Behavioral Therapy for Tourette Syndrome and Chronic Tic Disorders

Purpose of review: To summarize behavioral interventions for the treatment of primary tic disorders. Recent findings: Although tics were attributed to a disordered weak volition, the shift towards neurobiological models of tic disorders also transformed nonpharmacologic treatment practices. Current international guidelines recommend habit reversal training, comprehensive behavioral intervention, and exposure and response prevention as first-line therapies for tics. Appropriate patient selection, including age and presence of comorbidities, are salient clinical features that merit consideration. Evidence for further behavioral interventions is also presented. Summary: Currently recommended behavioral interventions view tics as habitual responses that may be further strengthened through negative reinforcement. Although availability and costs related to these interventions may limit their effect, Internet-based and telehealth approaches may facilitate wide accessibility. Novel nonpharmacologic treatments that take different approaches, such as autonomic modulation or attention-based interventions, may also hold therapeutic promise

Volitional inhibition of tics in Tourette syndrome

Tics are a hyperkinetic movement disorder. They are defined as movements or sounds that typically resemble voluntary actions, but appear repetitive, often exaggerated in intensity and are not bound to a certain social context. Tics are typically preceded by a phenomenally strong sensory experience known as the premonitory urge. Crucially, and different from most other hypekinesias, tics can be voluntarily inhibited on demand. Tics are prevalent in many disorders, including neurodevelopmental syndromes and neurometabolic or neurodegenerative conditions, but are most commonly documented in primary tic disorders. Tourette syndrome (TS) is the prototypical primary tic disorder encountered in clinics and affects up to 1% of school-age children. The predominant pathophysiological models of tic disorders view the abnormal motor behaviours as the result of pathological gain increase of neuromotor signals within the circuitry that also generates voluntary actions. Crucially, they introduce a concept of voluntary tic inhibition, as the capacity to exert top-down inhibitory control to temporarily suppress the pathologically increased neuromotor activity. In-depth understanding of voluntary tic inhibition may, thereby, have important implications for the regulatory control of tics, including the development and implementation of more efficient treatment interventions. In the medical literature, the term of voluntary tic inhibition has also been synonymously used with tic control. However, the latter term has also been used to describe a range of different processes related to tic reduction not relevant to the specific designation that is suggested here. Voluntary tic inhibition (or voluntary tic control) denotes a specific cognitive effortful process of tic suppression. The inhibitory process is an intentional and goal-directed activity, which is specifically decided and initiated by the patients themselves, and, thereby, is also amenable to reinforcement. In a progression of five consecutive studies, we here explore the behavioural associations and neural correlates of voluntary tic inhibition in adolescents and adults with tic disorders and TS. First, we explore the putative association between premonitory urges and voluntary tic inhibition. Importantly, we provide experimental evidence to support the view that the two processes are not directly related. We then examine the characteristic capacity of voluntary tic inhibition to specifically suppress tic movements without affecting motor performance for voluntary actions. We assess the relation between the voluntary motor system and voluntary tic inhibitory control and introduce the concept of neuromotor noise in the pathophysiology of tic disorders to explain our findings. We also discuss the spatial characteristics of voluntary tic inhibition and provide a model of somatotopic-specificity of voluntary inhibitory tic control. Finally, we review the pathophysiological concept of deficient action control underlying the manifestation of tics and provide experimental evidence against it. We also examine the neural correlates of inhibitory control both over voluntary actions and involuntary tic behaviours. Current limitations in the research of voluntary tic inhibition are discussed and future directions of the scientific study of voluntary tic inhibitory control are suggested

Clinical Features That Evoke the Concept of Disinhibition in Tourette Syndrome

The capacity to efficiently control motor output, by either refraining from prepotent actions or disengaging from ongoing motor behaviors, is necessary for our ability to thrive in a stimulus-rich and socially complex environment. Failure to engage in successful inhibitory motor control could lead to aberrant behaviors typified by an excess of motor performance. In tic disorders and Tourette syndrome (TS) - the most common tic disorder encountered in clinics - surplus motor output is rarely the only relevant clinical sign. A range of abnormal behaviors is often encountered which are historically viewed as "disinhibition phenomena". Here, we present the different clinical features of TS from distinct categorical domains (motor, sensory, complex behavioral) that evoke the concept of disinhibition and discuss their associations. We also present evidence for their consideration as phenomena of inhibitory dysfunction and provide an overview of studies on TS pathophysiology which support this view. We then critically dissect the concept of disinhibition in TS and illuminate other salient aspects, which should be considered in a unitary pathophysiological approach. We briefly touch upon the dangers of oversimplification and emphasize the necessity of conceptual diversity in the scientific exploration of TS, from disinhibition and beyond

"I swear it is Tourette's!": On functional coprolalia and other tic-like vocalizations.

Coprolalia in neuropsychiatry is typically associated with tic disorders, in particular Gilles de la Tourette syndrome. To date, there has been no report of functional coprolalia. Here, we provide the clinical characteristics of 13 adolescent and adult patients with coprolalic and other functional tic-like complex vocalizations who, on the basis of these symptoms, were misdiagnosed with a primary tic disorder, most commonly Gilles de la Tourette syndrome. We describe similarities and highlight the differences from primary tic disorders in order to provide a pragmatic list of clinical clues that will facilitate correct diagnostic labeling and thereby treatment. Finally, we emphasize that the distinction between a primary and a functional tic disorder should rely on a combination of neuropsychiatric symptoms and signs and not on the presence of single, however striking, abnormal behaviors, such as coprolalia

Volitional action as perceptual detection: Predictors of conscious intention in adolescents with tic disorders

AbstractVoluntary actions are accompanied by a distinctive subjective experience, so that they feel quite different from physically similar involuntary movements. However, the nature and origin of this experience of volition remain unclear. Voluntary actions emerge during early childhood, in parallel with reduction of involuntary movements. However, the available markers of the experience of volition, notably Libet's mental chronometry of intention, cannot readily be used in young children. In Gilles de la Tourette syndrome (GTS), however, involuntary tic movements may coexist with voluntary control into adulthood. Therefore, adolescents with GTS could potentially confuse the two classes of movement. We have measured the temporal experience of voluntary action in a well-characterised group of adolescents with GTS, and age-matched controls. We replicated previous reports of a conscious intention occurring a few hundred milliseconds prior to voluntary keypress actions. Multiple regression across 25 patients' results showed that age and trait tic severity did not influence the experience of conscious intention. However, patients with stronger premonitory urges prior to tics showed significantly later conscious intentions, suggesting that the anticipatory experience of one's own volition involves a perceptual discrimination between potentially competing pre-movement signals. Patients who were more able to voluntarily suppress their tics showed significantly earlier conscious intention, suggesting that the perceptual discrimination between different action classes may also contribute to voluntary control of tics. We suggest that the brain learns voluntary control by perceptually discriminating a special class of internal ‘intentional’ signals, allowing them to emerge from motor noise

Premonitory urges are associated with decreased grey matter thickness within the insula and sensorimotor cortex in young people with Tourette syndrome

Tourette syndrome (TS) is a neurological disorder characterized by vocal and motor tics and is associated with cortical–striatal–thalamic–cortical circuit (CSTC) dysfunction and hyperexcitability of cortical limbic and motor regions, which are thought to lead to the occurrence of tics. Importantly, individuals with TS often report that their tics are preceded by ‘premonitory sensory phenomena’ (PSP) that are described as uncomfortable cognitive or bodily sensations that precede the execution of a tic, and are experienced as a strong urge for motor discharge. While the precise role played by PSP in the occurrence of tics is controversial, PSP are nonetheless of considerable theoretical and clinical importance in TS, not least because they form the core component in many of the behavioural therapies that are currently used in the treatment of tic disorders. In this study, we investigated the brain structure correlates of PSP. Specifically, we conducted a whole-brain analysis of cortical (grey matter) thickness in 29 children and young adults with TS and investigated the association between grey matter thickness and PSP. We demonstrate for the first time that PSP are inversely associated with grey matter thickness measurements within the insula and sensori-motor cortex. We also demonstrate that grey matter thickness is significantly reduced in these areas in individuals with TS relative to a closely age- and gender-matched group of typically developing individuals and that PSP ratings are significantly correlated with tic severity

Aggression Toward Others Misdiagnosed as Primary Tics

Background: Tics describe a wide range of sudden and repetitive behaviors. Their multifaceted clinical features may resemble other explosive behaviors, including repetitive episodes of aggression toward others (allo-aggression) reported by subjects without tics. Here, we document 3 exemplary cases that help disentangle allo-aggressive behaviors from tics. Cases: We report 3 cases who presented with an array of complex repetitive behaviors, most notably allo-aggression (eg, sudden kicking, hitting, slapping and biting others, or pushing someone off a bike), which were misdiagnosed as primary tics. In all cases, additional symptoms, such as blackouts, feeling of being controlled by different personalities, or being empowered by repetitive behaviors, and examination pointed toward different neuropsychiatric diagnoses. Conclusions: Repetitive allo-aggressive behaviors are not part of the range of motor manifestations of tics. This observation not only has important medico-legal implications but is also relevant for the overall perception of Tourette syndrome and other primary tic disorders