The symptoms of Tourette syndrome vary greatly from one individual to another. The main feature of the condition is tics, both motor and auditory. These are almost always accompanied by psychiatric manifestations. Patients’ tics are uncontrollable and often occur intensely and repeatedly. Not all types of tics are present in a person at the same time; they may appear and then disappear, to be replaced by another type of tic.
Symptoms of Tourette syndrome improve or even disappear spontaneously in adulthood in 3/4 of patients, although it is not yet known why. Unfortunately, in 25% of cases, symptoms persist or worsen.
It is important to note that motor tics and auditory tics can be temporarily suppressed by an intense effort of will on the part of the patient, and may diminish during activities requiring intense concentration. Tics are also generally preceded by a premonitory sensation. These characteristics are important criteria in the diagnosis of Tourette’s syndrome.
Motor tics
Motor tics are sudden, involuntary and repeated muscle contractions and movements that are almost permanent. They primarily affect the upper body, the face in the form of grimaces, the head and shoulders/arms. Blinking, head shaking, arm or shoulder movements, each tic remains fairly localised. More complex movements may also represent tics such as hopping, looking back, touching or grabbing an object.
These tics can also be more complex, with a tendency to repeat movements observed in others, echopraxia, or a propensity to perform obscene gestures, copropraxia.
| In a study published in the journal Cortex, Cyril Atkinson-Clément and Yulia Worbe (Sorbonne University/APHP) in the “Mov’it: movement, investigations, therapeutics. Normal and abnormal movement: pathophysiology and experimental therapeutics” team at the Institut du Cerveau, show that, contrary to what we might think, control of motor impulsivity, a trait that characterises the ability to inhibit a movement or action that has already begun, is not correlated with tics in patients with Tourette syndrome. |
Auditory tics
Noise tics are the best known in the public mind, particularly coprolalia, the tendency to utter insults repeatedly and uncontrollably. Although this only affects a very small number of patients, it represents a social stigma that is very difficult for patients to live with. In the majority of cases, sound tics take the form of simple noises such as sniffing, throat clearing or coughing. More complex sounds, such as coprolalia, may also be present, but most often consist of the repetition of syllables or words, palilalia, without any connotation of coarse language, or the repetition of the words of others, echolalia.
Factors conducive to tics
A number of factors can influence the frequency and intensity of tics. Stress and fatigue tend to encourage them, while calm and concentration help to reduce them.
Associated psychiatric symptoms
Tourette syndrome is associated in the majority of cases with psychiatric and behavioural symptoms or pathologies, with attention deficit disorder (ADD), whether or not associated with hyperactivity, being present in a high proportion of patients. Obsessive-compulsive disorders (OCD) are also common, manifested by the presence of omnipresent obsessions. To relieve their anxiety, patients perform invasive rituals that have a considerable impact on their daily lives. Patients may also develop oppositional defiant disorder, anxiety, depression or autism spectrum disorder.
Eric Burgière’s team (CNRS) at the Institut du Cerveau is interested in the brain mechanisms underlying the generation of repetitive behaviours such as those present in obsessive-compulsive disorders and Tourette’s syndrome.