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Movement disorders such as Parkinson's disease (PD), essential tremor (ET) and dystonia can benefit from deep brain stimulation (DBS). DBS is considered when symptoms are disabling despite optimal medical therapy. Contraindications include dementia, uncontrolled psychiatric disease and/or comorbid conditions with potential for evolution. Targets are the subthalamic nucleus for PD, the ventral intermediate nucleus for ET and the globus pallidus internus for dystonia. The beneficial effet of DBS has been well documented for symptom control. Optimal target localization of the electrodes reduces the occurrence of side-effects. Stimulation-induced adverse effects can usually be abolished by turning the stimulation off, changing the active contact or other stimulation parameters.

Introduction: Studies of dystonia are heterogeneous and there are no studies on this disease in Tunisia. The aim of our study was to determine the frequency of dystonia in the hospital population, to identify different forms of dystonia according to age of onset, distribution, to determine etiologies and to describe treatment., Methods: We conducted a prospective study over a 5-year period (from January 2005 to November 2009) including all patients diagnosed with dystonia and followed at the Child and Adolescent Neurology Department and "Movement Disorders and Botulinum Toxin" consultation of the National Institute of Neurology of Tunis., Results: Two hundred patients were included (2.2% of our patients). Mean age was 26.4±21.4 years and sex ratio H:F 1.3. Consanguinity rate was 29%. Main features of dystonia were action dystonia (78.5%), generalized forms (47%) and secondary forms (58%). A pyramidal syndrome and other movement disorders were the most common signs associated with dystonia (36.5% and 33.5% respectively). In the group of secondary dystonia, mains etiologies were dystonia due to exogenic agent (56%), neuro-metabolic diseases (26%), hereditary degenerative disease (13%) and psychogenic dystonia (5%). Dystonia was primary in 44% (84 patients). Different treatments were used and a dramatic improvement in some patients was noted with levodopa and botulinum toxin injections. A multidisciplinary approach associated with medical treatment led to recovery or improved prognosis., Discussion and Conclusion: Very few studies have been devoted to reporting a large series of dystonic patients. Our study is the first to describe both primary and secondary dystonia in 200 Tunisian patients. The presence of familial dystonia in our country suggests a genetic origin. Further work including genetic analysis with a screening of known mutations responsible for dystonia and the informative families with unknown mutations would be useful. Specific studies designed to identify new genes causal in dystonia are needed., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

Psychogenic Movement Disorders (PMDs) are a subtype of conversion disorder, classified under somatoform disorders in the DSM. Diagnosis and treatment of PMDs are challenging for both neurologists and psychiatrists. Typical clinical characteristics of these disorders are acute onset, fast progression, movement patterns incongruent with organic movement disorders, distractibility, variability and simultaneous occurrence of various abnormal movements and dysfunctions. The diagnosis of PMDs should not be regarded as a diagnosis of exclusion and electrophysiology is not always helpful. The cause of PMDs is unknown and the underlying brain mechanisms remain uncertain. However, recent functional magnetic resonance imaging studies have demonstrated altered blood flow in conversion disorders that may reflect changes in synaptic activity. Involvement of allied health professionals and psychotherapy continue to be the mainstay of treatment., (Copyright © 2012. Published by Elsevier Masson SAS.)

Introduction: Over the last few years, deep brain stimulation techniques, with targets such as the subthalamic nucleus or the pallidum, have bee found to be beneficial in the treatment of Parkinson's disease and dystonia. Conversely, therapeutic strategies of cortical stimulation have not yet been validated in these diseases, although they are known to be associated with various cortical dysfunctions. Transcranial magnetic stimulation (TMS) is a valuable tool for non-invasive study of the role played by the motor cortex in the pathophysiology of movement disorders, in particular by assessing various cortical excitability determinants using single or paired pulse paradigms. In addition, repetitive TMS (rTMS) trains can be used to study the effects of transient activity changes of a targeted cortical area., Background: Studies with TMS revealed significant motor cortex excitability changes, particularly regarding intracortical inhibitory pathways, both in Parkinson's disease and in dystonia, and these changes can be distinguished owing to the resting state or to the phases of movement preparation or execution. However, more specific correlation between electrophysiological features and clinical symptoms remains to be established. In addition, the stimulation of various cortical targets by rTMS protocols applied at low or high frequencies have induced some clear clinical effects., Perspectives: The TMS effects are and will remain applied in movement disorders to better understand the role played by the motor cortex, to assess various types of treatment and appraise the therapeutic potential of cortical stimulation., Conclusion: TMS provides evidence for motor cortex dysfunction in Parkinson's disease or dystonia. Moreover, rTMS results have opened new perspectives for therapeutic strategies of implanted cortical stimulation. By these both aspects, TMS techniques show their usefulness in the assessment of movement disorders.

Introduction: Quantification of motor functions of patients with dystonic syndromes treated by chronic high frequency stimulation of the internal globulus pallidus is a challenge., Objective: Through a series of clinical examples this paper shows that kinematic analysis of movements in dystonic syndromes treated by deep brain stimulation (DBS) is a complement to clinical evaluation. In addition, it provides valuable information for early detection of improvement or impairment of movements associated with modifications of stimulation parameters., Method: Thirteen dystonic patients and eleven reference subjects completed three tests (i.e., rest: lying supine; posture: standing with arms held in front (at shoulder height); and alternative movements: bimanual finger-to-nose test). These tests were recorded with an electromagnetic system quantifying movement kinematics (position) in three-dimensional space., Results: From the recorded data, several indices were developed and provided a quantitative evaluation of movements during each test. In addition, a clinical evaluation (BMFDRS) was also completed. No correlation between clinical and kinematic evaluations was found., Conclusion: It is shown that kinematic analysis is a useful complement of clinical evaluation and can assist clinicians in monitoring the evolution of movements in dystonic patients treated by DBS in a simple, reliable and valid fashion.

Laryngeal dystonia alters phonatory and respiratory functions in ways that may differ according to the various clinical forms. Spasmodic dysphonia, however, is the most usual clinical consequence; it is characterized either and most often by an raucous, strained, jerky voice and dotted by vocal short stops, or, more rarely, by a breathed, murmured hardly audible voice. Laryngeal dystonia may also express itself by a permanent inspiratory dyspnea witch will increase with effort. The authors describe the principal diagnostic data with are provided essentially by laryngeo-video-fibroscopy and laryngeal electromyography. Treatment of laryngeal dystonia by botulinium toxin is spectacularly efficient, with 66.7 to 100p.100 of good results in literature. Injection techniques are described as well as combined surgical treatments. In adductor spasmodic dysphonia and permanent inspiratory dyspnea, each thyro-arytenoids muscles are injected with 20 to 40 Dysport units or 5 to 10 Botox units, bilaterally; in abductor spasmodic dysphonia, we inject uni or bilaterally, 60 to 80 Dysport units or 15 to 20 Botox units in each posterior crico-arytenoïds muscles. Endoscopic or external laryngeal surgery is proposed to improve functional results when the effects of botulinium toxin injection are disappointing.

Ablative functional neurosurgery constituted during the first half of the 20th century the main treatment of advanced forms of Parkinson's disease. The surgical procedure was spectacularly efficient on tremor, but sometimes complications were not totally regressive and even more severe when surgery was bilateral, this leading to neurocognitive deficits or to speech problems. This, associated to the efficiency of levodopa, was at the origin of the almost total disappearance of this type of surgery during the '60s until the eighties. The rebirth of functional neurosurgery, necessitated by the appearance of dyskinesias, was possible in most part because of the development of techniques with a lower morbidity, such as high frequency stimulation (HFS). This was initially applied to the thalamic ventral intermedius nucleus VIM, and the low morbidity of the method has been demonstrated by the possibility to operate a large number of patients bilaterally without complication. The demonstration that the pallidal target, which had been abandoned during the '50s because of its low efficiency on the triad of symptoms of Parkinson's disease, was selectively efficient on dyskinesias, led naturally to apply HFS to this target. In 1990, the demonstration in the field of fundamental research of the role of the subthalamic nucleus as a key element of regulation of movement, suggested to register this nucleus into the list of targets, despite the risk of hemiballism that this structure presents when it is lesioned by haemorrhage, because of the good tolerance of HFS as a surgical method. This target quickly showed its remarkable efficiency on all symptoms of Parkinson's disease. Because of the reduction of the doses of dopaminergic treatments which were allowed, this target had also the capacity to reduce, indirectly, the intensity of dyskinesias. If the efficiency of the method is nowadays demonstrated as well as the stability on the long term of its results, the mechanism is still mostly not understood. Moreover the physiopathogenic hypothesis suggests the possibility of a neuroprotective effect of the stimulation, which still needs to be clearly established at the experimental level as well as at the level of clinical applications.

Dystonia can be considered either as a symptom, or as a disease. An initial classification of dystonia can be made according to the localization and the severity of the spasms or the associated movement disorders such as myoclonus. A second classification differentiates idiopathic dystonia and secondary dystonia. Personnel medical history, familial cases, neurological symptoms such as pyramidal, cerebellar, oculomotor signs are helpful clues in the diagnosis strategy. Drugs, botulinum toxin, physiotherapy are often combined symptomatic treatment regardless of the cause of dystonia.

Dystonia is characterised by purposeless muscle contractions, and can be expressed in many clinical forms, those involving the head and neck may cause problems with phonation, respiration or deglutition. The authors describe the various treatment options, both therapeutic, medical, rehabilitative and surgical.

The botulinum toxin is a highly potent neurotoxin, used since several years in the treatment of the focal musculary dystonias. We define the laryngeal dystonia as a clinical entity, which is represented by a spasmodic dysphonia or an inspiratory dyspnea without dysphonia, related to a specific dystonia of the thyroarytenoid muscles. The laryngeal functional exploration (i.e. fibroscopy, videostroboscopy, acoustic analysis, computerized voice analysis), the neurological and electrophysiological assessment allow to make diagnosis and evaluation of the therapeutical results of this rare laryngeal neurologic disease which was relatively misunderstood until now. There are several clinical types of spasmodic dysphonia: adductor form (with a jerky voice, pitch beaks, vocal arrests and pneumophonatory incoordination); abductor form (with a breathy voice of very low intensity) and mixed types which can be difficult to identify. Since 1989, we have treated 55 laryngeal dystonias with local intra-muscular botulinum toxin injection: 48 spasmodic dysphonia and 7 inspiratory dyspnea without dysphonia, with hyperactivity of the thyroaryténoïd muscles. We present our therapeutical protocol and results which are good in 87% of cases.

Injections of botulinum toxin into the main cervical muscles responsible for abnormal posture and movements in spasmodic torticollis reduced pain and attenuated dystonia for a period of 2 months on average. After several sessions 9 out of 36 patients (25 p. 100) felt they had improved by at least 50 percent, 16 (44 p.100) by 50 to 75 percent, and 6 (17 p. 100) by more than 75 percent. There were six failures.