To the Editor.—In the recent article entitled "Auditory Function in Friedreich's Ataxia: Electrophysiologic Study of a Family" in the Archives (1981;107:254-256), Shanon and co-workers reported electrophysiologic abnormalities in a family suffering from Friedreich's ataxia. We were pleased that the abnormalities found by them were similar to those detected by us.1 The individual waves of brainstem auditory evoked potentials were either absent or unrecognizable in our cases, much like the diminished or absent auditory nerve N1, N2, and N3 responses noted in their study.
Shanon and co-workers invoke neuronal loss in cochlear nuclei and superior olivary complex to explain their findings and indicated the presence of a clinically inapparent neurologic deficit of the brainstem. We agree that a brainstem dysfunction exists in this group of patients. However, it is unclear if the brainstem disorder is primary or secondary to a more peripheral abnormality. A parallel situation