Report an error   


Submitted: 16 May 2007
HERDIN Record #: PCHRDPC040361

Somatosensory evoked responses during cerebral ischemia in the rabbit.

 Eduardo, Emmanuel,
 Espiritu, Ma. Gerald,
 Saniel, Edmundo,
 Damian, Ludwig

See More

BACKGROUND: Somatosensory evoked potentials (SSEP) are the electrical potentials generated in sensory pathways at the peripheral, spinal, subcortical (thalamic) and cortical level. It is mainly used for intraoperative monitoring of the spine. It has a role in intraoperative monitoring where there is a risk of developing cerebral infarction as a result of decreased perfusion or temporary loss of cerebral blood flow
HYPOTHESIS: Somatosensory evoked potentials can detect cerebral infarction and changes related to cerebral perfusion
OBJECTIVE: 1) To determine real time SSEP response to ischemia; 2) to correlate SSEP changes with duration of carotid ligation; 3) to predict reversibility of ischemia by using SSEP measurements
SPECIFIC: To define the actual time where potentials are completely lost and clinical damage sets in, and to determine actual SSEP amplitude decrement that would produce clinical and electrophysiologic deficit
DESIGN AND METHODOLOGY: Prospective animal study using rabbits divided into 2 groups: first to assess the critical duration of carotid occlusion and the 2nd to determine the critical amplitude decrement that would produce reversible clinical and electrophysiologic measurements. This is achieved by measuring cortical SSEP before, during, and after occlusion of the left common carotid artery. Neurologic function after 0, 3, and 48 hrs of surgery is measured and correlated
RESULTS: 9 rabbits were subjected to the procedure and all had SSEP measurements taken and recorded. 6 rabbits in group one had absence of SSEP after 1 min. of complete occlusion. SSEP failed to recover after 60 min. of carotid occlusion and clinical deficits were noted at 45 to 60 min. occlusion The 3 rabbits in group 2, all occluded for 60 minutes showed that a reduction of 70-100 percent from baseline is the critical amplitude level where there is permanent clinical and electrophysiologic damage
CONCLUSION: SSEP can detect changes in CBF as early as 1 minute. Sixty minutes of occlusion and 70 percent amplitude reduction correlated with persistent SSEP and clinical deficits. SSEP is a good indicator of cerebral hypoperfusion and can predict reversibility of cerebral ischemia. (Author)

Publication Type
Journal
Title
The Philippine Journal of Neurology
Frequency
2002 Jun
Publication Date
Page(s)
0
LocationLocation CodeAvailable FormatAvailability
Philippine Council for Health Research and Development Library Abstract Print Format (Request Document)

Copyright © One Window Project 2018. All rights reserved.