Bilateral trochlear nerve palsy subsequent to ventriculoperitoneal shunting of normal pressure hydrocephalus.

Misplacement of the ventricular catheters of shunt systems may result in shunt dysfunction or a variety of neurological symptoms. Bilateral fourth nerve palsy has not been reported thus far after shunting. Here, we describe the occurrence of this unusual neurological deficit in a patient who underwent shunting for normal pressure hydrocephalus, and demonstrate its pathoanatomical correlate.