivacaine before or after acute photochemical spinal injury improved functional outcome in rats. However, the closest model to spinal trauma is the contusive weight-drop method. The aim of this study was to evaluate functional, electrophysiological and anatomical consequences of a contusive spinal-cord lesion in rats with or without an intrathecal injection of bupivacaine.


METHODS
Fifteen minutes before a contusive spinal lesion, 18 rats received intrathecally either 0.5% bupivacaine (Group T) or saline (Group C). During an 18-days period, motor and sensory functions were evaluated, and bladder voiding dysfunction was noted. Somatosensory evoked potential testings were performed at day 18. Then, the intact spinal cord area at the epicentre of the lesion and the extent of the lesion were measured.


RESULTS
Motor deficit was less and inclined-plane stability was better in treated animals at all times, the scores were statistically different from day 7. There were no differences concerning the sensory test. Despite no significant difference, there were less spinal bladders in the T group from day 7. Somatosensory evoked potential latencies were longer in T group, but only the first negative component (N1) was statistically significant. Amplitudes were higher in T group, but were not statistically different. The spinal cord intact area at the epicentre of the lesion was higher in the T group (1.23 +/- 0.8 mm(2) vs. 0.81 +/- 0.39 mm(2); P < 0.05). The extent of the lesion was higher in the C group (9.4 +/- 2.9 mm vs. 6.4 +/- 3.4 mm; P < 0.05).


CONCLUSIONS
Intrathecal 0.5% bupivacaine provide a neuroprotective effect by decreasing functional, electrophysiological and anatomical consequences after a contusive spinal cord injury.
Lopez
S
S
Lapeyronie University Hospital and EA 701, Department of Anesthesiology and Critical Care Medicine, Montpellier School of Medicine, France.
Dadure
C
C
Vergnes
C
C
Capdevila
X
X
D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000494:pharmacology; D000818:Animals; D002045:Bupivacaine / Q000008:administration & dosage* / Q000494:pharmacology; D004333:Drug Administration Routes; D004594:Electrophysiology; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects*; D007278:Injections, Spinal; D008297:Male; D018696:Neuroprotective Agents / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000188:drug therapy; D013997:Time Factors; D016896:Treatment Outcome
D000779:Anesthetics, Local; D018696:Neuroprotective Agents; D002045:Bupivacaine