The pathophysiology of otitic hydrocephalus.

The pathophysiology of otitic hydrocephalus remains controversial. It has been argued that involvement of the superior sagittal sinus, by, at least, a mural thrombus is a necessary component of this disease. We present a case of otitic hydrocephalus where on magnetic resonance imaging (MRI) normal luminal and mural flow within the superior sagittal sinus is demonstrated. The presence of thrombus in the lateral venous sinus alone appears sufficient in this case to impede venous drainage of the intracranial contents into the neck and produce a rise in the cerebral venous pressure and a subsequent increase in the CSF pressure. The presence of a superior sagittal sinus mural thrombus is not required.