We report a case of idiopathic
intracranial hypotension, a clinically rare syndrome. A 28-year-old woman was admitted with
orthostatic headaches associated with
nausea secondary to
intracranial hypotension. Lumbar puncture yielded an opening pressure of 4 cmH2O in the lateral recumbent position, and the spinal fluid
protein concentration was 56 mg/dl. There was no history of lumbar puncture or clear history of
head trauma before the onset of symptoms. Spinal and cranial MRI showed no evidence of CSF leakage, and there was diffuse meningeal enhancement following
gadolinium infusion. Cranial MRI showed no evidence of brain displacement due to low CSF pressure, such as
tonsillar herniation.
Radioisotope cisternography (RIC) showed rapid accumulation of
isotope within the bladder and early disappearance of radioactivity from the head. About 2 months later the
headaches resolved spontaneously, and repeated lumbar puncture yielded opening pressure elevation to 10.5 cmH2O with a decrease in
protein concentration to 28 mg/dl. The abnormal MRI and RIC findings had become normal. On the other hand, the patient had a low blood concentration of
vitamin A, which is thought to play some role in the production of CSF. The results of RIC suggested that the patient may have become symptomatic because of undetectable CSF leakage or hyperabsorption, but diminished production of CSF due to lower blood
vitamin A concentrations may also have been
a factor predisposing to this syndrome.