[Deep brain stimulation, Parkinson's disease and neuropsychiatric complications]. / Stimulation cérébrale profonde, maladie de Parkinson et complications neuropsychiatriques.

Bilateral high-frequency stimulation of the subthalamic nuclei is now considered as the method of choice for the treatment of severe and advanced forms of Parkinson's disease. The technique improves patients' quality of life, disability, motor complications and allows the dose of dopaminergic treatment to be reduced. The dramatic motor benefits provided by the technique were firstly accompanied by a number of psychiatric complications--depression hypomania or mania, anxiety disorders or behavioural disorders--reflecting both the deleterious effect of modulation of the limbic circuit and the (inappropriate) selection of patients with past history of severe psychiatric disorders. Following a number of prospective studies, it is now considered that the rate of severe psychiatric side effects induced by deep brain stimulation is low, provided that the patients are well selected, the electrodes adequately placed and the postoperative follow-up appropriately performed. Interestingly, the favourable effects of the technique on both anxiety disorders (particularly obsessive compulsive disorders) and some behavioural disorders (mainly repetitive behaviour), strongly suggests that deep brain stimulation-associated modulation of associative and limbic circuits--through the basal ganglia--might be the method of choice for the future treatment of severe and medically refractory neuropsychiatric disorders such as Tourette's syndrome, obsessive compulsive disorders and addiction disorders.

[Tics and Tourette syndrome: diagnosis, course and treatment principles]. / Tics et syndrome de Gilles de la Tourette: diagnostic, évolution et principes de traitement.

The term "Tourette syndrome" designates the combination of tics with other symptoms. Gilles de la Tourette disease is one of its most frequent causes. It combines motor and vocal tics, with no identifiable cause, with self-mutilation and variable psychiatric comorbidity that may include obsessive-compulsive disorder (OCD) and other anxiety disorders, mood and personality disorders, and a syndrome of hyperactivity with attention disorders. The prevalence of Tourette syndrome is estimated at 0.1-1% of the general population. The condition begins during childhood and develops in a succession of periods of relative aggravation and remission of the tics. Most patients show improvement at the end of adolescence, but symptoms can persist into adulthood in approximately one third of patients. The cause of Gilles de la Tourette disease is unknown, but the role of genetic susceptibility has been suggested together with dysfunctions of the dopaminergic system and of neuron networks in associative and limbic areas of the basal ganglia and the prefrontal cortex. Treatment of Tourette syndrome and severe tics is often difficult and requires a multidisciplinary approach (neurologist, psychiatrist, psychologist and social workers). In mild forms, information and psychological management are usually recommended. Drug treatments--including neuroleptics--are essential in the moderate to severe forms of the disease. Psychiatric comorbidities, when present, often justify specific treatment. For the most severe forms of Gilles de la Tourette disease, preliminary results of treatment by deep brain stimulation of the associative and limb areas of the thalamus or pallidum have produced real hope of treatment, but nonetheless require confirmation.