The sooner the better: clinical and neural correlates of impulsive choice in Tourette disorder

Reward sensitivity has been suggested as one of the central pathophysiological mechanisms in Tourette disorder. However, the subjective valuation of a reward by introduction of delay has received little attention in Tourette disorder, even though it has been suggested as a trans-diagnostic feature of numerous neuropsychiatric disorders. We aimed to assess delay discounting in Tourette disorder and to identify its brain functional correlates. We evaluated delayed discounting and its brain functional correlates in a large group of 54 Tourette disorder patients and 31 healthy controls using a data-driven approach. We identified a subgroup of 29 patients with steeper reward discounting, characterised by a higher burden of impulse-control disorders and a higher level of general impulsivity compared to patients with normal behavioural performance or to controls. Reward discounting was underpinned by resting-state activity of a network comprising the orbito-frontal, cingulate, pre-supplementary motor area, temporal and insular cortices, as well as ventral striatum and hippocampus. Within this network, (i) lower connectivity of pre-supplementary motor area with ventral striatum predicted a higher impulsivity and a steeper reward discounting and (ii) a greater connectivity of pre-supplementary motor area with anterior insular cortex predicted steeper reward discounting and more severe tics. Overall, our results highlight the heterogeneity of the delayed reward processing in Tourette disorder, with steeper reward discounting being a marker of burden in impulsivity and impulse control disorders, and the pre-supplementary motor area being a hub region for the delay discounting, impulsivity and tic severity.

Tourette and Trichotillomania

This chapter explores the treatment of trichotillomania (TTM; also referred to as hair pulling disorder) and Tourette disorder (TD). TTM and TD exist in separate diagnostic categories but exhibit functional similarities and respond to similar treatments. The chapter reviews the characteristics of each disorder. It then describes habit reversal training (HRT) and function-based interventions, which serve as core therapeutic elements in the treatment of both TTM and TD. The chapter also discusses additional treatment strategies that occur as part of standard protocols for both disorders, before looking at the treatment efficacy research. It considers the key features of the manual-based treatments (behavior therapy protocols), as well as ways these protocols can be flexibly implemented for those with TTM and TD. Finally, consistent with the call for “flexibility within fidelity,” the chapter provides an example of a flexible implementation of these treatments.

Action inhibition revisited: a new method identifies compromised reactive but intact proactive control in Tourette disorder

Tourette disorder (TD) is characterized by tics, which are sudden repetitive involuntary movements or vocalizations. Deficits in inhibitory control in TD patients remain inconclusive from the traditional method of estimating the ability to stop an impending action, which requires careful interpretation of a parameter derived from race model. One possible explanation for these inconsistencies is that race model's assumptions are often violated. Here, we used a pair of metrics derived from a recent alternative model to address why stopping performance in TD patients is unaffected by impairments in neural circuitry. These new metrics distinguish between proactive and reactive inhibitory control and estimate them separately. When these metrics were contrasted with healthy controls (HC), we identified robust deficits in reactive control in TD patients, but not in proactive control. The patient population exhibited difficulty in slowing down the speed of movement planning, which they compensated by their intact ability of procrastination.

Tourette and Learning Impairments

This chapter describes disorders of motor control, language, and learning. Tics are sudden, stereotyped, repetitive, unwanted movements, and a severe form is called Tourette disorder. Their strong association with obsessional disorders and attention deficit hyperactivity disorder (ADHD) is described. Developmental coordination disorder is a group of problems suggesting immaturity in control, both of fine adjustments and of large movements of the limbs. Impairments of language development include receptive, expressive, and pragmatic problems, and can extend to signed language. Problems in learning to read and write and acquire other skills needed for school learning are very frequent in the population. Neuropsychological formulations have been influential in guiding policy and practice in schools. Generalized learning difficulties are conceptualized as intellectual disability.