A 71-year-old woman was losing the ability to walk steadily and to think clearly. In an older adult, that pattern usually points toward dementia or an untreatable degenerative disease. Hers turned out to be something a surgeon could fix in a single operation.
Neurosurgeons and neurologists in Japan reported in Surgical Neurology International in 2026 that the cause was a giant fluid-filled cyst in the quadrigeminal cistern, pressing on the midbrain and blocking the narrow channel that drains spinal fluid out of the brain. Surgeons opened the cyst through a right frontal burr hole using an endoscope, creating a communication with the third ventricle.
