Labyrinthitis Ossificans

Abstract

Labyrinthine ossificans is defined as pathologic new bone formation within the otic capsule in response to an inflammatory and/or destructive process. Although the cause is multifactorial in most cases, most extensive disease is seen in postmeningitic cases, with the scala tympani of the basal turn being the most common region of cochlear ossification (1). Causes of ossification include trauma, malignant infiltration, otosclerosis, allergy, and infections reaching the inner ear via hematogenous, meningitic, or tympanic routes (2).Ossification in the inner ear is a well-documented sequela of suppurative labyrinthitis. Paparella and Sugiura (3) outlined the histopathologic stages associated with purulent labyrinthitis and the process leading to ossification in the labyrinth of laboratory animals and humans. They divided the evolution of ossification consequent to purulent labyrinthitis into 3 stages: acute, fibrous, and stage of ossification. The acute stage is characterized by purulent effusion that fills the perilymphatic spaces but spares the endolymphatic space, followed by formation of serofibrinous precipitates. The second or fibrous stage is marked by fibroblastic proliferation within the perilymphatic space. This stage begins approximately 2 weeks after the onset of infection and is accompanied by angiogenesis. The third or stage of ossification shows new bone formation, which is first seen in the basal turn of the cochlea as early as 2 months after onset of infection.Although inner ear ossification is primarily a histopathologic diagnosis, its detection by use of complex motion tomography and computed tomographic scan is clinically relevant in patients who are candidates for cochlear implants (2).We are presenting a case with labyrinthitis ossificans with extensive ossification throughout the cochlea. The patient had a history of acoustic neuroma resection, which was complicated by meningitis in the postoperative period. The cause of ossification may be meningitis, surgical trauma, or a combination of both factors, wherein the surgical trauma provided direct access for the meningeal infection to reach the inner ear. CASE REPORTTemporal bones were obtained from a 72-year-old man who died of unknown cause. This patient had undergone resection of an acoustic neuroma on the right side via a translabyrinthine approach at the age of 63 years. His postoperative course was complicated with meningitis, which resolved with treatment. He had progressive hearing loss in his left ear and received cochlear implantation on the left side at the age of 70 years. Details of the audiologic evaluation are not available. The patient died 2 years after implantation.Address correspondence and reprint requests to Michael M. Paparella, M.D.,

Cochlear implant after bacterial meningitis

“…Labyrinthitis ossificans, the last stage, shows new bone formation, often initiated in the basal turn. This last stage is seen as early as 2 months after the onset of meningitis and is described in up to 70% of the ears . The ossification challenges the implantation and thereby also the outcome due to the risk of only partial insertion of the electrode or even impossible insertion.…”

Predicting Parameters for Audiological Complications in Pediatric Patients Affected by Meningitis

“…Then it moves to a brous stage, between the second and third week from the onset, with granulation tissue and neoangiogenesis processes: the damage can be irreversible, but surgery is still possible. After at least two months from the onset, an ossifying stage occurs, with mineralization and obliteration of the structures of the inner ear; at this stage hearing damage is irreversible and there is no possibility of effective surgical intervention (7,13,14).…”

Etiology-Specific Mineralization Patterns in Patients with Labyrinthitis Ossificans

“…the ossification of structures within the membranous labyrinth of the inner ear, leading to sensorineural hearing loss. [1][2][3][4][5][6][7][8] There are typically 3 described phases of LO, including an acute, fibrotic, and ossifying phase. 9 Ossification has been described on histopathology as starting in the perilymph of the basal turn of the cochlea and then spreading to involve the entire inner ear.…”

“…11 A multitude of etiologies have been described as potential causes of LO, including otologic infection, infectious meningitis, inflammatory/autoimmune diseases, traumatic injury, iatrogenic injury related to a prior operation, and hematologic causes such as sickle cell disease. [1][2][3][4][5][6][11][12][13][14] Prior publications on LO comprise mostly case reports, with few studies reporting findings of observational/cross-sectional studies.…”