Considering the invasiveness of the procedure, most lumbar puncture complications are infrequent. The most common complication is a headache, which occurs in about four out of ten lumbar puncture patients and is usually resolved within one week. Other complications are more serious but occur with much less frequency. Meningitis, nerve root injury, and prolonged backache are among the possible, although rare, lumbar puncture complications.
The headache that occurs after a lumbar puncture is called a postdural puncture headache. Its causes are not known. It occurs more often in women than in men and less often in both younger and elderly patients. Several studies show that the choice of needle used for the lumbar puncture affects the incidence of these types of lumbar puncture complications. Pencil-point needles, as opposed to bevel-point needles, appear to significantly reduce the occurrence of postdural puncture headaches.
Studies show that neither bed rest nor remaining prone for an extended period of time prevent a postdural puncture headache. Oral caffeine provides some transient relief, but it is short acting and will not eliminate the headache. The most effective treatment is an epidural blood patch. The patch is applied postpuncture and provides relief for up to 98 percent of patients experiencing a postdural puncture headache.
Serious lumbar puncture complications include tonsillar herniation, intracranial bleeding, and infections. These types of complications are rare. Some complications occur more frequently in patients whose health or condition is compromised. Patients with serious existing medical conditions are more prone to develop dangerous complications as a result of lumbar punctures.
Samples of cerebrospinal fluid are obtained from a lumbar puncture. This fluid surrounds the brain and spinal cord. Examination of the fluid can help diagnose diseases such as meningitis, multiple sclerosis, and cerebral hemorrhage. The procedure is sometimes preformed in order to determine changes in the cerebrospinal pressure. The difference in pressure prior to fluid removal and after fluid removal can assist in the diagnosis of a brain tumor or infection.
Neurologists or other trained medical personnel perform lumbar punctures. The procedure usually takes place on the lower back. Doctors first clean, sterilize, and sometimes anesthetize the area around the site chosen for the puncture. They insert a needle between the vertebrae and move into the space filled with cerebrospinal fluid. Once the fluid is withdrawn, doctors remove the needle and cover the puncture with a sterile dressing.