Inner Ear Disease

The hypothesis that a syndrome of sudden sensorineural hearing loss (SNHL) often accompanied by vestibular symptoms might be of autoimmune origin was firstly proposed by McCabe (1979) who based his findings on clinical features, presence of abnormal immunological tests and a positive response to immunosuppressive therapy. Since then, a number of syndromes characterized by SNHL with overlapping clinical features have been described and termed in different ways: autoimmune SNHL, immune-mediated inner ear disease (IMIED), idiopathic progressive bilateral SNHL, sudden SNHL, idiopathic SNHL, bilateral immune mediated Menière disease, autoimmune vestibulo-cochlear disorders (Rahman et al., 2001a), generating a great confusion in the identification of patients and in the evaluation of different studies. It is still debated whether we can define autoimmune all the cases of SNHL without any apparent cause. Although most of the Authors in the field refer to these cases with the term “Autoimmune Inner Ear Disease” or “Autoimmune Sensorineural Hearing Loss” (Solares et al., 2003; Mathews and Kumar, 2003), others (Stone and Francis, 2000; Garcia-Berrocal et al., 2003) still prefer the definition of IMIED, since not always an autoimmune process can be identified. Immune-mediated inner ear disease may be a process confined to the inner ear and antibodies against a vast array of different molecular weight inner ear antigens may be found in a percentage of these patients; in this case the process can be identified as an organ specific autoimmune disease. In other cases, IMIED is a feature of a systemic disorder such as primary vasculitides or of systemic autoimmune diseases. Indeed a systemic autoimmune disorder can be present in nearly one third of the patients with IMIED.