Obsessive-compulsive disorder after traumatic injury to the right frontal and left temporal lobes: A case report.

Background: Obsessive-compulsive disorder (OCD) is a common neuropsychiatric disorder affecting many behaviors in daily life. Hyperactivity of the fronto-striato-thalamic circuit via the orbitofrontal cortex (OFC) is assumed to play a major role in the pathophysiology of OCD; however, its pathogenesis is not fully understood. Several reports have described the development of OCD after traumatic brain injury (TBI); however, the pathogenesis of post-TBI OCD remains unknown. Moreover, patients with TBI often have a variety of sequelae, including cognitive dysfunction and mood disorders, which make the diagnosis and treatment of OCD more complex. Case presentation: We report the case of a 17-year-old Japanese male who developed OCD after traffic trauma. The patient developed a fear of contamination and checking compulsion after injuring his right OFC and left temporal lobe when he ran into a running truck during a suicide attempt. We believe that the patient's fear of contamination can be diagnosed as true post-TBI OCD. However, his memory impairment was significant, and we considered his checking compulsion to be strongly influenced by cognitive dysfunction due to TBI. We attempted behavioral therapy for OCD; however, sufficient results were not achieved because of the interference from the sequelae of TBI. Conclusion: It is not rare for OCD symptoms to appear after TBI. Differentiating the OCD symptoms induced by brain injury or cognitive dysfunction associated with TBI is important to determine a treatment strategy.