Tourette disorder in North Dakota

Arithmetic performance in children with Tourette syndrome: relative contribution of cognitive and attentional factors

The study addressed the issue of arithmetic deficiencies in children with Tourette syndrome (TS) as well as explanations for such deficiencies. A total of 47 children with TS were assigned to three subgroups based on a composite attention score from the Test of Variables of Attention (TOVA). These children, along with 17 normal controls between 8 and 16 years of age, were tested on standardized measures of IQ, attention, visuospatial ability, and arithmetic achievement. The children also were administered an experimental calculation task with two levels of structure. Children with TS scored below controls on tests of IQ, attention, and arithmetic achievement but not visuospatial ability. The TS subgroup with the greatest impairment of attention accounted for most of the differences in arithmetic achievement. Regression analysis, based on the 47 children with TS, indicated that IQ and TOVA scores were the best predictors of arithmetic achievement. Likewise, the experimental calculation task indicated that the poor performance of some children with TS could be attributed to deficient attention. Irrespective of structure, children in the TS subgroup with the greatest attentional impairment made more attention (but not visuospatial) errors than did controls on the experimental task. Thus, on both the standardized and the experimental tasks, poor arithmetic skill was found only in children with TS who had significant attentional deficits.

Epidemiology of Tourette syndrome

The epidemiology of Tourette syndrome is difficult to characterize because there is no definitive diagnosis. Symptom intensity and frequency decrease with age and in social situations, and affected individuals are often unaware of their tics. This chapter reviews and summarizes current data on the prevalence, distribution, and risk factors for Tourette syndrome.

A Brazilian cohort of patients with Tourette's syndrome

The clinical features of 32 patients (24 males) with Tourette's syndrome in Brazil were studied. The mean age at onset was 7.1 years, tics being the first symptom in 71% and hyperactivity in 29%. Blinking, grimacing, and shoulder elevation were the most common motor tics and sniffing, throat clearing, and grunting noises, the most frequent vocal tics. Coprolalia was present in 28%, echolalia in 16%, palilalia in 9%, and copropraxia in 25% of patients. Attention deficit and hyperactivity disorder was diagnosed in 63%, and obsessive compulsive behaviour in 44% of patients. In 84% of patients there was a family history of tics whereas attention deficit and hyperactivity disorder and obsessive compulsive behaviour were respectively present in relatives of 19% and 53% of the patients studied. These data suggest that Tourette's syndrome in Brazil is not clinically different from other countries, supporting the notion that genetic factors play the most important part in its aetiology.