Educationally significant hearing loss has been reported in 10% to 15% of children with congenital toxoplasmosis. As part of a pilot study to assess feasibility and safety of prolonged therapy for congenital toxoplasmosis, 30 congenitally infected infants and children were evaluated for auditory function. Serial testing, beginning within 2 months of birth, was performed. Availability of auditory brainstem response (ABR) testing made evaluation at an earlier age than previously possible. Six (20%) of the 30 infants had mild to moderate conductive type hearing loss associated with otitis media. No infant or child had sensorineural hearing loss. The better outcome we observed compared to previous reports of a 15% to 26% incidence of sensorineural hearing loss and 10% to 15% incidence of educationally significant, bilateral hearing impairment may be related to early initiation and/or prolonged institution of antimicrobial therapy. Continued followup to exclude progressive hearing impairment and study of larger numbers of children are needed to verify these preliminary findings.

To determine whether antibodies to supporting cells are associated with response to corticosteroids in patients with autoimmune sensorineural hearing loss. Design: Prospective analysis of antibody to inner-ear antigens. Setting: Collaborating otology practices in Pennsylvania, Michigan, and Indiana. Patients: Sixty-three patients with rapidly progressive unilateral or bilateral sensorineural hearing loss of unknown cause suggestive of autoimmune sensorineural hearing loss. Interventions: Pretreatment audiometry, serum analysis by Western blot (WB) and immunofluorescence (IF) tests, corticosteroid therapy, and follow-up audiometry. Main Outcome Measures: Antibody reactivity and audiogram changes were analyzed for association with response to treatment. Results: More than half of the patients (37/63) had antibodies to both a 68-to 72-kDa protein and to innerear supporting cells, 16 patients had positive results on one assay only, and 10 had negative results on both. Twenty-eight patients improved and 35 did not. The WB findings did not correlate with response. Of the WBpositive patients, 49% (21/43) improved, as did 35% (7/ 20) of the WB-negative patients (P=.30). In contrast, 53% (25/47) of IF-positive patients improved, compared with only 19% (3/16) in the IF-negative group (P = .02). Of those who improved, 89% (25/28) were IF positive. Conclusions: Antibody to an inner-ear supporting cell antigen was significantly associated with hearing improvement after corticosteroid therapy (relative rate, 2.8). Patients with IF-positive serum are nearly 3 times more likely to experience improved hearing with corticosteroid treatment than those who are IF negative. Antibodies to inner-ear supporting cell antigen may have value in diagnosis and treatment of patients with autoimmune sensorineural hearing loss.