Physicians may extract a sample of cerebrospinal fluid when

Physicians may extract a sample of cerebrospinal fluid when they suspect an infection in the brain. Where is the least risky and least difficult place for them to insert a needle through the meninges?

Solution

Cisternal taps are easier to perform and have less risk of iatrogenic hemorrhage compared to lumbar taps because lumbar taps are technically difficult to perform due to anatomy and a small interarcuate space.This subarachnoid space is so small that it makes more difficult to spot the needle at the extract location to collect the CSF(Cerrebrospinal fluid).But in cisternal tap there is very less risk due to proximity to the brainsteam and cerebellum.The cerebellomedullary cistern is very easy technique for collecting the CSF.There are also risk in cisternal tap as due to intracranial pressure due to intracranial disease due to a pressure differential created through the spinal needle but there are some cautions that is made to avoid all thse risks.Lumbar tap is much more riskier as it has higher chance for iatrogenic hemorrhage which is a very difficult thing to solve out later.