Patients with Sydenham’s chorea (SC) seen at the Movement Disorders Clinic of the Federal University of Minas Gerais, Brazil, 1993-1998, were followed prospectively to determine the proportion with persistent symptoms more than 2 years (Group 2, N=16), and clinical features that might differentiate patients with duration less than 2 years (Group 1, N=16). No significant differences were found between Groups 1 and 2 in respect to M/F ratio (50/50 and 31/68, respectively, p=0.23); age at onset (10.9 and 9.3 years, p=0.23); % with arthritis (37 and 19, p=0.28); carditis % (31 and 50, p=0.28); hemichorea % (25 and 6, p=0.14); generalized chorea % (75 and 94, p=0.14); and severity of chorea (moderate to severe, p=0.59). All patients were taking penicillin to prevent recurrent streptococcal infection and RF. 
COMMENT. Sydenham’s chorea of moderate to severe degree may persist longer than 1 year in 50% of patients. Female gender and the presence of carditis may be risk factors for a longer duration of SC, although the data are not statistically significant.
These findings are at variance with the generally held belief that SC is self-limiting, usually lasting 2 to 6 months. However, other movement and behavioral disorders may occur as sequelae of SC, including tics, ADHD, and obsessive compulsive disorder. PANDAS, or pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection, are reviewed by Kurlan R , and Ped Neur Briefs July 1998;12;49-50.
Prednisone therapy and chorea duration. In a study of 600 cases of rheumatic fever seen between 1971 and 1999 and evaluated at the Primary Children’s Medical Center, Salt Lake City, UT, 142 (24%) had rheumatic chorea, and 69 (49%) received treatment, 57 with prednisone. Median time to 100% recovery was 2.75 weeks (range, 3-24 weeks) for prednisone-treated patients vs 10 weeks (range, 3-24 weeks) for untreated children (p<0.01). Hemichorea occurred in 39% of patients, a higher incidence than in the Brazil study.