What is spontaneous intracranial hypotension ?
Spontaneous intracranial hypotension is a disease characterized by orthstatic headache.Orthostatic headache is a headache induced or aggravated by standing up in about 15 minutes and resolved by lying down in about 15 to 30 minutes.
What is orthostatic headache?
Orthostatic headache is a headache induced or aggravated by standing up in about 15 minutes and resolved by lying down in about 15 to 30 minutes.
What is the mechanism of headache in spontaneous intracranial hypotension ?
– Decreased buoyancy which caused by CSF leakage makes brain migrates to downward producing headache.
– The downward migration of brain pulls down dura mater which is very sensitive to pain.
– On lumbar puncture CSF pressure is measured lower than 60mmH2O, mostly are lower than 30mmH2O
What is MRI findings of Spontaneous intracranial hypotension?
MRI
– Subdural fluid collection (50%), mostly subdural hygroma
– Diffuse dural enhancement
– Downward migration of brain ± ventricular collapse
– Hyperemia of pituitary gland
Note that optic chiasma shows downward migration just above the pituitary gland (probably due to diminished CSF between them).
Right) Normal patient shows high signal CSF around optic chiasm.
