Post dural puncture headache (PDPH) is a potential complication following neuraxial procedures when the dura is punctured and entry into the subarachnoid space permits drainage of cerebrospinal fluid (CSF). In the case of lumbar punctures (LP) and lumbar drains, this is intentional to drain CSF and measure intraspinal pressure. In epidurals where the entry needle should stop outside of the dura (hence “epi-dural”), a 17 gauge dural puncture is an unintentional complication (although “dry taps” with a spinal needle are sometimes used).
I remember most of the patient risk factors for PDPH as: “a young, thin, pregnant, adult woman.” Procedure-related factors include the use of a large, sharp, cutting tip with the bevel oriented perpendicular to the cephalad-caudad axis of the spine (a non-issue with pencil-point needles).
Most patients present with a frontal or occipital headache that is classically worse in the upright position and alleviated by laying supine. Sometimes, patients can also complain of visual changes, neck stiffness, nausea, and dizziness.
So why does this happen? Most of the mechanisms hinge on CSF leakage leading to low CSF pressure. Remember the CSF circulates in continuity between the brain and spinal cord. Normally, the brain is buoyant in its CSF surroundings, but with lower pressure, cranial structures may get stretched leading to activation of nociceptive receptors and acute meningeal venous distention.
For this reason, conservative treatment measures include hydration, caffeine, oral/IV analgesics like scheduled Tylenol and Motrin around-the-clock, Fioricet, and hydrocortisone. An epidural blood patch (EBP) can be offered 24-48 hours after the inciting event to increase the lumbar (and by direct communication, the intracranial) CSF pressure.