Complications of lumbar puncture followed by anticoagulation.

The complications associated with lumbar puncture (LP) were compared in 2 groups of 342 patients. The first group of patients was anticoagulated after the LP, and the second was not. The incidence of minor headache or back pain was similar in the 2 groups (Group 1--62%, Group 2--64%). The anticoagulated patients had a higher incidence of paraparesis (Group 1, 5 patients, Group 2, No patients; p less than .05) and severe back or lumbosacral radicular pain lasting more than 48 hours (Group 1, 18 patients, Group 2, 6 patients; p less than .025). Seven of the anticoagulated patients developed spinal hematomas (5 with paraparesis, 2 with severe back pain). Among the anticoagulated patients the risk of a major complication was increased by a traumatic LP (p less than .001), starting anticoagulation within one hour of the LP (p less than .001), or aspirin treatment at the time of the LP (p less than .001). This study suggests that if LP is done, delaying anticoagulation for at least one hour and avoiding concurrent aspirin therapy may decrease the risk of developing an extraparenchymal spinal hematoma.