Otogenic Intracranial Inflammations: Role of Magnetic Resonance Imaging

Abstract

The clinical course of acute otitis media is usually short, and the process terminates because of the host's immune system, the infection-resistant properties of the mucosal linings, and the susceptibility of the major organisms (beta-hemolytic streptococcus or pneumococcus) to penicillin. However, a small proportion (1% to 5%) of untreated or inadequately treated patients may experience complications. Prior to the development of an intracranial complication of otomastoiditis, warning symptoms or signs may be evident; these include severe earache, severe headache, vertigo, chills and fever, and meningeal symptoms and signs. Increasing headache, particularly temporoparietal headache near the affected ear, often indicates an impending intracranial complication. This symptom, often the only indication of an epidural abscess, demands prompt investigation and medical and surgical intervention. In our experience, computed tomography (CT) permits accurate diagnosis of acute coalescent or latent (masked) mastoiditis and its associated complications. However, magnetic resonance imaging (MRI) remains the study of choice to evaluate otogenic intracranial complications. This article demonstrates the important role of MRI in diagnosing various stages of acute otomastoiditis and its associated complications.

Otogenic Intracranial Abscesses, Our Experience Over the Last Four Decades

“…Brain CT is widely available nowadays and is often used in the initial diagnostics for neurological conditions; nowadays, it may also be used for patients with otogenic IAs [27] . When otogenic infection is suspected, a CT scan of the ear is often performed because CT is efficient in evaluating bony structures [28,29] . Additionally, MRI has proved valuable for locating otitic intracranial or extracranial complications [28] .…”

“…When otogenic infection is suspected, a CT scan of the ear is often performed because CT is efficient in evaluating bony structures [28,29] . Additionally, MRI has proved valuable for locating otitic intracranial or extracranial complications [28] .…”

MR Imaging Features of Acute Mastoiditis and Their Clinical Relevance

“…In the context of AM, evidence indicates the superiority of MR imaging over CT in the detection of labyrinth involvement and intracranial infection. 1,6,14 Little focus has, however, been on intratemporal MR imaging findings, with most reports only of intramastoid high signal intensity on T2WI, reflecting fluid retention-a finding evidently nonspecific and leading to mastoiditis overdiagnosis. 10,11 During mastoiditis, variable signal intensities of retained fluid and intratemporal enhancement can appear, explained by desiccation of fluids and overgrowth of granulation tissue, especially under chronic conditions.…”

“…While the usefulness of MR imaging in diagnosing intracranial AM spread has been demonstrated many times over, 1,[5][6][7][8][9] intratemporal findings of AM on MR imaging tend to be overlooked and information on their clinical relevance is scarce. Problems exist with overdiagnosing "mastoiditis" on MR imaging if it is based on intramastoid fluid signal alone.…”

Complications of acute otitis media in children

“…CT scan of the brain and temporal bones with intravenous contrast is recommended as the primary radiologic examination for the evaluation of otogenic intracranial complications [28•]. However, MRI often gives further information for the evaluation of otogenic intracranial complications [39]. CT scan gives information on the bony structures of the mastoid and middle ear, and on the invasion of the infection.…”