We report the case of a patient with postural headache. A CT scan revealed bilateral subdural hygroma. Brain MRI showed diffuse pachymeningeal enhancement. A diagnosis of intracranial hypotension was therefore made. Thoracic cerebrospinal fluid leak was proved by radionuclide cisternography and contrast myelography. Conservative medical treatment was ineffective. Two thoracic epidural blood patches with radiographic control were made. We think the blood patch is the most important element for success.