cerebrospinal fluid otorrhea.
, especially large ones within the transverse and sigmoid sinuses, are also calcified in middle-aged and older people with characteristic appearances.
Communicating hydrocephalus is caused by diminished resorption of CSF at the arachnoid granulations
, leading to an expansion of both the ventricular system and the subarachnoid space.
The differential diagnosis includes giant arachnoid granulations
(mimicking a filling defect in the sinus) and a congenitally hypoplastic transverse sinus.
Transependymal drainage of CSF, followed by medullary venous drainage, supervenes as arachnoid granulations
are not fully matured in the neonate.