Intracranial hypotension results from leakage and/or hypotension of cerebrospinal fluid. It can be spontaneous or secondary to a dural puncture complicating perimedullary anesthesia or a lumbar puncture. The incidence remains low with less than 1% post spinal puncture (25 gauge needle), but is observed more frequently following a lumbar puncture, up to 36% with a 20 or 22 gauge needle. Accidental puncture of the dura mater with a 17 gauge needle used for epidural anesthesia is associated with postpuncture headaches in 75-80% of cases. Classically, symptoms appear 24 to 48 hours after the puncture and consist of very intense, postural, fronto-occipital headaches which may be associated with cranial nerve symptoms such as visual or hearing disturbances or vertigo. Among the risk factors are the size and type of the needle, age under 60 and female gender. About 90% of PDPH are self-limiting within 7-10 days.

Inclusion Criteria:

• Major subject (≥18 years old)
• Subject having benefited from a bloodpatch between 01/01/2021 and 12/31/2022

Exclusion Criteria:

- Subject (and/or their legal representative if applicable) having expressed their (their) opposition to the reuse of their data for scientific research purposes

Major subject (≥18 years old) having benefited from a bloodpatch between 01/01/2021 and 12/31/2022