Histopathology of the Inner Ear in a Case With Recent Onset of Cogan’s Syndrome

Abstract

The association of sensorineural hearing loss and vertigo with inflammatory eye disease, usually interstitial keratitis, has been called Cogan's syndrome. The pathogenesis of Cogan's syndrome is unknown, but it has been assumed to be an immune mediated disorder with vasculitis. The histopathology of the inner ear in Cogan's syndrome has been described in 6 case reports. Although common pathologic findings in these reports include degeneration of the auditory and vestibular neuroepithelium, endolymphatic hydrops, fibrosis, and new bone formation, direct pathologic evidence of a vasculitis has not been published. A possible reason for this failure to identify vasculitis was a substantial delay (range, 4-40 years) between the onset of symptoms and examination of the otopathology. In the current case report, the patient had both auditory and vestibular symptoms and interstitial keratitis with a time delay of only 2 to 4 weeks between symptoms and death. Evidence of a vasculitis as a possible underlying etiology included H&E histopathology and anti-CD45 immunostaining of vessels both in the auditory and vestibular systems, supporting the hypothesis of a vasculitis as a mechanism in this disorder.

Histopathology of the Human Inner Ear in the Cogan Syndrome with Cochlear Implantation

“…Cogan’s syndrome is considered to be associated with inflammatory bowel disease (IBD) such as ulcerative colitis (UC) and Crohn’s disease (CD) [Scharl et al, 2010; Vavricka et al, 2015], and UC was described in the medical history of the current case. The etiology of Cogan’s syndrome has been assumed to be an autoimmune disorder with vasculitis [Kessel et al, 2014; Jung et al, 2016]. …”

“…typical and atypical types [Kessel et al, 2014; Jung et al, 2016]. Typical Cogan’s syndrome consists of non-syphilitic interstitial keratitis and audiovestibular symptoms similar to those of Ménière’s syndrome.…”

“…Cogan’s syndrome is a rare disorder characterized by inflammatory eye disease and audiovestibular symptoms thought to be of autoimmune etiology [Kessel et al, 2014; Jung et al, 2016]. It may cause bilateral sudden or rapidly progressive sensorineural hearing loss, and despite immunosuppressive therapy, profound hearing loss has been reported in 52 % of patients [Gluth et al, 2006].…”

“…Although there have been several reports of the histopathology of the inner ear in Cogan’s syndrome [Fisher and Hellstrom, 1961; Wolff et al, 1965; Zechner, 1980; Rarey et al, 1986; Schuknecht and Nadol, 1994; Ishii et al, 1995; Jung et al, 2016] to date there has been no description of the histopathology of the inner ear following cochlear implantation in Cogan’s syndrome. The temporal bones of a 64-year old patient who suffered from a bilateral onset of rapidly progressive and profound sensorineural hearing loss due to Cogan’s syndrome and who underwent bilateral cochlear implantation 19 months prior to death have been obtained by the Otopathology Laboratory of the Massachusetts Eye and Ear Infirmary.…”

Rituximab Not Effective for Hearing Loss in Cogan’s Syndrome

“…Her hearing loss stabilized but did not improve after 3 months. Given the suggestion of efficacy of rituximab in sensorineural hearing loss [1], a report of improvement with this agent in a previous patient with Cogan's syndrome who had not responded to multiple other medications [2], and recent histologic findings of small vessel vasculitis in the pathology of this disease (for which rituximab is a well-established treatment) [3], rituximab was given at a dose of 375 mg/m 2 weekly × 4 doses. At 6-month follow-up, however, her hearing had not improved and audiogram was unchanged.…”