[Study on the prevalence of tic disorders in schoolchildren aged 7-16 years old in Wenzhou].

OBJECTIVE: To study the epidemiological features of tic disorders (TD) among schoolchildren in Wenzhou area. METHODS: Stratified cluster sampling was carried out to investigate TD in 9742 schoolchildren aged 7 to 16 years old in Wenzhou. RESULTS: The average prevalence rate of TD among school-age children was 104/10 000 (166/10 000 for males, 29/10 000 for females). There was a significantly higher prevalence rate for males than that for females (chi(2) = 43.96, P < 0.001, prevalence ratio = 5.7, prevalence ratio 95% CI: 3.20 - 10.30). The prevalence rates of clinical subtypes in males was significantly higher than that of females while pupils was significantly higher than that in high school students (chi(2) = 11.33, P < 0.01, prevalence ratio = 2.2, prevalence ratio 95% CI: 1.37 - 3.43). Prevalence rate of transient tic disorders (TTD), chronic motor vocal tic disorder (CMVTD), tourette syndrome (TS) were 34/10 000, 27/10 000 and 43/10 000 respectively with the highest among 9-10 years old group. The mean onset age of TD was 8.5 +/- 2.8 years. The peak of onset was among 6-10 year olds. The rate of delayed diagnosis of the disorders was 69.3% and the median in delayed diagnosis was 1.0 year. CONCLUSION: TD is a common disease with high rate of misdiagnoses among schoolchildren in Wenzhou area. Physicians and population should be trained to identify the syndromes and to practice correct diagnosis and effective treatment as early as possible.

[Study on the prevalence of Tourette syndrome in children and juveniles aged 7-16 years in Wenzhou area].

OBJECTIVE: To study the prevalence and distribution of Tourette syndrome (TS). METHODS: Nine thousand, seven hundred and forty-two children and juveniles aged 7 - 16 years in Wenzhou were studied, using cluster random sampling method. RESULTS: The prevalence of TS among school-age children was estimated to be 0.43% (0.74% for males and 0.07% for females). The prevalence of male children and juveniles was higher than that of female children and juveniles (chi(2) = 25.09, P < 0.001, prevalence ratio = 10.95, prevalence ratio 95% CI: 3.38 - 35.46). The highest prevalence of TS was between 9 - 10 years old. The mean age at onset of TS was 7.7 +/- 2.7 years, with 45.2% of them among 6 - 7 year olds. The rate of delayed diagnosis and rates of misdiagnosis and misclassification of the syndromes were 78.6%, 42.9% and 23.8%, respectively. CONCLUSION: Tourette syndrome had been a common disease of children and juveniles in Wenzhou area. The disease was correlated with age and sex, often misdiagnosed and misclassified. Physicians and as well as general publics should be trained to identify the cases.