I understand that performing a LP on a pt with elevated ICP can cause a tonsillar herniation, however, I only understand this because that is what my notes tell me. Can anybody explain the pathophysiology behind this? Thanks.
How does an LP cause a tonsillar herniation?
- Thread starter bassfishindoc
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Closed system with high pressure inside....you release the pressure from one end only....the other end pushes down due to pressure difference.
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What he said.
The assumption in saying that it can cause a herniation is that there is increased pressure. This is not always the case, but in instances of a cerebral mass, bleed, swelling, or hydrocephalus you may have increased pressure at the top - leading to downward push as you open the bottom.
Pretty rare occurrence as I understand it, but is a lot of the justification that people use for ordering a CT before an LP if they are concerned about a mass-occupying lesion.
The assumption in saying that it can cause a herniation is that there is increased pressure. This is not always the case, but in instances of a cerebral mass, bleed, swelling, or hydrocephalus you may have increased pressure at the top - leading to downward push as you open the bottom.
Pretty rare occurrence as I understand it, but is a lot of the justification that people use for ordering a CT before an LP if they are concerned about a mass-occupying lesion.
