Tourette Syndrome and Chronic Tic Disorders: The Clinical Spectrum Beyond Tics

The clinical surveillance and active management of Tourette syndrome (TS) and other primary chronic tic disorders cannot be limited to tics, as these patients manifest a spectrum of sensory-, behavioral-, cognitive-, and sleep-related problems that have a major impact on their functioning and quality of life, influencing enormously clinical decision making on a routine basis. The sensory phenomena of primary tic disorders consist of premonitory urges and heightened sensitivity to external somatosensory and interoceptive stimuli. Recent evidence suggests that raised interoceptive awareness may be related to the classical premonitory urges associated with tics. The burden of behavioral comorbidities is very important in determining the degree of disability of patients with primary tic disorders. Only 10%-15% of these patients presents exclusively with a tic disorder. Obsessive-compulsive disorder (OCD) are common in TS, and the clinical distinction between compulsions and complex tics may be difficult in some cases. "Tic-related OCD" represents a phenomenologically characteristic subtype of OCD, also associated with "just right" phenomena. Probably the presence of comorbid attention deficit/hyperactivity disorder is the main determinant of cognitive dysfunction in TS patients and influences heavily also the risk of developing disruptive behaviors. Mood and anxiety disorders, impulse control disorders, rage attacks, "impulsive" tic-like behaviors (e.g., nonobscene socially inappropriate behaviors, and self-injurious behaviors), and autism spectrum disorders complete the wide psychopathological spectrum of primary chronic tic disorders. Moreover, specific sleep abnormalities have been reported in TS patients, although more research is needed on this specific clinical problem. As in other areas of clinical neuroscience, a comprehensive approach to both motor and nonmotor aspects of this group of disorders will help personalizing treatment interventions and, ultimately, improve quality of care.