Sudden intraaqueductal dislocation of a third ventricle ependymoma causing acute decompensation of hydrocephalus.

The authors report an unusual sudden intraaqueductal dislocation of a third ventricle ependymoma causing acute loss of consciousness, and they detail its neuroendoscopic treatment. This case is unique and has never been described in the literature before. The patient suffered from headache and recurrent nausea. Admission MR images revealed a contrast-enhancing lesion within the posterior part of the third ventricle. During the course of the day of admission, the patient suddenly became comatose. Emergency MR imaging demonstrated a deeply intraaqueductal dislocation of the pedicled tumor, with complete obstruction of the aqueduct and ventricular dilation. Immediate surgical intervention with endoscopic third ventriculostomy and complete tumor removal was performed. After surgery, the patient made a rapid recovery. In this case, the authors presume a sudden intraaqueductal dislocation of the ependymoma caused by aspiration of the tumor as a result of the caudal CSF flow.