Evaluation and management of temporal bone arachnoid granulations.

The diagnosis and evaluation of temporal bone arachnoid granulations (AGs) is based on characteristic bone defects in the posterior or middle fossa surfaces of the temporal bone in adult patients with persistent serous otitis media or septic meningitis following acute otitis media. The cerebrospinal communication caused by AGs should be repaired by a middle fossa craniotomy (middle fossa AGs) or an intact canal wall mastoidectomy (posterior fossa AGs) to preserve normal sound transmission. In adult patients with chronic mastoiditis, the dural defect of an AG may permit intracranial extension of the chronic inflammatory process. This rare extension of disease should be considered in patients who have chronic ear inflammation and severe pain or signs of intracranial disease.