Julie B. Leclerc

The puzzling question of inhibitory control in Tourette syndrome: A meta-analysis

HIGHLIGHTSImpulse control disorders are somewhat frequent in Tourette syndrome (TS) patients.Inhibitory control is impaired in TS patients, even when they do not have any comorbid disorder.Comorbid ADHD has a potentiating effect on the inhibitory deficits of TS patients.TS patients have impairments in verbal inhibition and Stroop interference, but show intact Go/No‐Go performance. ABSTRACT Tourette syndrome (TS) is a neuropsychiatric disorder involving motor and phonic tics. Inhibitory control is a key issue in TS, and many disruptive or impulsive behaviors might arise from inhibitory deficits. However, conflicting findings regarding TS patients’ inhibitory performance in neuropsychological tasks have been reported throughout the literature. Therefore, this meta‐analysis aimed to evaluate inhibitory control through neuropsychological tasks, and to analyze the factors modulating inhibitory deficits. To this end, a literature search was performed through MEDLINE and PsycINFO, to retrieve studies including neuropsychological tasks that assessed inhibitory control in TS patients. Of the 4020 studies identified, 61 were included in the meta‐analysis, for a total of 1717 TS patients. Our analyses revealed a small to medium effect in favor of inhibitory deficits in TS patients. This effect was larger in TS + ADHD patients, but pure TS patients also showed some inhibitory deficits. Therefore, deficits in inhibitory control seem to be an inherent component of TS, and are exacerbated when ADHD is concomitant.

The Effect of a New Therapy for Children with Tics Targeting Underlying Cognitive, Behavioral, and Physiological Processes

Tourette disorder (TD) is characterized by motor and vocal tics, and children with TD tend to present a lower quality of life than neurotypical children. This study applied a manualized treatment for childhood tics disorder, Facotik, to a consecutive case series of children aged 8–12 years. The Facotik therapy was adapted from the adult cognitive and psychophysiological program validated on a range of subtypes of tics. This approach aims to modify the cognitive–behavioral and physiological processes against which the tic occurs, rather than only addressing the tic behavior. The Facotik therapy lasted 12–14 weeks. Each week 90-min session contained 20 min of parental training. The therapy for children followed 10 stages including: awareness training; improving motor control; modifying style of planning; cognitive and behavioral restructuring; and relapse prevention. Thirteen children were recruited as consecutive referrals from the general population, and seven cases completed therapy and posttreatment measures. Overall results showed a significant decrease in symptom severity as measured by the YGTSS and the TSGS. However, there was a discrepancy between parent and child rating, with some children perceiving an increase in tics, possibly due to improvement of awareness along therapy. They were also individual changes on adaptive aspects of behavior as measured with the BASC-2, and there was variability among children. All children maintained or improved self-esteem posttreatment. The results confirm the conclusion of a previous pilot study, which contributed to the adaptation of the adult therapy. In summary, the Facotik therapy reduced tics in children. These results underline that addressing processes underlying tics may complement approaches that target tics specifically.

The Impact of a Cognitive–Behavioral Therapy on Event-Related Potentials in Patients with Tic Disorders or Body-Focused Repetitive Behaviors

Context Tic disorders (TD) are characterized by the presence of non-voluntary contractions of functionally related groups of skeletal muscles in one or multiple body parts. Patients with body-focused repetitive behaviors (BFRB) present frequent and repetitive behaviors, such as nail biting or hair pulling. TD and BFRB can be treated with a cognitive–behavioral therapy (CBT) that regulates the excessive amount of sensorimotor activation and muscular tension. Our CBT, which is called the cognitive–psychophysiological (CoPs) model, targets motor execution and inhibition, and it was reported to modify brain activity in TD. However, psychophysiological effects of therapy are still poorly understood in TD and BFRB patients. Our goals were to compare the event-related potentials (ERP) of TD and BFRB patients to control participants and to investigate the effects of the CoPs therapy on the P200, N200, and P300 components during a motor and a non-motor oddball task. Method Event-related potential components were compared in 26 TD patients, 27 BFRB patients, and 27 control participants. ERP were obtained from 63 EEG electrodes during two oddball tasks. In the non-motor task, participants had to count rare stimuli. In the motor task, participants had to respond with a left and right button press for rare and frequent stimuli, respectively. ERP measures were recorded before and after therapy in both patient groups. Results CoPs therapy improved symptoms similarly in both clinical groups. Before therapy, TD and BFRB patients had reduced P300 oddball effect during the non-motor task, in comparison with controls participants. An increase in the P300 oddball effect was observed posttherapy. This increase was distributed over the whole cortex in BFRB patients, but localized in the parietal area in TD patients. Discussion These results suggest a modification of neural processes following CoPs therapy in TD and BFRB patients. CoPs therapy seems to impact patients’ attentional processes and context updating capacities in working memory (i.e., P300 component). Our results are consistent with a possible role of the prefrontal cortex and corpus callosum in mediating interhemispheric interference in TD.

A Review of the Neuropsychological Dimensions of Tourette Syndrome

Neurocognitive functioning in Tourette syndrome (TS) has been the subject of intensive research in the past 30 years. A variety of impairments, presumably related to frontal and frontostriatal dysfunctions, have been observed. These impairments were found in various domains, such as attention, memory, executive functions, language, motor and visuomotor functions, among others. In line with contemporary research, other neurocognitive domains have recently been explored in TS, bringing evidence of altered social reasoning, for instance. Therefore, the aims of this review are to give an overview of the neuropsychological dimensions of TS, to report how neuropsychological functions evolve from childhood to adulthood, and to explain how various confounding factors can affect TS patients’ performance in neuropsychological tasks. Finally, an important contribution of this review is to show how recent research has confirmed or changed our beliefs about neuropsychological functioning in TS.

Tic Disorders and Tourette Syndrome

Publisher Summary “Tics are considered sudden, repetitive, recurrent, and nonrythmic unintentional motor movements or phonic productions that involve one or more muscle groups.” Tics can cause marked distress and significant impairment in social and occupational life because of their frequency and intensity. One particular source of psychological distress is the social embarrassment that arises from difficulty-controlling tic behavior in public. For this reason, secondary social anxiety, depression, and low self-esteem are commonly observed in sufferers. Tics have been described along two dimensions. One dimension pertains to the nature of activity reflected in the tic—that is, motor, phonic, sensory, or cognitive. The other pertains to the degree of muscle involvement. A number of areas within the field of Tourette Syndrome (TS) and tic disorders require future research. Further work needs to be done to clarify differences between impulsive and compulsive phenomena and to distinguish mental tics from voluntary thoughts, worries, and obsessional intrusions.