Is There Reasonable Evidence to Discard Mandatory Brain Imaging in Acute Mastoiditis? Literature Review and Meta-analysis

Introduction: Acute mastoiditis (AM) related intra-cranial complications (ICC) are prevalent and should be diagnosed and treated promptly. Infectious ICC are diagnosed using brain imaging and may be missed without it. Nevertheless most clinicians base their decision to perform brain imaging on clinical suspicious only. The aim of the study was to determine whether there is an association between rate of imaging performance and the diagnosis of ICC in AM.

Methods: Google scholar, PubMed, Medline, EMBASE, Web of science and Cochrane websites were searched from 1992 to 2017 (last search conducted on November 2017) using the key words: acute mastoiditis, otomastoiditis, imaging and intracranial complications in English only with no restrictions regarding age of patients.

Results: The database search yielded 1071 studies. 61 studies were found to be suitable for the meta-analysis. The rates of ICC were found to be significantly higher in centers where brain imaging was mandatory done, as compared to centers where brain imaging was performed ‘as needed’, based on clinical presentation. A typical clinical combination on which centers based their indication for imaging in AM patients was hard to elucidate.

Conclusions: Available publications (up to 2017) do not offer high grade clinical evidence based measures for defining the AM patient who is at a high risk for developing ICC. ICC are under-diagnosed in centers where brain imaging is performed in the minority (<50%) of AM patients, based on ad hoc clinical judgment only.