P72 – 2355: Auditory function in patients with childhood adrenoleukodystrophy

Objective The objective of our study is to investigate auditory function in patients with childhood adrenoleukodystrophy (ALD). Methods Subjects were forty-five patients with ALD aged 2 and 11/12 years to19 yearrs. Twelve patients were asymptomatic. Tests for subjective auditory function were pure tone audiometry, verbal sound discrimination test, environmental sound discrimination test, and token test. Objective test was auditory brainstem response (ABR). Verbal auditory agnosia was defined as decreased scores of verbal sound discrimination and/or token test among patients who could respond tasks. Nonverbal agnosia was also defined as high error rate of environmental sound discrimination. Results Thirty seven patients showed normal hearing threshold and 8 patients showed elevated hearing threshold. ABR only could be performed in the youngest patient who could not perform our scheduled subjective tests. Auditory verbal agnosia was diagnosed in 10 patients. Auditory verbal and nonverbal agnosia was diagnosed in 12 patients. No patient was diagnosed as pure nonverbal agnosia. Thus 22 among 44 children showed abnormal results of subjective audiometry. Abnormal prolongation of central conduction time of brainstem was present in 15 among 45 patients. Patients who showed abnormal results in any kinds of auditory function tests were 29 among 44 patients. Conclusion Rate of abnormal auditory function in any kinds was very high (66%) compared with the previous reports. Patients with auditory agnosia have difficulty in daily living but are often misdiagnosed. Thus, to evaluate precise auditory function in patients with ALD is important. Subjective tests, especially word discrimination test is essential other than ABR and/or pure tone audiometry.