Case series: increased vulnerability to obsessive-compulsive symptoms with repeated episodes of Sydenham chorea.

The association between obsessive-compulsive symptoms (OCS) and Sydenham chorea (SC) supports the hypothesis of a common neuroimmunological dysfunction in basal ganglia associated with group A beta-hemolytic streptococcal infection underlying both conditions. Four children with 2 distinct SC episodes were evaluated to assess the course of OCS. All patients developed OCS during their second episodes (3 met criteria for obsessive-compulsive disorder [OCD]), but not in their first episodes (2 developed OCS and met criteria for OCD). These data suggest that the recurrence of SC episodes may result in a cumulative effect, thus increasing the risk of appearance and intensification of OCS.