An arachnoid bleb and weeping dura-a persistent low flow CSF-leak after lumbar puncture

Post-dural puncture headache (PDPH) is a well-recognized and frequently encountered complaint of Lumbar puncture. It usually resolves spontaneously over two weeks or with an epidural blood patch. Although known for a long time, PPDH could be linked to an arachnoidal bleb as a cause of cerebrospinal fluid (CSF) leakage. We report on surgical findings and impressive findings with low-flow CSF leakage in the context of an arachnoidal bleb.

We report a 42-year-old Neuroscientist with a 23-month history of positional headaches after a lumbar puncture (LP). Multiple Sclerosis was ruled out, but chronic orthostatic headache and tinnitus developed. Bed rest, caffeine tablets, IV hydration, and five high-volume epidural blood patches did not lead to improvement. However, brain fog and reduced ability to work ensued. A dynamic myelography did not reveal a CSF leak or a CSF-venous fistula, but a high-resolution T2Space Fat-saturated MRI detected an arachnoidal bleb at the alleged L3-L4 level. Microsurgical exploration identified the arachnoid bleb as a low-flow CSF leak. The video depicts Neomenbranes overlaying the dura mater appearing as a web and CSF oozing, washing a layer of blood away. CSF was leaking like a tear, and we had the impression of a weeping dura. Treatment involved bipolar shrinking, reinforcement of the dura and fibrin glue. The patient's symptoms improved slowly post-surgery.

This case emphasises the importance of considering atypical causes of post-lumbar puncture complications, such as arachnoid blebs, and the role of surgery in identifying and treating these rare conditions.