Brainstem involvement in obsessive-compulsive disorder

We investigated the possible involvement of the brainstem in the pathology of obsessive-compulsive disorder. Brainstem auditory evoked potentials (BAEPs) were collected from a population of neurotics (100 patients), including a group of 50 subjects suffering from obsessive-compulsive disorder (OCD) and the rest having generalized anxiety disorder. Twenty-five, age- and sex-matched, healthy volunteers served as controls. BAEPs were recorded by standard techniques as recommended by the AEEGS Clinical Evoked Potentials Guidelines. A one-way analysis of variance and the Fisher least-significant difference test were used for statistical analysis of the data. After stimulation of the right ear, a significant increase of wave I-V interpeak latency was found in the two groups of patients as compared with that of controls. Moreover OCD patients had a significantly reduced amplitude of wave III when compared to that of the control group. Our electrophysiological data suggest a possible involvement of brainstem in OCD pathogenesis. We discuss our findings in relation to biochemical, anatomical and physiological alterations described in the literature for serotonin-dependent systems.