The visualized major intracranial vessels appear patent. No definite abnormality is seen in the visualized portions of the orbits. The middle ear cavities, mastoid air cells, and paranasal sinuses are clear. IMPRESSION: Worsening hydrocephalus with an interval increase in size of the entire ventricular system as well as an increase in size of a suboccipital pseudomeningocele. The dilated anterior recess of the third ventricle has some mass effect on the optic chiasm, which could play an etiological role in the patient's visual signs.