Brain penetration effects of microelectrodes and deep brain stimulation leads in ventral intermediate nucleus stimulation for essential tremor

2010 ◽  
Vol 112 (3) ◽  
pp. 491-496 ◽  
Author(s):  
Takashi Morishita ◽  
Kelly D. Foote ◽  
Samuel S. Wu ◽  
Charles E. Jacobson ◽  
Ramon L. Rodriguez ◽  
...  

Object Microelectrode recording (MER) and macrostimulation (test stimulation) are used to refine the optimal deep brain stimulation (DBS) lead placement within the operative setting. It is well known that there can be a microlesion effect with microelectrode trajectories and DBS insertion. The aim of this study was to determine the impact of intraoperative MER and lead placement on tremor severity in a cohort of patients with essential tremor. Methods Consecutive patients with essential tremor undergoing unilateral DBS (ventral intermediate nucleus stimulation) for medication-refractory tremor were evaluated. Tremor severity was measured at 5 time points utilizing a modified Tremor Rating Scale: 1) immediately before MER; 2) immediately after MER; 3) immediately after lead implantation; 4) 6 months after DBS implantation in the off-DBS condition; and 5) 6 months after implantation in the on-DBS condition. To investigate the impact of the MER and DBS lead placement, Wilcoxon signed-rank tests were applied to test changes in tremor severity scores over the surgical course. In addition, a generalized linear mixed model including factors that potentially influenced the impact of the microlesion was also used for analysis. Results Nineteen patients were evaluated. Improvement was noted in the total modified Tremor Rating Scale, postural, and action tremor scores (p < 0.05) as a result of MER and DBS lead placement. The improvements observed following lead placement were similar in magnitude to what was observed in the chronically programmed clinic setting parameters at 6 months after lead implantation. Improvement in tremor severity was maintained over time even in the off-DBS condition at 6 months, which was supportive of a prolonged microlesion effect. The number of macrostimulation passes, the number of MER passes, and disease duration were not related to the change in tremor severity score over time. Conclusions Immediate improvement in postural and intention tremors may result from MER and DBS lead placement in patients undergoing DBS for essential tremor. This improvement could be a predictor of successful DBS lead placement at 6 months. Clinicians rating patients in the operating room should be aware of these effects and should consider using rating scales before and after lead placement to take these effects into account when evaluating outcome in and out of the operating room.

Neurology ◽  
2020 ◽  
Vol 94 (10) ◽  
pp. e1073-e1084 ◽  
Author(s):  
Takashi Tsuboi ◽  
Zakia Jabarkheel ◽  
Pamela R. Zeilman ◽  
Matthew J. Barabas ◽  
Kelly D. Foote ◽  
...  

ObjectiveTo assess longitudinal tremor outcomes with ventral intermediate nucleus deep brain stimulation (VIM DBS) in patients with dystonic tremor (DT) and to compare with DBS outcomes in essential tremor (ET).MethodsWe retrospectively investigated VIM DBS outcomes for 163 patients followed at our center diagnosed with either DT or ET. The Fahn-Tolosa-Marin tremor rating scale (TRS) was used to assess change in tremor and activities of daily living (ADL) at 6 months, 1 year, 2–3 years, 4–5 years, and ≥6 years after surgery.ResultsTwenty-six patients with DT and 97 patients with ET were analyzed. Compared to preoperative baseline, there were significant improvements in TRS motor up to 4–5 years (52.2%; p = 0.032) but this did not reach statistical significance at ≥6 years (46.0%, p = 0.063) in DT, which was comparable to the outcomes in ET. While the improvements in the upper extremity tremor, head tremor, and axial tremor were also comparable between DT and ET throughout the follow-up, the ADL improvements in DT were lost at 2–3 years follow-up.ConclusionOverall, tremor control with VIM DBS in DT and ET was comparable and remained sustained at long term likely related to intervention at the final common node in the pathologic tremor network. However, the long-term ADL improvements in DT were not sustained, possibly due to inadequate control of concomitant dystonia symptoms. These findings from a large cohort of DT indicate that VIM targeting is reasonable if the tremor is considerably more disabling than the dystonic features.Classification of evidenceThis study provides Class IV evidence that VIM DBS improves tremor in patients with DT or ET.


Brain ◽  
2021 ◽  
Author(s):  
Takashi Tsuboi ◽  
Joshua K Wong ◽  
Robert S Eisinger ◽  
Lela Okromelidze ◽  
Mathew R Burns ◽  
...  

Abstract The pathophysiology of dystonic tremor and essential tremor remains partially understood. In patients with medication-refractory dystonic tremor or essential tremor, deep brain stimulation (DBS) targeting the thalamus or posterior subthalamic area has evolved into a promising treatment option. However, the optimal DBS targets for these disorders remains unknown. This retrospective study explored the optimal targets for DBS in essential tremor and dystonic tremor using a combination of volumes of tissue activated estimation and functional and structural connectivity analyses. We included 20 patients with dystonic tremor who underwent unilateral thalamic DBS, along with a matched cohort of 20 patients with essential tremor DBS. Tremor severity was assessed preoperatively and approximately 6 months after DBS implantation using the Fahn-Tolosa-Marin Tremor Rating Scale. The tremor-suppressing effects of DBS were estimated using the percentage improvement in the unilateral tremor-rating scale score contralateral to the side of implantation. The optimal stimulation region, based on the cluster centre of gravity for peak contralateral motor score improvement, for essential tremor was located in the ventral intermediate nucleus region and for dystonic tremor in the ventralis oralis posterior nucleus region along the ventral intermediate nucleus/ventralis oralis posterior nucleus border (4 mm anterior and 3 mm superior to that for essential tremor). Both disorders showed similar functional connectivity patterns: a positive correlation between tremor improvement and involvement of the primary sensorimotor, secondary motor and associative prefrontal regions. Tremor improvement, however, was tightly correlated with the primary sensorimotor regions in essential tremor, whereas in dystonic tremor, the correlation was tighter with the premotor and prefrontal regions. The dentato-rubro-thalamic tract, comprising the decussating and non-decussating fibres, significantly correlated with tremor improvement in both dystonic and essential tremor. In contrast, the pallidothalamic tracts, which primarily project to the ventralis oralis posterior nucleus region, significantly correlated with tremor improvement only in dystonic tremor. Our findings support the hypothesis that the pathophysiology underpinning dystonic tremor involves both the cerebello-thalamo-cortical network and the basal ganglia-thalamo-cortical network. Further our data suggest that the pathophysiology of essential tremor is primarily attributable to the abnormalities within the cerebello-thalamo-cortical network. We conclude that the ventral intermediate nucleus/ventralis oralis posterior nucleus border and ventral intermediate nucleus region may be a reasonable DBS target for patients with medication-refractory dystonic tremor and essential tremor, respectively. Uncovering the pathophysiology of these disorders may in the future aid in further improving DBS outcomes.


Neurology ◽  
2017 ◽  
Vol 89 (13) ◽  
pp. 1416-1423 ◽  
Author(s):  
Rubens Gisbert Cury ◽  
Valerie Fraix ◽  
Anna Castrioto ◽  
Maricely Ambar Pérez Fernández ◽  
Paul Krack ◽  
...  

Objective:To report on the long-term outcomes of deep brain stimulation (DBS) of the thalamic ventral intermediate nucleus (VIM) in Parkinson disease (PD), essential tremor (ET), and dystonic tremor.Methods:One hundred fifty-nine patients with PD, ET, and dystonia underwent VIM DBS due to refractory tremor at the Grenoble University Hospital. The primary outcome was a change in the tremor scores at 1 year after surgery and at the latest follow-up (21 years). Secondary outcomes included the relationship between tremor score reduction over time and the active contact position. Tremor scores (Unified Parkinson's Disease Rating Scale-III, items 20 and 21; Fahn, Tolosa, Marin Tremor Rating Scale) and the coordinates of the active contacts were recorded.Results:Ninety-eight patients were included. Patients with PD and ET had sustained improvement in tremor with VIM stimulation (mean improvement, 70% and 66% at 1 year; 63% and 48% beyond 10 years, respectively; p < 0.05). There was no significant loss of stimulation benefit over time (p > 0.05). Patients with dystonia exhibited a moderate response at 1-year follow-up (41% tremor improvement, p = 0.027), which was not sustained after 5 years (30% improvement, p = 0.109). The more dorsal active contacts' coordinates in the right lead were related to a better outcome 1 year after surgery (p = 0.029). During the whole follow-up, forty-eight patients (49%) experienced minor side effects, whereas 2 (2.0%) had serious events (brain hemorrhage and infection).Conclusions:VIM DBS is an effective long-term (beyond 10 years) treatment for tremor in PD and ET. Effects on dystonic tremor were modest and transient.Classification of evidence:This provides Class IV evidence. It is an observational study.


2021 ◽  
Author(s):  
Maarten Bot ◽  
Anne-Fleur van Rootselaari ◽  
Vincent Odekerken ◽  
Joke Dijk ◽  
Rob M A de Bie ◽  
...  

Abstract BACKGROUND Dentato-rubro-thalamic tract (DRT) deep brain stimulation (DBS) suppresses tremor in essential tremor (ET) patients. However, DRT depiction through tractography can vary depending on the included brain regions. Moreover, it is unclear which section of the DRT is optimal for DBS. OBJECTIVE To evaluate deterministic DRT tractography and tremor control in DBS for ET. METHODS After DBS surgery, DRT tractography was conducted in 37 trajectories (20 ET patients). Per trajectory, 5 different DRT depictions with various regions of interest (ROI) were constructed. Comparison resulted in a DRT depiction with highest correspondence to intraoperative tremor control. This DRT depiction was subsequently used for evaluation of short-term postoperative adverse and beneficial effects. RESULTS Postoperative optimized DRT tractography employing the ROI motor cortex, posterior subthalamic area (PSA), and ipsilateral superior cerebellar peduncle and dentate nucleus best corresponded with intraoperative trajectories (92%) and active DBS contacts (93%) showing optimal tremor control. DRT tractography employing a red nucleus or ventral intermediate nucleus of the thalamus (VIM) ROI often resulted in a more medial course. Optimal stimulation was located in the section between VIM and PSA. CONCLUSION This optimized deterministic DRT tractography strongly correlates with optimal tremor control. This technique is readily implementable for prospective evaluation in DBS target planning for ET.


2020 ◽  
Vol 10 (12) ◽  
pp. 925
Author(s):  
Christian Iorio-Morin ◽  
Anton Fomenko ◽  
Suneil K. Kalia

Tremor is a prevalent symptom associated with multiple conditions, including essential tremor (ET), Parkinson’s disease (PD), multiple sclerosis (MS), stroke and trauma. The surgical management of tremor evolved from stereotactic lesions to deep-brain stimulation (DBS), which allowed safe and reversible interference with specific neural networks. This paper reviews the current literature on DBS for tremor, starting with a detailed discussion of current tremor targets (ventral intermediate nucleus of the thalamus (Vim), prelemniscal radiations (Raprl), caudal zona incerta (Zi), thalamus (Vo) and subthalamic nucleus (STN)) and continuing with a discussion of results obtained when performing DBS in the various aforementioned tremor syndromes. Future directions for DBS research are then briefly discussed.


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