ABSTRACT
INTRODUCTIONFirst described by the French physician, Georges Gilles de la Tourette, who published his findings on nine patients in 1885 [2], Tourette’s syndrome (TS) has been studied for over a century. Today, it is considered a neurodevelopmental disorder characterized by the presence of multiple, chronic motor tics and one or more vocal/phonic tics, often associated with behavioral comorbidities [3]. Although the symptoms commonly abate before age 18, a subset of patients remains symptomatic into adulthood. While once considered rare, recent community epidemiologic studies involving direct examination of subjects indicate that 1-3% of school children have TS [5, 6]. Non-invasive therapeutic approaches include psychotherapy and pharmacotherapy. In 1999, deep brain stimulation (DBS) emerged as a new therapeutic option for patients with severe TS refractory
to traditional therapies; since then, over 100 patients have been treated with DBS (for a detailed review see Schrock et al., 2015 [1]). Symptom Characteristics
Tics associated with TS take several forms. Motor tics are abrupt, involuntary, repetitive movements. They are categorized as “simple” when they involve a single movement, such as head jerking or eye blinking, or as “complex,” when they involve combinations of movements that simulate purposeful actions, such as neck twisting plus facial grimacing. Phonic tics are simple, involuntary sounds such as grunting, snorting, or barking. Verbal tics consist of single words or word phrases which can take the form of coprolalia (vocalization of socially inappropriate words), echolalia (repetition of the words or phrases of others), and palilalia (repetition of one’s own words or phrases). Although tics are the defining symptom, up to 90% of patients with TS are also affected by comorbid psychopathologies, including obsessivecompulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD) [4].
