scholarly journals Targeting the posterior subthalamic area for essential tremor: proposal for MRI-based anatomical landmarks

2019 ◽  
Vol 131 (3) ◽  
pp. 820-827 ◽  
Author(s):  
Andreas Nowacki ◽  
Ines Debove ◽  
Frédéric Rossi ◽  
Janine Ai Schlaeppi ◽  
Katrin Petermann ◽  
...  
Keyword(s):  
Essential Tremor ◽  
Rating Scale ◽  
Diffusion Tensor ◽  
Red Nucleus ◽  
Target Position ◽  
Postoperative Outcome ◽  
Clinical Effectiveness ◽  
Zona Incerta ◽  
Target Point ◽  
Anatomical Landmarks

OBJECTIVEDeep brain stimulation (DBS) of the posterior subthalamic area (PSA) is an alternative to thalamic DBS for the treatment of essential tremor (ET). The dentato-rubro-thalamic tract (DRTT) has recently been proposed as the anatomical substrate underlying effective stimulation. For clinical purposes, depiction of the DRTT mainly depends on diffusion tensor imaging (DTI)–based tractography, which has some drawbacks. The objective of this study was to present an accurate targeting strategy for DBS of the PSA based on anatomical landmarks visible on MRI and to evaluate clinical effectiveness.METHODSThe authors performed a retrospective cohort study of a prospective series of 11 ET patients undergoing bilateral DBS of the PSA. The subthalamic nucleus and red nucleus served as anatomical landmarks to define the target point within the adjacent PSA on 3-T T2-weighted MRI. Stimulating contact (SC) positions with reference to the midcommissural point were analyzed and projected onto the stereotactic atlas of Morel. Postoperative outcome assessment after 6 and 12 months was based on change in Tremor Rating Scale (TRS) scores.RESULTSActual target position corresponded to the intended target based on anatomical landmarks depicted on MRI. The total TRS score was reduced (improved) from 47.2 ± 15.7 to 21.3 ± 10.7 (p < 0.001). No severe complication occurred. The mean SC position projected onto the PSA at the margin of the cerebellothalamic fascicle and the zona incerta.CONCLUSIONSTargeting of the PSA based on anatomical landmarks representable on MRI is reliable and leads to accurate lead placement as well as good long-term clinical outcome.

scholarly journals MR-guided focused ultrasound cerebellothalamic tractotomy for chronic therapy-resistant essential tremor: anatomical target reappraisal and clinical results

2020 ◽  
pp. 1-10 ◽  
Author(s):  
Marc N. Gallay ◽  
David Moser ◽  
Daniel Jeanmonod
Keyword(s):  
Essential Tremor ◽  
Focused Ultrasound ◽  
Rating Scale ◽  
Hand Function ◽  
Red Nucleus ◽  
Posterior Part ◽  
Clinical Results ◽  
Effective Treatment Option ◽  
Chronic Therapy ◽  
The Mean

OBJECTIVEIn addition to the well-recognized ventral intermediate nucleus (Vim) thalamotomy for the treatment of chronic therapy-resistant essential tremor (ET), an alternative approach targeting the posterior part of the subthalamus was proposed in the 1960s and early 1970s and then was reactualized as cerebellothalamic tractotomy (CTT) with the advent of MR-guided focused ultrasound (MRgFUS) surgery. The goal of this study was to improve target coverage and thus efficacy (i.e., tremor control and its consistency). The authors undertook a histological reappraisal of the CTT target and proposed a targeting strategy of the MRgFUS CTT based on 1) the MR visualization of the center of the red nucleus and 2) the application of preplanned target subunits realized with short sonications under thermal dose control. This study was aimed at demonstrating the efficacy and risk profile of this approach against chronic therapy-resistant ET.METHODSTen consecutive patients suffering from chronic therapy-resistant ET benefited from a unilateral MRgFUS CTT and were followed over the course of 1 year. Primary endpoints were subjective tremor relief, Clinical Rating Scale for Tremor (CRST) score, activities of daily living (ADL) score, and the hand function (HF) scores HF16 and HF32. Histological reappraisal of the target led the authors to propose a standardized targeting protocol for MRgFUS CTT. Thermal doses for 18 and 240 cumulative equivalent minutes at 43°C were calculated and correlated with intraoperative and 2 days postoperative T2-weighted MR images.RESULTSThe mean ± SD for the baseline CRST score was 48 ± 12; the score was 16 ± 7 at 3 months, and 17 ± 8 at 1 year. The mean tremor relief rated by the patients for the operated side was 95% after 2 days, 96% at 3 months, and 93% at 1 year. The mean HF16 was 11.0 ± 2.1 at baseline, 0.7 ± 0.7 at 3 months, and 0.8 ± 0.9 at 1 year (93% mean reduction). The minimum reduction for the HF16 at 1 year was 78%. There was a 51% reduction of the mean ADL score at 1 year. There was no bleeding or infection. Gait difficulties, only detectable on tandem gait, were increased in 3 patients and reduced in 2 patients at 1 year. There was no dysarthria.CONCLUSIONSThe authors’ results suggest that MRgFUS CTT is a very effective treatment option for therapy-resistant ET.

Electrical stimulation of the posterior subthalamic area for the treatment of intractable proximal tremor

2003 ◽  
Vol 99 (4) ◽  
pp. 708-715 ◽  
Author(s):  
Jun-ichi Murata ◽  
Mayumi Kitagawa ◽  
Haruo Uesugi ◽  
Hisatoshi Saito ◽  
Yoshinobu Iwasaki ◽  
...  
Keyword(s):  
White Matter ◽  
Rating Scale ◽  
Red Nucleus ◽  
Posterior Part ◽  
Zona Incerta ◽  
Content Type ◽  
Unilateral Stimulation ◽  
The 1960S ◽  
Fine Print ◽  
Stimulation Of

Object. Tremors, including its proximal component, are often refractory to standard thalamic surgery. In the 1960s the posterior part of the subthalamic white matter was reported to be a promising target in treating various forms of tremor, but was also found to be associated with adverse effects. Advances involving a less invasive method, that is, deep brain stimulation (DBS), has led to a reappraisal of this target. Methods. Eight patients with severe essential tremor involving the proximal arm were treated using unilateral stimulation of the posterior part of the subthalamic white matter. The tentative target was situated in the area lateral to the red nucleus and posteromedial to the subthalamic nucleus. Macrostimulation was used to find the optimal site to suppress tremor. Through a quadripolar DBS lead, somatosensory evoked potentials (SSEPs) were recorded. Improvement of tremor was evaluated based on a modified clinical tremor rating scale. Anatomical locations of all contacts were assessed using stereotactic guidance and represented on the Schaltenbrand—Wahren atlas. Conclusions. A characteristic diphasic pattern of SSEPs reaffirmed the electrophysiological endorsement of this target. Tremors, both proximal and distal, were remarkably improved in all patients. The rate of improvement, as indicated by the total tremor score, was a mean of 81%. Axial tremors in the legs and head were also improved. Most of the contacts associated with remarkable improvement were located in the posterior part of the subthalamic white matter (the zona incerta and prelemniscal radiation). Neither major complications nor neurological deterioration was observed. The authors concluded that DBS of the posterior part of the subthalamic white matter together with SSEP recording is a safe and effective method to ameliorate severe intractable tremors.

scholarly journals Selecting the most effective DBS contact in essential tremor patients based on individual tractography

2020 ◽  
Author(s):  
Jan Niklas Petry-Schmelzer ◽  
Till A. Dembek ◽  
Julia K. Steffen ◽  
Hannah Jergas ◽  
Haidar S. Dafsari ◽  
...  
Keyword(s):  
Essential Tremor ◽  
Clinical Effect ◽  
Diffusion Tensor ◽  
Clinical Effectiveness ◽  
Clinical Testing ◽  
Group Level ◽  
Linear Mixed Effects ◽  
Test Stimulation ◽  
The Individual ◽  
Deep Brain

AbstractPostoperative choice of the most effective DBS contact in patients with essential tremor (ET) so far relies on lengthy clinical testing. It has been shown that the postoperative effectiveness of DBS contacts depends on the distance to the dentatorubrothalamic tract (DRTT). Here, we investigated whether the most effective DBS contact could be determined from the stimulation overlap with the individual DRTT. Seven ET patients with bilateral thalamic deep brain stimulation were included retrospectively. Tremor control was assessed contact-wise during test stimulation with 2mA. The individual DRTTs were identified from diffusion tensor imaging. Contacts were ranked by their overlap of the test stimulation with the respective DRTT in relation to their clinical effectiveness. A linear mixed-effects model was calculated to determine the influence of the DRTT-overlap on tremor control. In 92.9 % of the cases, the contact with the best clinical effect was the contact with the highest or second-highest DRTT-overlap. On the group level, the DRTT-overlap explained 26.7% of the variance of the clinical outcome (p<0.001). To conclude, data suggest that the overlap with the DRTT based on individual tractography may serve as a marker to determine the most effective DBS contact in ET patients and reduce burdensome clinical testing in the future.

scholarly journals Selecting the Most Effective DBS Contact in Essential Tremor Patients Based on Individual Tractography

2020 ◽  
Vol 10 (12) ◽  
pp. 1015
Author(s):  
Jan Niklas Petry-Schmelzer ◽  
Till A. Dembek ◽  
Julia K. Steffen ◽  
Hannah Jergas ◽  
Haidar S. Dafsari ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Essential Tremor ◽  
Brain Stimulation ◽  
Diffusion Tensor ◽  
Clinical Effectiveness ◽  
Clinical Testing ◽  
Linear Mixed Effects ◽  
Test Stimulation ◽  
The Individual ◽  
Deep Brain

Postoperative choice of the most effective deep brain stimulation (DBS) contact in patients with essential tremor (ET) so far relies on lengthy clinical testing. Previous studies showed that the postoperative effectiveness of DBS contacts depends on the distance to the dentatorubrothalamic tract (DRTT). Here, we investigated whether the most effective DBS contact could be determined from calculating stimulation overlap with the individual DRTT. Seven ET patients with bilateral thalamic deep brain stimulation were included retrospectively. Tremor control was assessed for each contact during test stimulation with 2mA. Individual DRTTs were identified from diffusion tensor imaging and contacts were ranked by their stimulation overlap with the respective DRTT in relation to their clinical effectiveness. A linear mixed-effects model was calculated to determine the influence of the DRTT overlap on tremor control. In 92.9% of investigated DBS leads, the contact with the best clinical effect was the contact with the highest or second-highest DRTT-overlap. At the group level, the DRTT-overlap explained 26.7% of the variance in the clinical outcomes (p < 0.001). Our data suggest that the overlap with the DRTT based on individual tractography may serve as a marker to determine the most effective DBS contact in ET patients and reduce burdensome clinical testing in the future.

scholarly journals Clinically applicable artificial intelligence system for dental diagnosis with CBCT

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matvey Ezhov ◽  
Maxim Gusarev ◽  
Maria Golitsyna ◽  
Julian M. Yates ◽  
Evgeny Kushnerev ◽  
...  
Keyword(s):  
State Of The Art ◽  
Model Development ◽  
Clinical Effectiveness ◽  
Anatomical Landmarks ◽  
Periapical Lesion ◽  
Artificial Intelligence System ◽  
Intelligence System ◽  
Significant Difference ◽  
Diagnostic Capabilities ◽  
Lesion Localization

AbstractIn this study, a novel AI system based on deep learning methods was evaluated to determine its real-time performance of CBCT imaging diagnosis of anatomical landmarks, pathologies, clinical effectiveness, and safety when used by dentists in a clinical setting. The system consists of 5 modules: ROI-localization-module (segmentation of teeth and jaws), tooth-localization and numeration-module, periodontitis-module, caries-localization-module, and periapical-lesion-localization-module. These modules use CNN based on state-of-the-art architectures. In total, 1346 CBCT scans were used to train the modules. After annotation and model development, the AI system was tested for diagnostic capabilities of the Diagnocat AI system. 24 dentists participated in the clinical evaluation of the system. 30 CBCT scans were examined by two groups of dentists, where one group was aided by Diagnocat and the other was unaided. The results for the overall sensitivity and specificity for aided and unaided groups were calculated as an aggregate of all conditions. The sensitivity values for aided and unaided groups were 0.8537 and 0.7672 while specificity was 0.9672 and 0.9616 respectively. There was a statistically significant difference between the groups (p = 0.032). This study showed that the proposed AI system significantly improved the diagnostic capabilities of dentists.

scholarly journals Thalamic Connectivity in Patients with Essential Tremor Treated with MR Imaging–guided Focused Ultrasound: In Vivo Fiber Tracking by Using Diffusion-Tensor MR Imaging

Radiology ◽  
2014 ◽  
Vol 272 (1) ◽  
pp. 202-209 ◽  
Author(s):  
Max Wintermark ◽  
Diane S. Huss ◽  
Binit B. Shah ◽  
Nicholas Tustison ◽  
T. Jason Druzgal ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Essential Tremor ◽  
Focused Ultrasound ◽  
Diffusion Tensor ◽  
Fiber Tracking ◽  
Diffusion Tensor Mr Imaging

scholarly journals Clinical effectiveness and potential long-term benefits of high-intensity focused ultrasound therapy for patients with adenomyosis

2020 ◽  
Vol 48 (12) ◽  
pp. 030006052097649
Author(s):  
Wei Li ◽  
Jiayu Mao ◽  
Yang Liu ◽  
Ying Zhu ◽  
Xiaojing Li ◽  
...  
Keyword(s):  
High Intensity ◽  
Focused Ultrasound ◽  
Rating Scale ◽  
Numerical Rating Scale ◽  
Clinical Effectiveness ◽  
Treatment Method ◽  
Mean Difference ◽  
High Intensity Focused Ultrasound ◽  
Noninvasive Treatment ◽  
Numerical Rating

Objectives Adenomyosis is a common and refractory disease in gynecology. Preserving the uterus during treatment for adenomyosis remains a problem. High-intensity focused ultrasound (HIFU) is widely used in treatment of solid tumors. This study aimed to analyze patients with adenomyosis who were treated by HIFU and to preliminarily examine the characteristics of patients who are more suitable for HIFU to treat adenomyosis with reliable efficacy. Methods Over 2 years, 67 women who were diagnosed with adenomyosis and treated with HIFU at our gynecology department were included in this study. We investigated outcomes of their symptoms (dysmenorrhea and hypermenorrhea) and the volume of their uterine lesions. We also compared the patients’ clinical profiles. Results The women had a mean follow-up duration of 11.6 ± 0.46 months. In the numerical rating scale, used to assess the degree of dysmenorrhea, the score was significantly lower (mean difference: −1.94, 95% confidence interval: −2.704 to −1.176) 3 months after HIFU treatment compared with before treatment, then it remained stable for 3 to 12 months. Hypermenorrhea was reduced to a certain degree, with a mean difference of −0.54 (−1.01–0.02). Conclusions HIFU is a new noninvasive treatment method for adenomyosis that may help relieve dysmenorrhea.

scholarly journals White matter differences between essential tremor and Parkinson disease

Neurology ◽  
2018 ◽  
Vol 92 (1) ◽  
pp. e30-e39 ◽  
Author(s):  
Meher R. Juttukonda ◽  
Giulia Franco ◽  
Dario J. Englot ◽  
Ya-Chen Lin ◽  
Kalen J. Petersen ◽  
...  
Keyword(s):  
White Matter ◽  
Parkinson Disease ◽  
Essential Tremor ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Superior Cerebellar Peduncle ◽  
Radial Diffusivity ◽  
Cerebellar Peduncles ◽  
Cerebellar Peduncle

ObjectiveTo assess white matter integrity in patients with essential tremor (ET) and Parkinson disease (PD) with moderate to severe motor impairment.MethodsSedated participants with ET (n = 57) or PD (n = 99) underwent diffusion tensor imaging (DTI) and fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity values were computed. White matter tracts were defined using 3 well-described atlases. To determine candidate white matter regions that differ between ET and PD groups, a bootstrapping analysis was applied using the least absolute shrinkage and selection operator. Linear regression was applied to assess magnitude and direction of differences in DTI metrics between ET and PD populations in the candidate regions.ResultsFractional anisotropy values that differentiate ET from PD localize primarily to thalamic and visual-related pathways, while diffusivity differences localized to the cerebellar peduncles. Patients with ET exhibited lower fractional anisotropy values than patients with PD in the lateral geniculate body (p < 0.01), sagittal stratum (p = 0.01), forceps major (p = 0.02), pontine crossing tract (p = 0.03), and retrolenticular internal capsule (p = 0.04). Patients with ET exhibited greater radial diffusivity values than patients with PD in the superior cerebellar peduncle (p < 0.01), middle cerebellar peduncle (p = 0.05), and inferior cerebellar peduncle (p = 0.05).ConclusionsRegionally, distinctive white matter microstructural values in patients with ET localize to the cerebellar peduncles and thalamo-cortical visual pathways. These findings complement recent functional imaging studies in ET but also extend our understanding of putative physiologic features that account for distinctions between ET and PD.

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