HES Patch Versus Blood Patch

Inclusion Criteria: * Subjects older than 18 years.· * Subjects with an intracranial hypertension syndrome secondary to an epidural, spinal or lumbar puncture (and therefore presumed iatrogenic) with a sub arachnoid space or subjects with intracranial hypertension syndrome of primitive origin requiring treatment with epidural Patch · * subjects with a temporal window of sufficient quality to carry out the transcranial Doppler · * Subjects haven read the informed consent, signed and dated prior to the start of any proceedings related to the tial· * Subjects affiliated to health insurance· * Subjects having been informed of the results of a prior medical consultation Exclusion Criteria: * Subjects with a cons-indication to an epidural Patch: * blood disorders constitutional or acquired coagulation with platelets * Subjects under treatment with curative doses of antiplatelet drugs or anticoagulants * subjects under shock and / or hypovolemia * subjects under generalized sepsis or at the puncture site * any other cons-indication to performing an epidural