Vitamin D levels in children and adolescents with chronic tic disorders: a multicentre study.

This study investigated whether vitamin D is associated with the presence or severity of chronic tic disorders and their psychiatric comorbidities. This cross-sectional study compared serum 25-hydroxyvitamin D [25(OH)D] (ng/ml) levels among three groups: children and adolescents (3-16 years) with CTD (n = 327); first-degree relatives (3-10 years) of individuals with CTD who were assessed for a period of up to 7 years for possible onset of tics and developed tics within this period (n = 31); and first-degree relatives who did not develop tics and were ≥ 10 years old at their last assessment (n = 93). The relationship between 25(OH)D and the presence and severity of tics, as well as comorbid obsessive-compulsive disorder (OCD) and attention-deficit/hyperactivity disorder (ADHD), were analysed controlling for age, sex, season, centre, latitude, family relatedness, and comorbidities. When comparing the CTD cohort to the unaffected cohort, the observed result was contrary to the one expected: a 10 ng/ml increase in 25(OH)D was associated with higher odds of having CTD (OR 2.08, 95% CI 1.27-3.42, p < 0.01). There was no association between 25(OH)D and tic severity. However, a 10 ng/ml increase in 25(OH)D was associated with lower odds of having comorbid ADHD within the CTD cohort (OR 0.55, 95% CI 0.36-0.84, p = 0.01) and was inversely associated with ADHD symptom severity (ß = - 2.52, 95% CI - 4.16-0.88, p < 0.01). In conclusion, lower vitamin D levels were not associated with a higher presence or severity of tics but were associated with the presence and severity of comorbid ADHD in children and adolescents with CTD.

Mycoplasma pneumoniae IgG positivity is associated with tic severity in chronic tic disorders.

Infectious pathogens may represent an environmental risk factor for chronic tic disorders (CTD). This cross-sectional study aimed to determine whether Mycoplasma pneumoniae (M. pneumoniae) IgG positivity is associated with the presence or severity of tics. We compared M. pneumoniae IgG positivity across three groups: children and adolescents (3-16 years) with CTD (CTD group; n = 302); siblings (3-10 years) of people with CTD who developed tics within a seven-year follow-up period (tic onset group; n = 51); siblings (4-10 years) who did not develop tics within the study period and were ≥10-years-old at their last assessment (unaffected group; n = 88). The relationship between M. pneumoniae IgG positivity and the presence and severity of tics was analysed using multilevel models controlling for site, family relatedness, sex, age, presence of comorbid obsessive-compulsive and/or attention-deficit/hyperactivity disorder and use of psychotropic medication. M. pneumoniae IgG positivity was not associated with the presence of CTD, or the first onset of tics as compared to siblings who remained unaffected. M. pneumoniae IgG positivity was associated with a higher tic severity score within the CTD group (ß = 2.64, s.e. = 1.15, p = 0.02). It is possible that M. pneumoniae infection influences tic severity in CTD or, that having more severe tics, increases the risk of infection. However, it is more likely that the association observed in this study reflects a propensity toward enhanced immune responses in people with CTD and that, rather than a causal relationship, infection and greater tic severity are indirectly linked via shared underlying immune mechanisms.

Association of Group A Streptococcus Exposure and Exacerbations of Chronic Tic Disorders: A Multinational Prospective Cohort Study.

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.

[Patients with tic disorders: widely known, yet underserved]. / Patienten mit Tic-Störungen: weit bekannt, doch unterversorgt.

Tic disorders typically start in early childhood and can be classified into provisional tic disorder (tics last <12 months) and chronic tic disorders (tics last > 12 months). The widely known chronic tic disorder Tourette's syndrome is featuring multiple motor and vocal tics. Tics are typically waxing and waning in frequency and intensity. Concentration and relaxation might decrease tics, whereas stress and excitement might increase tics. Psychiatric comorbidities, like obsessive-compulsive disorder, ADHD, depression and anxiety are common. The etiology is multifactorial with genetic and environmental interactions leading to a dysregulation of cortico-striato-pallido-thalamo-cortical networks.A correct diagnosis and psychoeducation are essential for patients as well as their relatives. Additional therapies are needed for patients with severe tics that cause physical impairment or great psychosocial stress. It is crucial to also treat psychiatric comorbidities. Psychotherapeutic interventions for tics include progressive muscle relaxation, habit reversal training, exposure and response prevention and comprehensive behavioral intervention for tics. First-line psychopharmacological treatment in Europe contains aripiprazole, tiapride and risperidone, which are all used off-label for tic disorders. Haloperidol remains the only approved medication for the pharmacotherapy of tics in Germany, but is rarely used due to its side effects. Cannabinoids gain interest as a new pharmacological option, but are mainly offered within the frame of studies.