RT Journal Article SR Electronic T1 Association of Group A Streptococcus Exposure and Exacerbations of Chronic Tic Disorders JF Neurology JO Neurology FD Lippincott Williams & Wilkins SP e1680 OP e1693 DO 10.1212/WNL.0000000000011610 VO 96 IS 12 A1 Martino, Davide A1 Schrag, Anette A1 Anastasiou, Zacharias A1 Apter, Alan A1 Benaroya-Milstein, Noa A1 Buttiglione, Maura A1 Cardona, Francesco A1 Creti, Roberta A1 Efstratiou, Androulla A1 Hedderly, Tammy A1 Heyman, Isobel A1 Huyser, Chaim A1 Madruga, Marcos A1 Mir, Pablo A1 Morer, Astrid A1 Mol Debes, Nanette A1 Moll, Natalie A1 Müller, Norbert A1 Müller-Vahl, Kirsten A1 Munchau, Alexander A1 Nagy, Peter A1 Plessen, Kerstin Jessica A1 Porcelli, Cesare A1 Rizzo, Renata A1 Roessner, Veit A1 Schnell, Jaana A1 Schwarz, Markus A1 Skov, Liselotte A1 Steinberg, Tamar A1 Tarnok, Zsanett A1 Walitza, Susanne A1 Dietrich, Andrea A1 Hoekstra, Pieter J. A1 , YR 2021 UL http://n.neurology.org/content/96/12/e1680.abstract AB Objective To examine prospectively the association between group A Streptococcus (GAS) pharyngeal exposures and exacerbations of tics in a large multicenter population of youth with chronic tic disorders (CTD) across Europe.Methods We followed up 715 children with CTD (age 10.7 ± 2.8 years, 76.8% boys), recruited by 16 specialist clinics from 9 countries, and followed up for 16 months on average. Tic, obsessive-compulsive symptom (OCS), and attention-deficit/hyperactivity disorder (ADHD) severity was assessed during 4-monthly study visits and telephone interviews. GAS exposures were analyzed using 4 possible combinations of measures based on pharyngeal swab and serologic testing. The associations between GAS exposures and tic exacerbations or changes of tic, OC, and ADHD symptom severity were measured, respectively, using multivariate logistic regression plus multiple failure time analyses and mixed effects linear regression.Results A total of 405 exacerbations occurred in 308 of 715 (43%) participants. The proportion of exacerbations temporally associated with GAS exposure ranged from 5.5% to 12.9%, depending on GAS exposure definition. We did not detect any significant association of any of the 4 GAS exposure definitions with tic exacerbations (odds ratios ranging between 1.006 and 1.235, all p values >0.3). GAS exposures were associated with longitudinal changes of hyperactivity–impulsivity symptom severity ranging from 17% to 21%, depending on GAS exposure definition.Conclusions This study does not support GAS exposures as contributing factors for tic exacerbations in children with CTD. Specific workup or active management of GAS infections is unlikely to help modify the course of tics in CTD and is therefore not recommended.ADB=anti-DNase B; ADHD=attention-deficit/hyperactivity disorder; ASOT=anti-streptolysin O; CTD=chronic tic disorders; CY-BOCS=Children's Yale-Brown Obsessive-Compulsive Scale; DSM-IV-TR=Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision; EMTICS=European Multicenter Tics in Children Study; GAS=group A Streptococcus; OCD=obsessive-compulsive disorder; OR=odds ratio; PANDAS=pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection; PANS=pediatric acute neuropsychiatric syndromes; SNAP-IV=Swanson, Nolan, and Pelham IV; TS=Tourette syndrome; YGTSS-TTS=Yale Global Tic Severity Scale–Total Tic Severity Score