MRI assessment of children with obsessive-compulsive disorder or tics associated with streptococcal infection

Objective: The authors assessed selective basal ganglia involvement in a su bgroup of children with obsessive-compulsive disorder (OCD) and/or ties bel ieved to be associated with streptococcal infection. Method: Using computer -assisted morphometric techniques, they analyzed the cerebral magnetic reso nance images of 34 children with presumed streptococcus-associated OCD and/ or ties and 82 healthy comparison children who were matched for age and sex . Results: The average sizes of the caudate, putamen, and globus pallidus, but not of the thalamus or total cerebrum, were significantly greater in th e group of children with streptococcus-associated OCD and/or ties than in t he healthy children. The differences were similar to those found previously for subjects with Sydenham's chorea compared with normal subjects. Conclus ions: These results support the hypothesis that there is a distinct subgrou p of subjects with OCD and/or ties who have enlarged basal ganglia, These f indings are consistent with the hypothesis of an autoimmune response to str eptococcal infection.