"Brain herniation into arachnoid granulation (BHAG) is an imaging finding with unknown significance that may result from brain herniation into arachnoid granulations in the calvarium or venous structures, including the dural venous sinuses, diploic veins, or meningeal veins 1."
Expected headings
"Associations"
"BHAGs are usually incidental findings; however, headaches, dizziness, imbalance, and ear pressure have been described in patients with herniations into the transverse sinus 1,2. Epilepsy could potentially result from temporal lobe herniation and could be occult. CSF otorrhoea occurred in one case due to erosion of a petrous bone 3."
"BHAGs occur in adults at common sites of arachnoid granulations and are bathed in CSF 2; these findings led to the proposal that brain herniates into arachnoid granulations. A large series 2 showed that the BHAGs at the dural sinuses, particularly the transverse sinus, were the most common, while calvarial BHAGs were much less common."