The condition may be frustrating to diagnose even when strongly suspected, particularly in the less dramatic cases. Brain MRI with injected contrast dye may reveal "enhancement" of the meninges lining of the brain and sometimes indicate evidence of the brain "sagging" downward from the skull toward the neck. MRI of the neck and back occasionally reveals spinal fluid leaking out of its normal location.

CT myelogram (a CT scan of the back after dye is injected into the spinal fluid) may reveal the site of the leak directly. CSF cisternogram-a procedure where a radioactive dye is injected in the spinal fluid and detected by a special radiation-detecting camera-may reveal the leak directly, or may only show indirect evidence of the leak’s presence but not its exact location.

Lumbar puncture (spinal tap) may reveal lower than normal spinal fluid pressure, and might potentially increase the severity of the symptoms temporarily. Sometimes we are 100 percent sure that there is a leak lurking somewhere, but may be unable to find it with any test.