Colour Doppler echocardiography in children with group A streptococcal infection related tic disorders.

BACKGROUND & OBJECTIVES: A possible relationship has been suggested between tic disorders and streptococcal infections. To understand the complex relationship between streptococcal infections and neuropsychiatric disorders in children the present study was done on colour Doppler echocardiography of patients with possible post-streptococcal tic disorders. METHODS: The patients were 23 children (22 males, 1 female) affected by tic disorders, who at the time of the observation presented (or had presented in the past) signs of streptococcal infections temporally related to the onset or recrudescence of tic disorders. Echocardiographic examination and laboratory tests were performed on these children. RESULTS: In 4 cases a mild mitral insufficiency and in 8 cases a minimal mitral insufficiency was seen, all haemodynamically not significant. Follow up studies (up to 1 yr) showed the consistency and persistence of these findings. Of the 12 patients with echocardiographic abnormalities, 10 displayed very high anti streptolysin O (ASO) titres, 5 showed positive cultures for GAS and 9 had abnormal ESR, even if no significant differences were found in respect to patients with tics and normal echocardiography. INTERPRETATION & CONCLUSION: With the caution due to the design of study and to low number of patients, our data seem to indicate that the pathophysiology of GAS-infection related tic disorders is similar to that SC, at least in some cases.

Characterisation of group A streptococcal (GAS) isolates from children with tic disorders.

BACKGROUND & OBJECTIVES: An association between the onset or recrudescence of some neuropsychiatric disorders in children such as tic disorders and group A streptococcal (GAS) infections has been suggested. No information is available on the characterization of GAS strains associated with such disorders. The present study was undertaken to characterize the GAS strains isolated from children with tic disorders and to determine and correlate the antistreptolysin O (ASO) titre with the presence of GAS. METHODS: During 1996-2001, 368 children with tic disorders were investigated for possible exposition to streptococcal antigens. All children, at the time of the first visit and during the follow up visits were apparently healthy and showed no clinical evidence of streptococcal infections or post streptococcal sequelae. Blood and throat swab samples were collected and serological and bacteriological tests done. The isolates obtained were investigated for T pattern, M protein and emm type, as well as for the production of protease. RESULTS: Of the 800 throat swabs studied 100, corresponding to 67 patients, were positive for GAS; 49 children were found positive for GAS only once during the study, 18 had more than one sample positive for different serotypes, 8 were positive twice or more for the same type. ASO titres of these children were, in general, elevated. Five types, namely type M12, 3, 13, 11, 1, accounted for 39 per cent of the isolates, M12 being the most common, but a large number of different types were also found. A large number of isolates (62%) showed an elevated prodution of protease in the casein plate assay. INTERPRETATION & CONCLUSION: Despite the high level of ASO titres found, the results were not in favour of a particular virulence or invasivity of the isolates. Only a few colonies per sample were found indicating that factors different from the microbial virulence play a role in this type of disease.