Answer of January 2009

Clinical History:

A 40-year-old lady who enjoyed good past health was admitted due to sudden onset of headache associated with repeated vomiting. She had no history of trauma or back pain. The headache was aggravated by erect position and relieved after lying down. On physical examination, no focal neurological deficit is observed.
MRI brain was obtained.

T2 Axial

T1 axial + Contrast

T1 Sagittal + Contrast

Diagnosis:

Spontaneous intracranial hypotension

Discussion:

The 5 characteristic imaging features of spontaneous intracranial hypotension visible on MRI are (1) subdural fluid collections, (2) enhancement of the pachymeninges, (3) engorgement of venous structures, (4) pituitary hyperemia, and (5) sagging of the brain (mnemonic: SEEPS) that could be evidenced by downward displacement of cerebellar tonsils, bowing of optic chiasma, obliteration of basal cistern and flattening of pons against the clivus. The principal symptom of SIH is headaches. The headaches are typically positional, only occur when the patient is upright, and gradually disappear when the patient is lying down. In most cases, the headaches gradually increase from the moment the patient wakes up in the morning. However, in other cases the headaches are quick and severe. Some of the related symptoms of SIH are a loss of hearing, tinnitus, vertigo, stiffness of the neck, nausea, and even vomiting The precise cause of spontaneous spinal CSF leaks remains largely unknown, but an underlying structural weakness of the spinal meninges generally is suspected. A history of a more or less trivial traumatic event preceding the onset of symptoms can be elicited in about one third of patients, suggesting a role for mechanical factors as well. There is good evidence to suggest that a generalized connective tissue disorder plays a crucial role in the development of spontaneous spinal CSF leaks. Based on physical examination alone, evidence for an underlying generalized connective tissue disorder is found in about two thirds of patients. The condition is generally benign and self-limited, but some patients require treatment of associated subdural hematoma or of persistent headache. Conservative symptoms include bed rest, oral hydration, generous caffeine intake, glucocorticoid medication, or mineralocorticoid agents. The mainstay of treatment for persistent spontaneous intracranial hypotension is the placement of lumbar epidural blood patches. If the patient fails to respond to this therapy, direct epidural blood patch, percutaneous placement of fibrin sealant or surgical repair would be considered and localization of exact site of CSF leak could be done by CT or MR myelography.