Obsessive-compulsive disorder after unilateral caudate nucleus bleeding.

Obsessive compulsive disorders (OCD) may be encountered after basal ganglia lesions of various aetiologies. These lesions are usually bilateral. We report here the case of a 24 years old man who developed a pure compulsive behavior after a unilateral left-sided caudate nucleus hemorrhage due to a cavernoma. The pathophysiology of this compulsive disorder probably reflects a frontal cortex deafferentation mechanism. Behavioral, psychological and medical (serotoninergic) treatments are usually proposed but the efficacy of such therapy remains to be investigated in secondary OCD.