Lack of Effect of Intravenous Immunoglobulins on Tics: A Double-Blind Placebo-Controlled Study

Background: Case studies and a placebo-controlled study previously suggested the effectiveness of immunomodulatory therapy in patients with tic or related disorders whose symptoms show a relationship with streptococcal infections. No data are available on the effectiveness of intravenous immunoglobulins (IVIG) on tic severity in unselected tic disorder patients.

Method: Thirty patients with a DSM-IV tic disorder were randomly assigned to IVIG (1 g/kg on 2 consecutive days; mean age = 28.71 years; range, 14-53 years) or placebo (mean age = 30.73 years; range, 14-63 years). Symptoms were rated with the Yale Global Tic Severity Scale, the Yale-Brown Obsessive Compulsive Scale, and the Clinical Global Impressions scale of symptom change with regard to tic severity. These were used at baseline and on weeks 2, 4, 6, 10, and 14 posttreatment, after which blinding was broken. The study was conducted from March through August 2002.

Results: We observed no significant differences between both treatment groups regarding posttreatment changes in tic severity. Severity of obsessions and compulsions, which was in the subclinical range, decreased significantly in the IVIG group compared with the placebo group at week 6 (p = .02). Then, there was a 32.3% improvement in the IVIG group compared with baseline. Though this improvement was maintained over the following 8 weeks, no statistically significant differences between the IVIG and the placebo group with regard to improvements in obsessions and compulsions were detected at subsequent assessments. IVIG treatment was associated with significantly more side effects than placebo, most notably headache.

Conclusion: Based on the present results, IVIG cannot be recommended in tic disorders.