Auditory brainstem responses (ABR), ipsilateral and contralateral acoustic reflexes and the masking level difference for speech (MLD) were studied in 29 patients with adrenomyeloneuropathy (AMN). Abnormalities were seen for all ABR components with Waves V and III affected to the greatest degree. For male patients with AMN, the I-III, III-V and I-V interpeak latency intervals were abnormal for a majority of patients. For female patients with AMN, the I-V and III-V interpeak latency intervals were abnormal for a majority of patients with the I-III interval less affected. Contralateral acoustic reflexes were elevated or absent for approximately 50% of ears. Ipsilateral acoustic reflexes were abnormal for 25% of ears. MLDs were significantly reduced in 72% of patients. When considered in terms of the earliest ABR wave abnormality, the earlier components of the ABR (i.e., Waves III and I) were the initial components impaired for the majority of ears. Word recognition in quiet was relatively unimpaired for all subjects. Despite the presence of marked ABR abnormalities, patients with AMN denied the presence of significant difficulty hearing.
Bibliographical noteFunding Information:
The study was supported by the Johns Hopkins University School of Medicine General Clinical Research Center (M01-RR00052) and the National Institutes of Health (R21 NS 045716, NINDS). We thank the patients and their families for their continued support for these studies. We acknowledge the contributions of K. Hollandsworth, W. Foreman, A. Snitcher, J. Pittman, and the entire ALD research team for providing excellent support.
- Acoustic reflex
- Adrenomyeloneuropathy (AMN)
- Auditory brainstem response (ABR)
- Masking level difference (MLD)
- Very long chain fatty acids (VLCFA)
- Word recognition