A 12-year-old boy with an acute exacerbation of obsessive-compulsive disorder (OCD) symptoms and tics following a Group A B-hemolytic streptococcal (GABHS) throat infection is reported from the National Institute of Mental Health, Bethesda, MD. Family history included Sydenham’s chorea in a maternal grandfather, OCD in the mother and paternal aunt, and Tourette’s syndrome in his 16-year-old brother. The boy had excessive throat-clearing, hyperactivity, and choreiform movements. Antistreptolysin O and DNAse B titers were elevated and a throat culture was positive for GABHS. Serial MRI scans performed to assess basal ganglia morphology in relation to symptom severity before and during plasmapheresis showed an initial caudate measure greater than two standard deviations above the mean for healthy boys. Within 1 day of the first plasmapheresis, the caudate volume decreased 24%, the putamen 12%, and the globus pallidus 28%. These fluctuations in the size of the basal ganglia correlated with the severity of symptoms of OCD which showed amelioration after plasmapheresis and a course of amoxicillin. The acute enlargement of the basal ganglia was most pronounced when the throat culture was positive for GAGHS. Less dramatic changes in size accompanied subsequent exacerbations of OCD, which occurred with negative throat cultures. 
COMMENT. A link between obsessive-compulsive disorder and basal ganglia dysfunction is supported by this case-study. The swelling of the basal ganglia was thought to represent an inflammatory reaction with edema secondary to a cross-reaction of antibodies against the invading bacteria.
An association between B-hemolytic streptococcal infection and Tourette’s syndrome in children with ADHD was previously correlated with serum antibodies against human caudate nucleus sections and elevated antistreptolysin titers in a study at Brown University, RI. (Kiessling LS et al. see Progress in Pediatric Neurology II, PNB Publ, 1994, pp236-7). Immunological treatments for autoimmune neuropsychiatric disorders associated with streptococcal infections, including ADHD and co-morbid symptoms, deserve further study.