Intracranial hypotension (IH) is a rare, still not fully understood and usually self-limited condition due to low cerebrospinal fluid (CSF) pressure. The clinical symptoms typical for IH syndrome are described. An orthostatic headache is the main clinical finding. This chapter reviews the radiological signs, which may be associated with this disorder, including brain as well as spinal findings, such as intracranial pachymeningeal enhancement, subdural effusions/collections or hemorrhage, rostral–caudal brain displacement, enlargement of the pituitary gland, spinal epidural fluid collections, and distension of the spinal epidural venous plexus. These radiological findings may be highly characteristic allowing the neuroradiologist to suggest the specific diagnosis. The imaging methods used for the diagnosis of IH and CSF leak sites, such as brain and spine MRI as well as CT and MR myelography, are discussed. The recommended radiological protocol is also presented.
After the failure of conservative and medical therapy, epidural blood patch is the treatment of choice for moderate to severe intracranial hypotension. It consists of the injection of 10–20 ml of autologous blood into the epidural space. It is effective through two mechanism of action: (a) elevating the pressure in the subarachnoid space by compressing the dura instantaneously and (b) forming a fibrinous clot that seals the dural hole.
Since intracranial hypotension may present with a variety of clinical symptoms and therefore could be often misdiagnosed, it is very important to consider this entity in the differential diagnosis when reporting the clinical neuroradiology cases. Patients misdiagnosed may be exposed to the unnecessary risk of starting treatment for diseases that mimic intracranial hypotension, including aseptic meningitis or pituitary disorders; therefore, every specialist in radiology should know and properly recognize this condition.
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