Brainstem Evoked Potential Indices of Subcortical Auditory Processing After Mild Traumatic Brain Injury.

The study included 32 people with mild traumatic brain injury and 32 controls, and the subgroup with abnormal auditory behavioral results was only 9 people after excluding 4 for unreliable effort. Many comparisons were not corrected for multiple testing, so some significant results could have occurred by chance. The abnormal-performance subgroup was older than the other mild traumatic brain injury subgroup and controls, and it also had a higher right-ear pure-tone average than controls, so age and mild hearing differences may have contributed to the brainstem response differences. The auditory test battery did not include all tests recommended for diagnosing central auditory processing disorder, so the behavioral classification may not capture every auditory processing problem. Some brainstem recordings were excluded because of artifact, and no formal assessment was made of whether participants were asleep or relaxed during testing.

Do not conclude that mild traumatic brain injury causes a reliable brainstem auditory processing abnormality. At the whole-group level, click and speech brainstem responses did not differ significantly between the mild traumatic brain injury group and controls. The significant differences appeared only in a small subgroup with abnormal auditory behavioral tests, and that subgroup was older and had slightly worse right-ear hearing thresholds than controls.