Reversibility of Parinaud syndrome in thalamic hemorrhage

Parinaud syndrome, associated with a left thalamic hemorrhage, disappeared completely in a 57-year-old woman after ventriculoperitoneal shunt. The syndrome may be attributed to increased intracranial pressure owing to mass effect on the pretectal region and tectum, or to tightness in the incisura causing hydrocephalus secondary to aqueduct compression. The lesions responsible for the syndrome may not be irreversible.