Progress of sensorineural hearing loss after closed head injury: presence of autoantibodies

Abstract

Sensorineural hearing impairment is a common sequel to closed head injury (CHI). In most cases, the impairment subsides within the first post‐traumatic year; in some cases the impairment is permanent and in other cases there will be progress. In most cases the reason for progress is unknown. Substantial research has been carried out to ascertain the aetiology of sudden sensorineural hearing loss (SNHL) and Menière's disease. A number of studies have demonstrated the presence of antibodies against HSP 70 antigen in patients' sera. In accordance with this finding, autoimmunity as an aetiological factor for progressive SNHL has been proposed. There are reports indicating that trauma is a possible mechanism for eliciting an autoimmune response, and the aim of the present study is to study this mechanism. The question of sympathetic cochleolabyrinthitis is highlighted. Sera from 35 subjects with a history of closed head injury three to 13 years prior to the investigation were obtained for Western blot immunoassay in an attempt to identify HSP 70 antibodies. Twenty‐seven of the subjects demonstrated progress of a sensorineural hearing impairment after CHI. Two of 35, both with progress of a SNHL, demonstrated presence of anti‐HSP 70 antibodies. Therefore, a significant role of an HSP 70 related autoimmune mechanism for SNHL progress post CHI could not be confirmed in the present study. Nevertheless, the possible role of autoantibodies in individual cases cannot be ruled out, neither can the presence of other transitory autoimmune reactions after CHI. No conclusive evidence of sympathetic cochleolabyrinthitis was found.

• sensorineural hearing loss
• SNHL
• closed head injury
• CHI
• autoimmunity
• antibody
• HSP 70
• sympathetic cochleolabyrinthitis