Brain Stem Responses and Cochlear Action Potential in Cases of Post-Traumatic Disorders of Head and Neck Accompanied by Auditory Disturbances with Special References to Topographic Recording of Brain Stem Responses over the Scalp

The relationship between the threshold of AP or BSR and the threshold for air conduction of pure tone was examined in 72 patients with post-traumatic disorders of the head and neck accompanied by hearing disorders. In most patients, the threshold of AP and BSR clearly corresponded to the threshold for air conduction of pure tone in the frequency of stimulated sound. Topographic recording of BSR waves was attempted, despite the absence or scarcity of difference in threshold for air conduction of pure tone between right and left ears. The BSR waves were low on the operated side over the scalp, in 4 of 7 who had undergone surgery.
In such cases the I-V BSR waves differed in from the left. The topographic recording of BSR of cases of post-traumatic disorders of the head and neck were accompanied by central nervous system disorders, and showed responses different from those with normal hearing.
Thus, recording and examination of induced auditory responses, such as BSR and AP provide informations for objective determinations of auditory disturbances, central nervous system disorders, and psychological or psychic disturbances.