Preliminary findings of antistreptococcal antibody titers and basal ganglia volumes in tic, obsessive-compulsive, and attention-deficit/hyperactivitydisorders

Background: Previous studies have provided preliminary serological evidence supporting the theory that symptoms of tic disorders or obsessive-compulsi ve disorder (OCD) may be sequelae of prior streptococcal infection. It is u nclear, however, whether previously reported associations with streptococca l infection were obscured by the presence of diagnostic comorbidities. It i s also unknown whether streptococcal infection is associated in vivo with a natomical alterations of the brain structures that have been implicated in the pathophysiology of these disorders. Methods: Antistreptococcal antibody titers were measured in 105 people diag nosed as having CTD, OCD, or attention-deficit/hyperactivity disorder (ADHD ) and in 37 community controls without a disorder. Subjects were unselected with regard to their history of streptococcal exposure. Basal ganglia volu mes were measured in 113 of these subjects (79 patients and 34 controls). Results: A DSM-IV diagnosis of ADI-ID was associated significantly with tit ers of 2 distinct antistreptococcal antibodies, antistreptolysin O and anti -deoxyribonuclease B. These associations remained significant after control ling for the effects of CTD and OCD comorbidity. No significant association was seen between antibody titers and a diagnosis of either CTD or OCD. Whe n basal ganglia volumes were included ill these analyses, the relationships between antibody titers and basal ganglia volumes were significantly diffe rent in OCD and ADI-ID subjects compared with other diagnostic groups, High er antibody titers in these subjects were associated with larger volumes of the putamen and globus pallidus nuclei. Conclusions: These findings suggest that the prior reports of an associatio n between antistreptococcal antibodies and either CTD or OCD may have been confounded by the presence of ADHD. They also support the hypothesis that i n susceptible persons who have ADHD or OCD, chronic or recurrent streptococ cal infections are associated with structural alterations in basal ganglia nuclei.