Echographic correlation of optic nerve sheath size and cerebrospinal fluid pressure

A 23-year-old obese woman presented with papilledema. Computed tomography showed no intracranial mass lesions and lumbar puncture revealed an increased opening pressure, confirming the diagnosis of pseudo-tumor cerebri. Standardized echography of the optic nerves was performed immediately before and after lumbar puncture. A marked reduction of cerebrospinal fluid pressure correlated with a decrease in the subarachnoid fluid of the optic nerve sheath.