Evaluation of brainstem auditory evoked responses in patients with conversion disorders

Objective: The aim of this study was to detect any suboptimal brainstem lesions in patients with conversion disorder. Methods: This study included 37 patients (25 female, 12 male) with conversion disorder. Control's group included 30 healthy persons (22 female, 8 male). The diagnosis of conversion disorder was based on criteria of DSM IV. BAER was recorded at conventional and higher stimulus rate in these patients. The main BAER measurements analyzed were the I-III, III-V, and I-V interpeak intervals and the wave V amplitude. Results: There was significant difference for I-III (p<0,05), I-V (p<0,05) interpeak latencies between patient and controls groups at 10/s click rate. The only I-III interval differed significantly at 50/s click rate. Abnormal BAER result was seen in only one of 37 patients at the clicks of 10/s and 50/s, when the values exceeding 2.5 standard deviations above the means of the normal controls were considered abnormal. No significant correlation was found between diseased period and BAER latencies. Conclusion: The lower brainstem (cochlear nucleus, superior olivary complex and lateral lemniscus) has been affected in patients with conversion disorder.