A literature review of magnetic resonance imaging sequence advancements in visualizing functional neurosurgery targets

2021 ◽  
pp. 1-14
Author(s):  
Alexandre Boutet ◽  
Aaron Loh ◽  
Clement T. Chow ◽  
Alaa Taha ◽  
Gavin J. B. Elias ◽  
...  

OBJECTIVE Historically, preoperative planning for functional neurosurgery has depended on the indirect localization of target brain structures using visible anatomical landmarks. However, recent technological advances in neuroimaging have permitted marked improvements in MRI-based direct target visualization, allowing for refinement of “first-pass” targeting. The authors reviewed studies relating to direct MRI visualization of the most common functional neurosurgery targets (subthalamic nucleus, globus pallidus, and thalamus) and summarize sequence specifications for the various approaches described in this literature. METHODS The peer-reviewed literature on MRI visualization of the subthalamic nucleus, globus pallidus, and thalamus was obtained by searching MEDLINE. Publications examining direct MRI visualization of these deep brain stimulation targets were included for review. RESULTS A variety of specialized sequences and postprocessing methods for enhanced MRI visualization are in current use. These include susceptibility-based techniques such as quantitative susceptibility mapping, which exploit the amount of tissue iron in target structures, and white matter attenuated inversion recovery, which suppresses the signal from white matter to improve the distinction between gray matter nuclei. However, evidence confirming the superiority of these sequences over indirect targeting with respect to clinical outcome is sparse. Future targeting may utilize information about functional and structural networks, necessitating the use of resting-state functional MRI and diffusion-weighted imaging. CONCLUSIONS Specialized MRI sequences have enabled considerable improvement in the visualization of common deep brain stimulation targets. With further validation of their ability to improve clinical outcomes and advances in imaging techniques, direct visualization of targets may play an increasingly important role in preoperative planning.

2011 ◽  
Vol 115 (5) ◽  
pp. 971-984 ◽  
Author(s):  
Ellen J. L. Brunenberg ◽  
Bram Platel ◽  
Paul A. M. Hofman ◽  
Bart M. ter Haar Romeny ◽  
Veerle Visser-Vandewalle

The authors reviewed 70 publications on MR imaging–based targeting techniques for identifying the subthalamic nucleus (STN) for deep brain stimulation in patients with Parkinson disease. Of these 70 publications, 33 presented quantitatively validated results. There is still no consensus on which targeting technique to use for surgery planning; methods vary greatly between centers. Some groups apply indirect methods involving anatomical landmarks, or atlases incorporating anatomical or functional data. Others perform direct visualization on MR imaging, using T2-weighted spin echo or inversion recovery protocols. The combined studies do not offer a straightforward conclusion on the best targeting protocol. Indirect methods are not patient specific, leading to varying results between cases. On the other hand, direct targeting on MR imaging suffers from lack of contrast within the subthalamic region, resulting in a poor delineation of the STN. These deficiencies result in a need for intraoperative adaptation of the original target based on test stimulation with or without microelectrode recording. It is expected that future advances in MR imaging technology will lead to improvements in direct targeting. The use of new MR imaging modalities such as diffusion MR imaging might even lead to the specific identification of the different functional parts of the STN, such as the dorsolateral sensorimotor part, the target for deep brain stimulation.


Author(s):  
Azari H ◽  

Background: Deep Brain Stimulation (DBS) is regarded as a viable therapeutic choice for Parkinson’s Disease (PD). The two most common sites for DBS are the Subthalamic Nucleus (STN) and Globus Pallidus (GPi). In this study, the clinical effectiveness of these two targets was compared. Methods: A systematic literature search in electronic databases were restricted to English language publications 2010 to 2021. Specified MeSH terms were searched in all databases. Studies that evaluated the Unified Parkinson’s Disease Rating Scale (UPDRS) III were selected by meeting the following criteria: (1) had at least three months follow-up period; (2) compared both GPi and STN DBS; (3) at least five participants in each group; (4) conducted after 2010. Study quality assessment was performed using the Modified Jadad Scale. Results: 3577 potentially relevant articles were identified 3569 were excluded based on title and abstract, duplicate and unsuitable article removal. Eight articles satisfied the inclusion criteria and were scrutinized (458 PD patients). Majority of studies reported no statistically significant between-group difference for improvements in UPDRS III scores. Conclusions: Although there were some results in terms of action tremor, rigidity, and urinary symptoms, which indicated that STN DBS might be a better choice or regarding the adverse effects, GPi seemed better; but it cannot be concluded that one target is superior. Other larger randomized clinical trials with longer follow-up periods and control groups are needed to decide which target is more efficient for stimulation and imposes fewer adverse effects on the patients.


Author(s):  
Chencheng Zhang ◽  
Linbin Wang ◽  
Wei Hu ◽  
Tao Wang ◽  
Yijie Zhao ◽  
...  

Abstract BACKGROUND Subthalamic nucleus (STN) and globus pallidus interna (GPi) are the most effective targets in deep brain stimulation (DBS) treatment for Parkinson disease (PD). However, the individualized selection of targets remains a clinical challenge. OBJECTIVE To combine unilateral STN and contralateral GPi stimulation (STN DBS in one brain hemisphere and GPi DBS in the other) to maximize the clinical advantages of each target while inducing fewer adverse side effects in selected patients with PD because each target has its own clinical effects and risk profiles. METHODS We reviewed the clinical outcomes of 8 patients with idiopathic PD treated with combined unilateral STN and contralateral GPi DBS. Clinical outcome assessments, focusing on motor and nonmotor symptoms, were performed at baseline and 6-mo and 12-mo follow-up. We performed the assessments under the following conditions: medication on and off (bilateral stimulation on and off and unilateral STN stimulation on). RESULTS Patients showed a significant improvement in motor symptoms, as assessed by the Unified Parkinson Disease Rating Scale III (UPDRS-III) and Timed Up-and-Go Test (TUG), in the off-medication/on-stimulation state at 6-mo and 12-mo follow-up. Also, patients reported a better quality of life, and their intake of levodopa was reduced at 12-mo follow-up. In the on-medication condition, bilateral stimulation was associated with an improvement in axial symptoms, with a 64% improvement in measures of gait and falls at 12-mo follow-up. No irreversible adverse side effects were observed. CONCLUSION Our findings suggest that combined unilateral STN and contralateral GPi DBS could offer an effective and well-tolerated DBS treatment for certain PD patients.


2009 ◽  
Vol 256 (8) ◽  
pp. 1321-1329 ◽  
Author(s):  
Laura B. Zahodne ◽  
Michael S. Okun ◽  
Kelly D. Foote ◽  
Hubert H. Fernandez ◽  
Ramon L. Rodriguez ◽  
...  

2021 ◽  
Author(s):  
Hushyar Azari

Abstract Background: Deep brain stimulation (DBS) is regarded as a viable therapeutic choice for Parkinson's disease (PD). The two most common sites for DBS are the subthalamic nucleus (STN) and globus pallidus (GPi). In this study, the clinical effectiveness of these two targets was compared.Methods: A systematic literature search in electronic databases were restricted to English language publications 2010 to 2021. Specified MeSH terms were searched in all databases. Studies that evaluated the Unified Parkinson's Disease Rating Scale (UPDRS) III were selected by meeting the following criteria: (1) had at least three months follow-up period; (2) compared both GPi and STN DBS; (3)at least five participants in each group; (4)conducted after 2010. Study quality assessment was performed using the Modified Jadad Scale.Results: 3577 potentially relevant articles were identified,3569 were excluded based on title and abstract, duplicate and unsuitable article removal. Eight articles satisfied the inclusion criteria and were scrutinized (458 PD patients). Majority of studies reported no statistically significant between-group difference for improvements in UPDRS ш scores.Conclusions: Although there were some results in terms of action tremor, rigidity, and urinary symptoms, which indicated that STN DBS might be a better choice or regarding the adverse effects, GPi seemed better; but it cannot be concluded that one target is superior. Other larger randomized clinical trials with longer follow-up periods and control groups are needed to decide which target is more efficient for stimulation and imposes fewer adverse effects on the patients.


2020 ◽  
Vol 132 (3) ◽  
pp. 721-732 ◽  
Author(s):  
Suzhen Lin ◽  
Yiwen Wu ◽  
Hongxia Li ◽  
Chencheng Zhang ◽  
Tao Wang ◽  
...  

OBJECTIVESurgical procedures involving deep brain stimulation (DBS) of the globus pallidus internus (GPi) or subthalamic nucleus (STN) are well-established treatments for isolated dystonia. However, selection of the best stimulation target remains a matter of debate. The authors’ objective was to compare the effectiveness of DBS of the GPi and the STN in patients with isolated dystonia.METHODSIn this matched retrospective cohort study, the authors searched an institutional database for data on all patients with isolated dystonia who had undergone bilateral implantation of DBS electrodes in either the GPi or STN in the period from January 30, 2014, to June 30, 2017. Standardized assessments of dystonia and health-related quality of life using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) and SF-36 were conducted before and at 1, 6, and 12 months after surgery. No patients were lost to the 6-month follow-up; 5 patients were lost to the 12-month follow-up.RESULTSBoth GPi (14 patients) and STN (16 patients) stimulation produced significant improvement in dystonia and quality of life in all 30 patients found in the database search. At the 1-month follow-up, however, the percentage improvement in the BFMDRS total movement score was significantly (p = 0.01) larger after STN DBS (64%) than after GPi DBS (48%). At the 12-month follow-up, the percentage improvement in the axis subscore was significantly (p = 0.03) larger after GPi DBS (93%) than after STN DBS (83%). Also, the total amount of electrical energy delivered was significantly (p = 0.008) lower with STN DBS than with GPi DBS (124 ± 52 vs 192 ± 65 μJ, respectively).CONCLUSIONSThe GPi and STN are both effective targets in alleviating dystonia and improving quality of life. However, GPi stimulation may be better for patients with axial symptoms. Moreover, STN stimulation may produce a larger clinical response within 1 month after surgery and may have a potential economic advantage in terms of lower battery consumption.


2009 ◽  
Vol 65 (5) ◽  
pp. 586-595 ◽  
Author(s):  
Michael S. Okun ◽  
Hubert H. Fernandez ◽  
Samuel S. Wu ◽  
Lindsey Kirsch-Darrow ◽  
Dawn Bowers ◽  
...  

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