The success rate of spinal tap procedures, or lumbar punctures, is very high, and the procedure is generally considered safe. However, up to 25 percent of patients experience some mild complications, states Mayo Clinic. The most common complication is post-dural puncture headache, or PDPH, according to an article in Neurology.
A survey of lumbar puncture patients indicated that 3.8 percent experienced backache and 3 percent experienced other headache symptoms, reports Neurology. Six percent of the surveyed patients experienced other types of complications. The PDPH can begin between two hours and two days following the spinal tap, and it can continue from a few hours to a week or longer, according to Mayo Clinic.