Deep brain stimulation of the ventral intermediate nucleus in patients with essential tremor: Stimulation below intercommissural line is more efficient but equally effective as stimulation above (original) (raw)
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Deep brain stimulation in the posterior subthalamic area in the treatment of essential tremor
Movement Disorders, 2010
To evaluate the posterior subthalamic area (PSA) as a target for deep brain stimulation (DBS) in the treatment of essential tremor (ET). The ventral intermediate nucleus of the thalamus is the traditional target for DBS in the treatment of ET. Recent studies have presented beneficial effects of DBS in the PSA in the treatment of tremor. Twenty-one patients with ET were included in this study. All patients were evaluated before and 1 year after surgery, on and off stimulation, using the essential tremor rating scale (ETRS). A marked microlesional effect was noticed in 83%, in some cases obviating the need for electrical stimulation for many months. The total ETRS was reduced from 46.2 at baseline to 18.7 (60%). Item 5/6 (tremor of the upper extremity) was improved from 6.2 to 0.3 (95%), and items 11 to 14 (hand function) from 9.7 to 1.3 (87%) concerning the contralateral hand. Activities of daily living were improved by 66%. No severe complication occurred. Eight patients presented a postoperative mild dysphasia that regressed within days to weeks. DBS in the PSA resulted in a marked reduction of tremor.
Acta Neurochirurgica
The ventro-lateral thalamus is the stereotactic target of choice for severe intention tremor. Nevertheless, the optimal target area has remained controversial, and targeting of the subthalamic area has been suggested to be superior. Eleven patients with disabling intention tremor of different etiology (essential tremor (n = 8), multiple sclerosis (n = 2) and one with, spinocerebellar ataxia) were implanted bilaterally with DBS electrodes targeted to the ventro-lateral thalamus using micro-recording and micro-stimulation. Among five tracks explored in parallel optimal tracks were chosen for permanent electrode implantation. Postoperative tremor suppression elicited by individual electrode contacts was quantified using a lateralised tremor rating scale at least 3 months (in most patients >1 year) after implantation. The position of electrode contacts was determined retrospectively from stereotactic X-ray exams and by correlation of pre- and postoperative MRI. In all patients, DBS suppressed intention tremor markedly. On average, tremor on the left and right side of the body was improved by 68% (+/-19; standard deviation) and 73% (+/-21), respectively. In most patients, distal electrode contacts located in the subthalamic area proved to be more effective than proximal contacts in the ventro-lateral thalamus. In stereotactic coordinates, the optimal site was located 12.7 mm (+/-1.4; mean +/- standard deviation) lateral, 7.0 (+/-1.6) mm posterior, and 1.5 (+/-2.0) mm ventral to the mid-commissural point. In general, the best contacts could be selected for permanent stimulation. Nevertheless, in some instances, more proximal contacts had to be chosen because of adverse effects (paraesthesiae, dysarthria, gait ataxia) which were more pronounced with bilateral stimulation resulting in slightly less tremor suppression on the left and right side of body (63 +/- 18 and 68 +/- 19%, respectively). Direct comparison of different stimulation sites in individual patients revealed that DBS in the subthalamic area is more effective in suppressing pharmacoresistant intention tremor than the ventro-lateral thalamus proper. Anatomical structures possibly involved in tremor suppression include cerebello-thalamic projections, the prelemniscal radiation, and the zona incerta.
Post subthalamic area deep brain stimulation for tremors: a mini-review
Translational neurodegeneration, 2012
Deep brain stimulation (DBS) in the thalamic ventrointermediate nucleus (VIM) is the traditional target for the surgical treatment of pharmacologically refractory essential tremor or parkinsonian tremor. Studies in recent years on DBS in posterior subthalamic area (PSA), including the zona incerta and the prelemniscal radiation, have shown promising results in tremor suppression, particularly for those tremors difficult to be well controlled by VIM DBS, such as the proximal postural tremor, distal intention tremor and some cerebellar outflow tremor in various diseases including essential tremor and multiple sclerosis. The adverse effect profile of the PSA DBS is mild and transient, without lasting or striking dysarthria, disequilibrium or tolerance, in contrast to VIM DBS, particularly bilateral DBS. However, the studies on PSA DBS so far are still limited, with a handful of studies on bilateral PSA, and a short follow up duration compared to VIM. More studies are needed for direct ...
Deep brain stimulation of the posterior subthalamic area in the treatment of tremor
Acta Neurochirurgica, 2009
Background Several studies have described lesional therapy in the posterior subthalamic area (PSA) in the treatment of various movement disorders. Recently, some publications have illustrated the effect of deep brain stimulation (DBS) in this area in patients with Parkinson's disease, essential tremor, MS-tremor, and other forms of tremor. Even though the clinical series is small, the reported benefits prompted us to explore DBS in this area in the treatment of tremor. Method Five patients with tremor were operated using unilateral DBS of the PSA. Two patients had dystonic tremor, one primary writing tremor, one cerebellar tremor and the other neuropathic tremor. All patients were assessed before and 1 year after surgery using items 5 and 6 (tremor of the upper extremity), 11-14 (hand function), and when appropriate item 10 (handwriting) from the essential tremor rating scale. Findings The mean improvement on stimulation after 1 year was 87%. A pronounced and sustained microlesional effect was seen in several of the patients, and while the mean improvement off stimulation was 56% the reduction in the three patients with the most pronounced effect was 89%. The two patients with dystonic tremor did also become free of the dystonic symptoms and pain in the treated arm. No severe complication occurred.
Acta Neurochirurgica, 2011
Background Deep brain stimulation (DBS) is an effective treatment for essential tremor (ET). Currently the ventrolateral thalamus is the target of choice, but the posterior subthalamic area (PSA), including the caudal zona incerta (cZi), has demonstrated promising results, and the subthalamic nucleus (STN) has been suggested as a third alternative. The objective of the current study was to evaluate the effect of STN DBS in ET and to compare this to cZi DBS. Methods Four patients with ET were implanted with two ipsilateral electrodes, one in the STN and one in the cZi. All contacts were evaluated concerning the acute effect on tremor, and the effect of chronic DBS in either target was analyzed. Results STN and cZi both proved to be potent targets for DBS in ET. DBS in the cZi was more efficient, since the same degree of tremor reduction could here be achieved at lower energy consumption. Three patients became tremorfree in the treated hand with either STN or cZi DBS, while the fourth had a minor residual tremor after stimulation in either target. Conclusion In this limited material, STN DBS was demonstrated to be an efficient treatment for ET, even though cZi DBS was more efficient. The STN may be an alternative target in the treatment of ET, pending further investigations to decide on the relative merits of the different targets.
Thalamic Deep Brain Stimulation in Essential Tremor Plus Is as Effective as in Essential Tremor
Brain Sciences
The new essential tremor (ET) classification defined ET-plus (ET-p) as an ET subgroup with additional neurological signs besides action tremor. While deep brain stimulation (DBS) is effective in ET, there are no studies specifically addressing DBS effects in ET-p. 44 patients with medication-refractory ET and thalamic/subthalamic DBS implanted at our center were postoperatively classified into ET and ET-p according to preoperative documentation. Tremor suppression with DBS (stimulation ON vs. preoperative baseline and vs. stimulation OFF), measured via the Fahn–Tolosa–Marin tremor rating scale (TRS), stimulation parameters, and the location of active contacts were compared between patients classified as ET and ET-p. TRS scores at baseline were higher in ET-p. ET-p patients showed comparable tremor reduction as patients with ET, albeit higher stimulation parameters were needed in ET-p. Active electrode contacts were located more dorsally in ET-p of uncertain reason. Our data show tha...
Stimulation of the subthalamic region for essential tremor
Journal of Neurosurgery, 2004
Object. The goal of this study was to determine the safety and efficacy of bilateral subthalamic region stimulation in the treatment of essential tremor (ET). Methods. Following induction of general anesthesia, four patients with disabling tremor that had proved to be refractory to pharmacotherapy underwent magnetic resonance imaging—guided deep brain stimulation (DBS) of the bilateral subthalamic region. Tremor was assessed by applying the Fahn-Tolosa-Marín Tremor Rating Scale at baseline and again at the 12-month follow-up examination. Following surgery the total tremor score improved by 80.1% (from a baseline mean score of 63 ± 15.1 to a score of 11.8 ± 3.9 at 12 months postoperatively). There was a significant improvement (p < 0.0001) in the mean tremor score of the upper limb (postural and action component) from a baseline score of 3 ± 0.9 to a score of 0.5 ± 0.5 at 12 months postoperatively. In two patients with Score 4 head tremor complete arrest of the tremor was observed...
Thalamic Deep Brain Stimulation for Essential Tremor: Relation of Lead Location to Outcome
Neurosurgery, 2004
OBJECTIVE: Thalamic deep brain stimulation (DBS) is commonly used to treat essential tremor, but the optimal lead location within the thalamus has not been systematically evaluated. We examined the relation of lead location to clinical outcome in a series of essential tremor patients treated by thalamic DBS. METHODS: Fifty-seven leads in 37 patients were studied. Lead locations were measured by postoperative magnetic resonance imaging. Contralateral arm tremor was assessed in the DBS-on and DBS-off states using the Fahn-Tolosa-Marin tremor rating scale, with a mean follow-up of 26 months. Lead locations were statistically correlated, using analysis of variance, with percent improvement in tremor resulting from DBS activation. RESULTS: Improvement in tremor score was significantly correlated with lead location in both the anteroposterior and lateral dimensions. In the plane of the commissures, the optimal electrode location was determined statistically to be 6.3 mm anterior to the po...