M. Simonetta-Moreau

Apomorphine effect on pain threshold in Parkinson's disease: a clinical and positron emission tomography study.

Patients with Parkinsons disease (PD) frequently experience pain that could be in part due to central modification of nociception. In this randomized controlled double blind study, we compared the effect of apomorphine versus placebo on pain thresholds and pain‐induced cerebral activity in 25 patients with PD. Subjective pain threshold (using thermal stimulation, thermotest), objective pain threshold (nociceptive flexion reflex), and cerebral activity (H  215 O PET) during noxious and innocuous stimulations were performed. Neither subjective nor objective pain thresholds nor pain activation profile were modified by apomorphine compared with placebo in 25 PD patients. Apomorphine has no effect on pain processing in PD. We suggest that other monoamine systems than dopaminergic system could be involved.

Deep brain stimulation of the subthalamic nucleus improves pain in Parkinson's disease

BACKGROUND In Parkinsons disease (PD), chronic pain is a common symptom which markedly affects the quality of life. Some physiological arguments proposed that Deep Brain Stimulation of the Subthalamic Nucleus (STN-DBS) could improve pain in PD. METHODS We investigated in 58 PD patients the effect of STN-DBS on pain using the short McGill Pain Questionnaire and other pain parameters such as the Bodily discomfort subscore of the Parkinsons disease Questionnaire 39 and the Unified Parkinsons Disease Rating Scale section II (UPDRS II) item 17. RESULTS All pain scores were significantly improved 12 months after STN-DBS. This improvement was not correlated with motor improvement, depression scores or L-Dopa reduction. CONCLUSIONS STN-DBS induced a substantial beneficial effect on pain in PD, independently of its motor effects and mood status of patients.

Anodal tDCS Combined With Radial Nerve Stimulation Promotes Hand Motor Recovery in the Acute Phase After Ischemic Stroke

Background and Objective. The question of the best therapeutic window in which noninvasive brain stimulation (NIBS) could potentiate the plastic changes for motor recovery after a stroke is still unresolved. Most of the previous NIBS studies included patients in the chronic phase of recovery and very few in the subacute or acute phase. We investigated the effect of transcranial direct current stimulation (tDCS) combined with repetitive peripheral nerve stimulation (rPNS) on the time course of motor recovery in the acute phase after a stroke. Methods. Twenty patients enrolled within the first few days after a stroke were randomized in 2 parallel groups: one receiving 5 consecutive daily sessions of anodal tDCS over the ipsilesional motor cortex in association with rPNS and the other receiving the same rPNS combined with sham tDCS. Motor performance (primary endpoint: Jebsen and Taylor Hand Function Test [JHFT]) and transcranial magnetic stimulation cortical excitability measures were obtained at baseline (D1), at the end of the treatment (D5), and at 2 and 4 weeks’ follow-up (D15 and D30). Results. The time course of motor recovery of the 2 groups of patients was different and positively influenced by the intervention (Group × Time interaction P = .01). The amount of improvement on the JHFT was greater at D15 and D30 in the anodal tDCS group than in the sham group. Conclusion. These results show that early cortical neuromodulation with anodal tDCS combined with rPNS can promote motor hand recovery and that the benefit is still present 1 month after the stroke.

Does abnormal interhemispheric inhibition play a role in mirror dystonia

The presence of mirror dystonia (dystonic movement induced by a specific task performed by the unaffected hand) in the dominant hand of writers cramp patients when the nondominant hand is moved suggests an abnormal interaction between the 2 hemispheres. In this study we compare the level of interhemispheric inhibition (IHI) in 2 groups of patients with writers cramp, one with the presence of a mirror dystonia and the other without as well as a control group. The level of bidirectional IHI was measured in wrist muscles with dual‐site transcranial magnetic stimulation with a 10‐millisecond (short IHI) and a 40‐millisecond (long IHI) interstimulus interval during rest and while holding a pen in 9 patients with mirror dystonia 7 without mirror dystonia, and 13 controls. The group of patients without mirror dystonia did not differ from the controls in their IHI level. In contrast, IHI was significantly decreased in the group of patients with mirror dystonia in comparison with the group without mirror dystonia and the controls in both wrist muscles of both the dystonic and unaffected hand whatever the resting or active condition (P = 0.001). The decrease of IHI level in the group of patients with mirror dystonia was negatively correlated with the severity and the duration of the disease: the weaker the level of IHI, the more severe was the disease and the longer its duration. Interhemispheric inhibition disturbances are most likely involved in the occurrence of mirror dystonia. This bilateral deficient inhibition further suggests the involvement of the unaffected hemisphere in the pathophysiology of unilateral dystonia.

Imagerie fonctionnelle cérébrale et prise en charge thérapeutique de l'aphasie : orthophonie et stimulation magnétique transcrânienne répétitive

Functional imaging has provided new evidence of the neurobiological impact of the treatment of aphasia, including speech therapy, through the alteration of the activated language neural network. In such a way, speech therapy has proved its impact. The role of each hemisphere is still very unclear. Some of the authors link the left-lateralisation of activations to the therapeutic improvement of language and the right-activated network to a maladaptative strategy, whereas others consider the latter as a useful compensatory network for speech disorders. Repetitive trans-cranial magnetic stimulation (rTMS), first used to determine cortical activity, is now used to directly interfere with cerebral activity. In the years to come, rTMS should be developed as an adjuvant therapy for aphasia.Functional imaging has provided new evidence of the neurobiological impact of the treatment of aphasia, including speech therapy, through the alteration of the activated language neural network. In such a way, speech therapy has proved its impact. The role of each hemisphere is still very unclear. Some of the authors link the left-lateralisation of activations to the therapeutic improvement of language and the right-activated network to a maladaptative strategy, whereas others consider the latter as a useful compensatory network for speech disorders. Repetitive trans-cranial magnetic stimulation (rTMS), first used to determine cortical activity, is now used to directly interfere with cerebral activity. In the years to come, rTMS should be developed as an adjuvant therapy for aphasia.

C - 12 Tremblement rubral lié à l’effet de masse d’un cavernome mésencéphale pontique

Introduction Le tremblement rubral (TR) est la consequence d’une interruption de la voie cerebello rubro thalamique. Nous rapportons un TR lie a un possible effet de masse d’un cavernome de la jonction mesencephalo pontique. Observations Une femme de 71 ans, sans antecedent notable consultait en 2006 en raison d’un tremblement. Un scanner cerebral realise en 1990 avait retrouve une lesion vasculaire mesencephalo-pontique gauche non etiquetee et de decouverte fortuite chez une patiente alors asymptomatique d’un point de vue neurologique. En 2004, elle constatait l’apparition progressive d’un tremblement et d’une instabilite d’aggravation progressive. En 2006, l’examen retrouvait un tremblement mixte du membre superieur droit, de repos s’accentuant nettement lors du maintien d’attitude et a l’action. Ce tremblement lent, distal etait associe a une posture dystonique du membre superieur droit. Il existait une ataxie moderee pouvant s’integrer dans le cadre d’un syndrome cerebelleux statique. Le reste de l’examen neurologique etait normal. L’IRM revelait une lesion d’allure cavernomateuse, de la jonction mesencephalo-pontique gauche qui avait augmente de volume entre 1990 et 2006, sans signe recent de saignement. Les benzodiazepines, la primidone, et les betabloquants restent sans effet. Un Datscan, un test a la levodopa et un enregistrement electrophysiologique du tremblement ont ete realises. Discussion Le cavernome interesse les noyaux rouges et sous thalamique, le pedoncule cerebelleux controlateral, et peut expliquer ce tremblement. l’augmentation de volume du cavernome et l’absence de saignement plaident pour un effet compressif des voies cerebello-dentato-rubro-thalamiques. L’association dystonie-tremblement rubral n’est pas frequemment decrite. Conclusion Le tremblement rubral peut etre associe a une posture dystonique et sa physiopathologie peut etre liee a un phenomene compressif.