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Parkinson Disease: HELP
Articles by Clement Hamani
Based on 40 articles published since 2010
(Why 40 articles?)
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Between 2010 and 2020, C. Hamani wrote the following 40 articles about Parkinson Disease.
 
+ Citations + Abstracts
Pages: 1 · 2
1 Guideline Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Subthalamic Nucleus and Globus Pallidus Internus Deep Brain Stimulation for the Treatment of Patients With Parkinson's Disease: Executive Summary. 2018

Rughani, Anand / Schwalb, Jason M / Sidiropoulos, Christos / Pilitsis, Julie / Ramirez-Zamora, Adolfo / Sweet, Jennifer A / Mittal, Sandeep / Espay, Alberto J / Martinez, Jorge Gonzalez / Abosch, Aviva / Eskandar, Emad / Gross, Robert / Alterman, Ron / Hamani, Clement. ·Neuroscience Institute, Maine Medical Center, Portland, Maine. · Department of Neurosurgery, Henry Ford Medical Gr-oup, West Bloomfield, Michigan. · De-partment of Neurology and Ophthal-mology, Michigan State University, Michigan. · Departments of Neuroscience and Experimental Therapeutics and of Neurosurgery, Albany Medical College, Albany, New York. · Center for Movement Disorders and Neurorestoration, Gain-esville, Florida. · Department of Neuro-surgery, University Hospitals Cleveland Medical Center, Cleveland, Ohio. · De-partment of Neurosurgery, Wayne State University, Detroit, Michigan. · James J. and Joan A. Gardner Center for Parkinson Disease and Movement Disorders, University of Cincinnati, Cincinnati, Ohio. · Neurological Institute, Cleveland Clinic, Cleveland, Ohio. · Department of Neurosurgery, University of Colorado School of Medicine, Aurora, Colorado. · Department of Neurological Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts. · Department of Neu-rosurgery, Emory University, Atlanta, Georgia. · Division of Neurosurgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massa-chusetts. · Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. ·Neurosurgery · Pubmed #29538685.

ABSTRACT: QUESTION 1: Is bilateral subthalamic nucleus deep brain stimulation (STN DBS) more, less, or as effective as bilateral globus pallidus internus deep brain stimulation (GPi DBS) in treating motor symptoms of Parkinson's disease, as measured by improvements in Unified Parkinson's Disease Rating Scale, part III (UPDRS-III) scores? RECOMMENDATION: Given that bilateral STN DBS is at least as effective as bilateral GPi DBS in treating motor symptoms of Parkinson's disease (as measured by improvements in UPDRS-III scores), consideration can be given to the selection of either target in patients undergoing surgery to treat motor symptoms. (Level I). QUESTION 2: Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in allowing reduction of dopaminergic medication in Parkinson's disease? RECOMMENDATION: When the main goal of surgery is reduction of dopaminergic medications in a patient with Parkinson's disease, then bilateral STN DBS should be performed instead of GPi DBS. (Level I). QUESTION 3: Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in treating dyskinesias associated with Parkinson's disease? RECOMMENDATION: There is insufficient evidence to make a generalizable recommendation regarding the target selection for reduction of dyskinesias. However, when the reduction of medication is not anticipated and there is a goal to reduce the severity of "on" medication dyskinesias, the GPi should be targeted. (Level I). QUESTION 4: Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in improving quality of life measures in Parkinson's disease? RECOMMENDATION: When considering improvements in quality of life in a patient undergoing DBS for Parkinson's disease, there is no basis to recommend bilateral DBS in 1 target over the other. (Level I). QUESTION 5: Is bilateral STN DBS associated with greater, lesser, or a similar impact on neurocognitive function than bilateral GPi DBS in Parkinson disease? RECOMMENDATION: If there is significant concern about cognitive decline, particularly in regards to processing speed and working memory in a patient undergoing DBS, then the clinician should consider using GPi DBS rather than STN DBS, while taking into consideration other goals of surgery. (Level I). QUESTION 6: Is bilateral STN DBS associated with a higher, lower, or similar risk of mood disturbance than GPi DBS in Parkinson's disease? RECOMMENDATION: If there is significant concern about the risk of depression in a patient undergoing DBS, then the clinician should consider using pallidal rather than STN stimulation, while taking into consideration other goals of surgery. (Level I). QUESTION 7: Is bilateral STN DBS associated with a higher, lower, or similar risk of adverse events compared to GPi DBS in Parkinson's disease? RECOMMENDATION: There is insufficient evidence to recommend bilateral DBS in 1 target over the other in order to minimize the risk of surgical adverse events.  The full guideline can be found at: https://www.cns.org/guidelines/deep-brain-stimulation-parkinsons-disease.

2 Editorial MRIgFUS in tremor-dominant PD does not lead to substantial cognitive adverse events. 2018

Zervos, Thomas M / Hamani, Clement / Schwalb, Jason M. ·From the Department of Neurosurgery (T.M.Z., J.M.S.), Henry Ford Medical Group, Detroit, MI · and Harquail Centre for Neuromodulation (C.H.), Division of Neurosurgery, Sunnybrook Health Science Centre, University of Toronto, Canada. ·Neurology · Pubmed #30158164.

ABSTRACT: -- No abstract --

3 Editorial Preventing Parkinson disease by vagotomy: Fact or fiction? 2017

Borghammer, Per / Hamani, Clement. ·From the Department of Nuclear Medicine and PET Centre (P.B.), Aarhus University Hospital, Denmark · Division of Neurosurgery (C.H.), Toronto Western Hospital, University of Toronto · and Department of Neuroimaging (C.H.), Centre for Addiction and Mental Health, Campbell Family Mental Health Research Institute, Toronto, Ontario, Canada. ·Neurology · Pubmed #28446643.

ABSTRACT: -- No abstract --

4 Editorial Deep brain stimulation and memory. 2013

Hamani, Clement / Nobrega, José N. · ·Expert Rev Med Devices · Pubmed #23895068.

ABSTRACT: -- No abstract --

5 Review Spinal Cord Stimulation for Freezing of Gait: From Bench to Bedside. 2019

Fonoff, Erich Talamoni / de Lima-Pardini, Andrea C / Coelho, Daniel Boari / Monaco, Bernardo Assumpção / Machado, Birajara / Pinto de Souza, Carolina / Dos Santos Ghilardi, Maria Gabriela / Hamani, Clement. ·Hospital Israelita Albert Einstein, São Paulo, Brazil. · Department of Neurology, University of São Paulo, São Paulo, Brazil. · Laboratory of Integrative Motor Behaviour, Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada. · Human Motor Systems Laboratory, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil. · Biomedical Engineering, Federal University of ABC, Santo André, Brazil. · Neurosurgery, Association for Assistance of Disabled Children (AACD), São Paulo, Brazil. · Division of Neurosurgery, Harquail Centre for Neuromodulation, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada. ·Front Neurol · Pubmed #31507514.

ABSTRACT: Spinal cord stimulation (SCS) has been used for the treatment of chronic pain for nearly five decades. With a high degree of efficacy and a low incidence of adverse events, it is now considered to be a suitable therapeutic alternative in most guidelines. Experimental studies suggest that SCS may also be used as a therapy for motor and gait dysfunction in parkinsonian states. The most common and disabling gait dysfunction in patients with Parkinson's disease (PD) is freezing of gait (FoG). We review the evolution of SCS for gait disorders from bench to bedside and discuss potential mechanisms of action, neural substrates, and clinical outcomes.

6 Review Is there a role for MR-guided focused ultrasound in Parkinson's disease? 2018

Meng, Ying / Voisin, Mathew R / Suppiah, Suganth / Kalia, Suneil K / Kalia, Lorraine V / Hamani, Clement / Lipsman, Nir. ·Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, ON, Canada. · Department of Surgery, University of Toronto, Toronto, ON, Canada. · Division of Neurosurgery, Toronto Western Hospital, Toronto, ON, Canada. · Krembil Research Institute, Toronto Western Hospital, University Health Network, 60 Leonard Ave Toronto, ON, Canada. · Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Division of Neurology, Department of Medicine, Toronto Western Hospital, University Health Network, Toronto, ON, Canada. · Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada. · Division of Neurology, Department of Medicine, University of Toronto, Toronto, ON, Canada. ·Mov Disord · Pubmed #29476631.

ABSTRACT: -- No abstract --

7 Review Subthalamic Nucleus Deep Brain Stimulation: Basic Concepts and Novel Perspectives. 2017

Hamani, Clement / Florence, Gerson / Heinsen, Helmut / Plantinga, Birgit R / Temel, Yasin / Uludag, Kamil / Alho, Eduardo / Teixeira, Manoel J / Amaro, Edson / Fonoff, Erich T. ·Division of Neurosurgery Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada. · Division of Neuroimaging, Centre for Addiction and Mental Health, Toronto, Ontario, Canada. · Division of Neurosurgery, Department of Neurology, University of São Paulo Medical School, São Paulo, Brazil. · Department of Radiology, University of São Paulo Medical School, São Paulo, Brazil. · Department of Psychiatry, Psychosomatics and Psychotherapy, Center of Mental Health, University Clinic of Würzburg, Würzburg, Germany. · Department of Biomedical Image Analysis, Eindhoven University of Technology, Eindhoven, The Netherlands. · Department of Neurosurgery, Maastricht University Medical Center, Maastricht, The Netherlands. · Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands. · Department of Cognitive Neuroscience, Maastricht University, Maastricht, The Netherlands. · Instituto de Ensino e Pesquisa Hospital Sírio-Libanês, São Paulo, Brazil. ·eNeuro · Pubmed #28966978.

ABSTRACT: Over the last decades, extensive basic and clinical knowledge has been acquired on the use of subthalamic nucleus (STN) deep brain stimulation (DBS) for Parkinson's disease (PD). It is now clear that mechanisms involved in the effects of this therapy are far more complex than previously anticipated. At frequencies commonly used in clinical practice, neural elements may be excited or inhibited and novel dynamic states of equilibrium are reached. Electrode contacts used for chronic DBS in PD are placed near the dorsal border of the nucleus, a highly cellular region. DBS may thus exert its effects by modulating these cells, hyperdirect projections from motor cortical areas, afferent and efferent fibers to the motor STN. Advancements in neuroimaging techniques may allow us to identify these structures optimizing surgical targeting. In this review, we provide an update on mechanisms and the neural elements modulated by STN DBS.

8 Review Speech and language adverse effects after thalamotomy and deep brain stimulation in patients with movement disorders: A meta-analysis. 2017

Alomar, Soha / King, Nicolas K K / Tam, Joseph / Bari, Ausaf A / Hamani, Clement / Lozano, Andres M. ·King Abdulaziz University, Department of Surgery, Division of Neurosurgery, King Abdulaziz University Hospital, Jeddah, Saudi Arabia. · University of Toronto, Department of Surgery, Division of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada. · Department of Neurosurgery, National Neuroscience Institute, Singapore. · University of California Los Angeles, Department of Neurosurgery, Los Angeles, California, USA. ·Mov Disord · Pubmed #28124434.

ABSTRACT: BACKGROUND: The thalamus has been a surgical target for the treatment of various movement disorders. Commonly used therapeutic modalities include ablative and nonablative procedures. A major clinical side effect of thalamic surgery is the appearance of speech problems. OBJECTIVE: This review summarizes the data on the development of speech problems after thalamic surgery. METHODS: A systematic review and meta-analysis was performed using nine databases, including Medline, Web of Science, and Cochrane Library. We also checked for articles by searching citing and cited articles. We retrieved studies between 1960 and September 2014. RESULTS: Of a total of 2,320 patients, 19.8% (confidence interval: 14.8-25.9) had speech difficulty after thalamotomy. Speech difficulty occurred in 15% (confidence interval: 9.8-22.2) of those treated with a unilaterally and 40.6% (confidence interval: 29.5-52.8) of those treated bilaterally. Speech impairment was noticed 2- to 3-fold more commonly after left-sided procedures (40.7% vs. 15.2%). Of the 572 patients that underwent DBS, 19.4% (confidence interval: 13.1-27.8) experienced speech difficulty. Subgroup analysis revealed that this complication occurs in 10.2% (confidence interval: 7.4-13.9) of patients treated unilaterally and 34.6% (confidence interval: 21.6-50.4) treated bilaterally. After thalamotomy, the risk was higher in Parkinson's patients compared to patients with essential tremor: 19.8% versus 4.5% in the unilateral group and 42.5% versus 13.9% in the bilateral group. After DBS, this rate was higher in essential tremor patients. CONCLUSION: Both lesioning and stimulation thalamic surgery produce adverse effects on speech. Left-sided and bilateral procedures are approximately 3-fold more likely to cause speech difficulty. This effect was higher after thalamotomy compared to DBS. In the thalamotomy group, the risk was higher in Parkinson's patients, whereas in the DBS group it was higher in patients with essential tremor. Understanding the pathophysiology of speech disturbance after thalamic procedures is a priority. © 2017 International Parkinson and Movement Disorder Society.

9 Review Deep Brain Stimulation Target Selection for Parkinson's Disease. 2017

Honey, Christopher R / Hamani, Clement / Kalia, Suneil K / Sankar, Tejas / Picillo, Marina / Munhoz, Renato P / Fasano, Alfonso / Panisset, Michel. ·1Division of Neurosurgery,University of British Columbia,Vancouver,British Columbia. · 2Research Imaging Centre,Centre for Addiction and Mental Health,Toronto. · 3Department of Surgery,Division of Neurosurgery,University of Toronto. · 5Division of Neurosurgery,Walter C. MacKenzie Health Sciences Centre,University of Alberta,Edmonton,Alberta. · 4Morton and Gloria Shulman Movement Disorders Centre and the Edmond J. Safra Program in Parkinson's Disease,Toronto Western Hospital,University Health Network,Toronto,Ontario. · 6Division of Neurology,Department of Medicine,Hôpital Notre-Dame,University of Montreal Health Centre,Montréal,Québec,Canada. ·Can J Neurol Sci · Pubmed #26976064.

ABSTRACT: During the "DBS Canada Day" symposium held in Toronto July 4-5, 2014, the scientific committee invited experts to discuss three main questions on target selection for deep brain stimulation (DBS) of patients with Parkinson's disease (PD). First, is the subthalamic nucleus (STN) or the globus pallidus internus (GPi) the ideal target? In summary, both targets are equally effective in improving the motor symptoms of PD. STN allows a greater medications reduction, while GPi exerts a direct antidyskinetic effect. Second, are there further potential targets? Ventral intermediate nucleus DBS has significant long-term benefit for tremor control but insufficiently addresses other motor features of PD. DBS in the posterior subthalamic area also reduces tremor. The pedunculopontine nucleus remains an investigational target. Third, should DBS for PD be performed unilaterally, bilaterally or staged? Unilateral STN DBS can be proposed to asymmetric patients. There is no evidence that a staged bilateral approach reduces the incidence of DBS-related adverse events.

10 Review Pedunculopontine Nucleus Region Deep Brain Stimulation in Parkinson Disease: Surgical Techniques, Side Effects, and Postoperative Imaging. 2016

Hamani, Clement / Lozano, Andres M / Mazzone, Paolo A M / Moro, Elena / Hutchison, William / Silburn, Peter A / Zrinzo, Ludvic / Alam, Mesbah / Goetz, Laurent / Pereira, Erlick / Rughani, Anand / Thevathasan, Wesley / Aziz, Tipu / Bloem, Bastiaan R / Brown, Peter / Chabardes, Stephan / Coyne, Terry / Foote, Kelly / Garcia-Rill, Edgar / Hirsch, Etienne C / Okun, Michael S / Krauss, Joachim K. ·Division of Neurosurgery, Toronto Western Hospital, University of Toronto, Toronto, Ont., Canada. ·Stereotact Funct Neurosurg · Pubmed #27728909.

ABSTRACT: The pedunculopontine nucleus (PPN) region has received considerable attention in clinical studies as a target for deep brain stimulation (DBS) in Parkinson disease. These studies have yielded variable results with an overall impression of improvement in falls and freezing in many but not all patients treated. We evaluated the available data on the surgical anatomy and terminology of the PPN region in a companion paper. Here we focus on issues concerning surgical technique, imaging, and early side effects of surgery. The aim of this paper was to gain more insight into the reasoning for choosing specific techniques and to discuss shortcomings of available studies. Our data demonstrate the wide range in almost all fields which were investigated. There are a number of important challenges to be resolved, such as identification of the optimal target, the choice of the surgical approach to optimize electrode placement, the impact on the outcome of specific surgical techniques, the reliability of intraoperative confirmation of the target, and methodological differences in postoperative validation of the electrode position. There is considerable variability both within and across groups, the overall experience with PPN DBS is still limited, and there is a lack of controlled trials. Despite these challenges, the procedure seems to provide benefit to selected patients and appears to be relatively safe. One important limitation in comparing studies from different centers and analyzing outcomes is the great variability in targeting and surgical techniques, as shown in our paper. The challenges we identified will be of relevance when designing future studies to better address several controversial issues. We hope that the data we accumulated may facilitate the development of surgical protocols for PPN DBS.

11 Review Pedunculopontine Nucleus Region Deep Brain Stimulation in Parkinson Disease: Surgical Anatomy and Terminology. 2016

Hamani, Clement / Aziz, Tipu / Bloem, Bastiaan R / Brown, Peter / Chabardes, Stephan / Coyne, Terry / Foote, Kelly / Garcia-Rill, Edgar / Hirsch, Etienne C / Lozano, Andres M / Mazzone, Paolo A M / Okun, Michael S / Hutchison, William / Silburn, Peter / Zrinzo, Ludvic / Alam, Mesbah / Goetz, Laurent / Pereira, Erlick / Rughani, Anand / Thevathasan, Wesley / Moro, Elena / Krauss, Joachim K. ·Division of Neurosurgery, Toronto Western Hospital, University of Toronto, Toronto, Ont., Canada. ·Stereotact Funct Neurosurg · Pubmed #27723662.

ABSTRACT: Several lines of evidence over the last few years have been important in ascertaining that the pedunculopontine nucleus (PPN) region could be considered as a potential target for deep brain stimulation (DBS) to treat freezing and other problems as part of a spectrum of gait disorders in Parkinson disease and other akinetic movement disorders. Since the introduction of PPN DBS, a variety of clinical studies have been published. Most indicate improvements in freezing and falls in patients who are severely affected by these problems. The results across patients, however, have been variable, perhaps reflecting patient selection, heterogeneity in target selection and differences in surgical methodology and stimulation settings. Here we outline both the accumulated knowledge and the domains of uncertainty in surgical anatomy and terminology. Specific topics were assigned to groups of experts, and this work was accumulated and reviewed by the executive committee of the working group. Areas of disagreement were discussed and modified accordingly until a consensus could be reached. We demonstrate that both the anatomy and the functional role of the PPN region need further study. The borders of the PPN and of adjacent nuclei differ when different brainstem atlases and atlas slices are compared. It is difficult to delineate precisely the PPN pars dissipata from the nucleus cuneiformis, as these structures partially overlap. This lack of clarity contributes to the difficulty in targeting and determining the exact localization of the electrodes implanted in patients with akinetic gait disorders. Future clinical studies need to consider these issues.

12 Review Optimizing microdialysis for deep brain stimulation. 2016

Lopez, William Omar Contreras / Fonoff, Erich Talamoni / Hamani, Clement / Tierney, Travis S / Alho, Eduardo / Ghilardi, Maria Gabriela dos Santos / Teixeira, Manoel Jacobsen / Martinez, Raquel Chacon Ruiz. ·Department of Neurology, Division of Functional Neurosurgery, Institute of Psychiatry, University of Sao Paulo School of Medicine, Rua Dr. Ovideo Pires de Campos, 785, Cerqueira Cesar, 01308-060, Sao Paulo, Brazil. · Brigham and Women's Hospital, Department of Neurosurgery, 75 Francis Street, Boston, MA, 02115. · Hospital Sirio-Libanes, Instituto de Ensino e Pesquisa, Laboratory of Neuromodulation and Experimental Pain, Rua Professor Daher Cutait, 69 Sao Paulo, SP, 01308-060, Brazil, quelmartinez@yahoo.com.br 55-1. ·Front Biosci (Elite Ed) · Pubmed #26709663.

ABSTRACT: Cerebral microdialysis is a chemical detection method capable of identifying and simultaneously sampling a wide range of substances in the micromilieu of the monitoring probe. The interstitial space of biological tissues and fluids is sampled through a thin fenestrated dialysis catheter inserted into the brain. The technique has been reported in patients with Parkinson's disease. However, the procedure is not widely used by neurosurgeons, possibly owing to unclear indications and poor effective benefits, mostly secondary to significant pitfalls. In spite of the feasibility of microdialysis in humans, many factors can affect the quality of the process. Possible pitfalls include improperly designed probe, probe insertion effects, ineffective perfusion rate, issues to optimize stabilization period, and insufficient volume sample. This article reviews those key technical features necessary for performing microdialysis in humans during deep brain stimulation for Parkinson's Disease.

13 Review Regional anatomy of the pedunculopontine nucleus: relevance for deep brain stimulation. 2013

Fournier-Gosselin, Marie-Pierre / Lipsman, Nir / Saint-Cyr, Jean A / Hamani, Clement / Lozano, Andres M. ·Division of Neurosurgery, Hôpital Notre-Dame, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada. ·Mov Disord · Pubmed #23926071.

ABSTRACT: The pedunculopontine nucleus (PPN) is currently being investigated as a potential deep brain stimulation target to improve gait and posture in Parkinson's disease. This review examines the complex anatomy of the PPN region and suggests a functional mapping of the surrounding nuclei and fiber tracts that may serve as a guide to a more accurate placement of electrodes while avoiding potentially adverse effects. The relationships of the PPN were examined in different human brain atlases. Schematic representations of those structures in the vicinity of the PPN were generated and correlated with their potential stimulation effects. By providing a functional map and representative schematics of the PPN region, we hope to optimize the placement of deep brain stimulation electrodes, thereby maximizing safety and clinical efficacy.

14 Review Deep brain stimulation effects on memory. 2012

Laxton, A W / Sankar, T / Lozano, A M / Hamani, C. ·Division of Neurosurgery, Toronto Western Hospital, University of Toronto, Toronto, Canada. ·J Neurosurg Sci · Pubmed #23111294.

ABSTRACT: As the population of many countries ages, disorders of cognition and memory-such as Alzheimer's Disease (AD) and dementia associated with Parkinson's Disease-will become a major societal burden. At present, few effective medical therapies against these conditions are available. Deep brain stimulation (DBS) may be a potential therapeutic option, because it can directly target and modulate the activity of structures implicated in circuits subserving memory function. In this article, we review the scientific literature to address some of the mechanisms by which DBS may impact memory and cognition. We then summarize the results of recent clinical experience with DBS in AD and Parkinsonian dementia.

15 Review The pedunculopontine nucleus as a target for deep brain stimulation. 2011

Hamani, Clement / Moro, Elena / Lozano, Andres M. ·Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University Health Network, University of Toronto, 399 Bathurst Street WW 4-447, Toronto, ON, M5T2S8, Canada. ·J Neural Transm (Vienna) · Pubmed #21194002.

ABSTRACT: The pedunculopontine nucleus (PPN) is a brain stem locomotive center that is also involved in the processing of sensory and behavioral information. The PPN has been recently proposed as a potential target for the treatment of axial symptoms in Parkinson's disease (PD). To date, results of the first series of PD patients treated with PPN deep brain stimulation (DBS) have shown promising results. In this article, we review some of the basic aspects of the PPN as a target and the outcome of the recently published clinical trials.

16 Review Deep brain stimulation in clinical practice and in animal models. 2010

Hamani, C / Nobrega, J N / Lozano, A M. ·Division of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada. Clement.Hamani@uhn.on.ca ·Clin Pharmacol Ther · Pubmed #20720537.

ABSTRACT: -- No abstract --

17 Review Basal ganglia physiology and deep brain stimulation. 2010

Lozano, Andres M / Snyder, Brian J / Hamani, Clement / Hutchison, William D / Dostrovsky, Jonathan O. ·Division of Neurosurgery, Toronto Western Hospital, University of Toronto, UHN, Toronto, Ontario, Canada. lozano@uhnres.utoronto.ca ·Mov Disord · Pubmed #20187251.

ABSTRACT: Despite improvements in anatomic imaging of the basal ganglia, microelectrode recording is still an invaluable tool in locating appropriate targets for neurosurgical intervention. These recording also provide an unparalleled opportunity to study the pathophysiological aspects of diseases. This article reviews the principles of microelectrode recording in functional neurosurgery and discusses the pathologic neurophysiologic findings commonly encountered. It also highlights some of the potential mechanisms of action of both dopaminergic drugs and deep brain stimulation. In addition we review the recent work on pedunculopontine nucleus neurophysiology and trials of deep brain stimulation in that region for gait disturbances in Parkinson's disease.

18 Clinical Trial Effects of spinal cord stimulation on postural control in Parkinson's disease patients with freezing of gait. 2018

de Lima-Pardini, Andrea Cristina / Coelho, Daniel Boari / Souza, Carolina Pinto / Souza, Carolina Oliveira / Ghilardi, Maria Gabriela Dos Santos / Garcia, Tiago / Voos, Mariana / Milosevic, Matija / Hamani, Clement / Teixeira, Luis Augusto / Fonoff, Erich Talamoni. ·Centre of Mathematics, Computation and Cognition, Federal University of ABC, São Paulo, Brazil. · Human Motor Systems Laboratory, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil. · Biomedical Engineering, Federal University of ABC, São Paulo, Brazil. · Department of Neurology, University of São Paulo Medical School, São Paulo, Brazil. · Department of Physical Therapy, Speech and Occupational Therapy, School of Medicine, University of São Paulo, São Paulo, Brazil. · Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan. · Division of Neurosurgery, Sunnybrook Research Institute, Harquail Centre for Neuromodulation, University of Toronto, Toronto, Canada. · Division of Neurosurgery, Toronto Western Hospital, University of Toronto, Toronto, Canada. ·Elife · Pubmed #30070204.

ABSTRACT: Freezing of gait (FoG) in Parkinson's disease (PD) is an incapacitating transient phenomenon, followed by continuous postural disorders. Spinal cord stimulation (SCS) is a promising intervention for FoG in patients with PD, however, its effects on distinct domains of postural control is not well known. The aim of this study is to assess the effects of SCS on FoG and distinct domains of postural control. Four patients with FoG were implanted with SCS systems in the upper thoracic spine. Anticipatory postural adjustment (APA), reactive postural responses, gait and FoG were biomechanically assessed. In general, the results showed that SCS improved FoG and APA. However, SCS failed to improve reactive postural responses. SCS seems to influence cortical motor circuits, involving the supplementary motor area. On the other hand, reactive posture control to external perturbation that mainly relies on neuronal circuitries involving the brainstem and spinal cord, is less influenced by SCS.

19 Clinical Trial Spinal cord stimulation improves gait in patients with Parkinson's disease previously treated with deep brain stimulation. 2017

Pinto de Souza, Carolina / Hamani, Clement / Oliveira Souza, Carolina / Lopez Contreras, William Omar / Dos Santos Ghilardi, Maria Gabriela / Cury, Rubens Gisbert / Reis Barbosa, Egberto / Jacobsen Teixeira, Manoel / Talamoni Fonoff, Erich. ·Division of Functional Neurosurgery of Institute of Psychiatry, Department of Neurology, University of São Paulo Medical School, São Paulo, Brazil. · Movement Disorders Section, Department of Neurology, Hospital das Clínicas, University of São Paulo Medical School, São Paulo, Brazil. ·Mov Disord · Pubmed #27862267.

ABSTRACT: BACKGROUND: Deep brain stimulation and levodopatherapy ameliorate motor manifestations in Parkinson's disease, but their effects on axial signs are not sustained in the long term. OBJECTIVES: The objective of this study was to investigate the safety and efficacy of spinal cord stimulation on gait disturbance in advanced Parkinson's disease. METHODS: A total of 4 Parkinson's disease patients who experienced significant postural instability and gait disturbance years after chronic subthalamic stimulation were treated with spinal cord stimulation at 300 Hz. Timed-Up-GO and 20-meter-walk tests, UPDRS III, freezing of gait questionnaire, and quality-of-life scores were measured at 6 months and compared to baseline values. Blinded assessments to measure performance in the Timed-Up-GO and 20-meter-walk tests were carried out during sham stimulation at 300 Hz and 60 Hz. RESULTS: Patients treated with spinal cord stimulation had approximately 50% to 65% improvement in gait measurements and 35% to 45% in UPDRS III and quality-of-life scores. During blinded evaluations, significant improvements in the Timed-Up-GO and 20-meter-walk tests were only recorded at 300 Hz. CONCLUSION: Spinal cord stimulation at 300 Hz was well tolerated and led to a significant improvement in gait. © 2016 International Parkinson and Movement Disorder Society.

20 Article Unraveling the Role of Astrocytes in Subthalamic Nucleus Deep Brain Stimulation in a Parkinson's Disease Rat Model. 2020

Campos, Ana Carolina Pinheiro / Kikuchi, Daniel Seicho / Paschoa, Amanda Faure Nardini / Kuroki, Mayra Akemi / Fonoff, Erich Talamoni / Hamani, Clement / Pagano, Rosana Lima / Hernandes, Marina Sorrentino. ·Division of Neuroscience, Hospital Sírio-Libanês, São Paulo, SP, 01308-060, Brazil. · Department of Medicine, Emory University, Atlanta, GA, 30322, USA. · Division of Neurosurgery, Department of Neurology, University of São Paulo Medical School, São Paulo, 01246-903, Brazil. · Sunnybrook Health Research Institute, Harquail Centre for Neuromodulation, Toronto, ON, M4N 3M5, Canada. · Division of Neuroscience, Hospital Sírio-Libanês, São Paulo, SP, 01308-060, Brazil. rosana.lpagano@hsl.org.br. ·Cell Mol Neurobiol · Pubmed #31939008.

ABSTRACT: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective therapeutic strategy for motor symptoms of Parkinson's disease (PD) when L-DOPA therapy induces disabling side effects. Classical inflammatory activation of glial cells is well established in PD, contributing to the progressive neurodegenerative state; however, the role of DBS in regulating the inflammatory response remains largely unknown. To understand the involvement of astrocytes in the mechanisms of action of DBS, we evaluated the effect of STN-DBS in regulating motor symptoms, astrocyte reactivity, and cytokine expression in a 6-OHDA-induced PD rat model. To mimic in vivo DBS, we investigate the effect of high-frequency stimulation (HFS) in cultured astrocytes regulating cytokine induction and NF-κB activation. We found that STN-DBS improved motor impairment, induced astrocytic hyperplasia, and reversed increased IFN-γ and IL-10 levels in the globus pallidus (GP) of lesioned rats. Moreover, HFS activated astrocytes and prevented TNF-α-induced increase of monocyte chemoattractant protein-1 (MCP-1) and NF-κB activation in vitro. Our results indicate that DBS/HFS may act as a regulator of the inflammatory response in PD states, attenuating classical activation of astrocytes and cytokine induction, potentially through its ability to regulate NF-κB activation. These findings may help us understand the role of astrocyte signaling in HFS, highlighting its possible relationship with the effectiveness of DBS in neurodegenerative disorders.

21 Article Tractography-based targeting of the ventral intermediate nucleus: accuracy and clinical utility in MRgFUS thalamotomy. 2019

Ranjan, Manish / Elias, Gavin J B / Boutet, Alexandre / Zhong, Jidan / Chu, Powell / Germann, Jurgen / Devenyi, Gabriel A / Chakravarty, M Mallar / Fasano, Alfonso / Hynynen, Kullervo / Lipsman, Nir / Hamani, Clement / Kucharczyk, Walter / Schwartz, Michael L / Lozano, Andres M / Hodaie, Mojgan. ·1University Health Network, Toronto. · 2Krembil Brain Institute, Toronto. · 3Joint Department of Medical Imaging, University of Toronto, Ontario. · 4Cerebral Imaging Center, Douglas Mental Health University, McGill University; Departments of. · 5Psychiatry and. · 6Biological and Biomedical Engineering, McGill University, Montreal, Quebec. · 7The Edmond J. Safra Program in Parkinson's Disease and Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Division of Neurology, University of Toronto. · 8Sunnybrook Research Institute, Sunnybrook Health Sciences Center, University of Toronto. · 9Department of Medical Biophysics, University of Toronto. · 10Institute of Biomaterials and Biomedical Engineering, University of Toronto. · 11Division of Neurosurgery, Sunnybrook Health Sciences Center, University of Toronto; and. · 12Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Center, University of Toronto, Ontario, Canada. ·J Neurosurg · Pubmed #31561221.

ABSTRACT: OBJECTIVE: Tractography-based targeting of the thalamic ventral intermediate nucleus (T-VIM) is a novel method conferring patient-specific selection of VIM coordinates for tremor surgery; however, its accuracy and clinical utility in magnetic resonance imaging-guided focused ultrasound (MRgFUS) thalamotomy compared to conventional indirect targeting has not been specifically addressed. This retrospective study sought to compare the treatment locations and potential adverse effect profiles of T-VIM with indirect targeting in a large cohort of MRgFUS thalamotomy patients. METHODS: T-VIM was performed using diffusion tractography outlining the pyramidal and medial lemniscus tracts in 43 MRgFUS thalamotomy patients. T-VIM coordinates were compared with the indirect treatment coordinates used in the procedure. Thalamotomy lesions were delineated on postoperative T1-weighted images and displaced ("translated") by the anteroposterior and mediolateral difference between T-VIM and treatment coordinates. Both translated and actual lesions were normalized to standard space and subsequently overlaid with areas previously reported to be associated with an increased risk of motor and sensory adverse effects when lesioned during MRgFUS thalamotomy. RESULTS: T-VIM coordinates were 2.18 mm anterior and 1.82 mm medial to the "final" indirect treatment coordinates. Translated lesions lay more squarely within the boundaries of the VIM compared to nontranslated lesions and showed significantly less overlap with areas associated with sensory adverse effects. Translated lesions overlapped less with areas associated with motor adverse effects; however, this difference was not significant. CONCLUSIONS: T-VIM leads to the selection of more anterior and medial coordinates than the conventional indirect methods. Lesions moved toward these anteromedial coordinates avoid areas associated with an increased risk of motor and sensory adverse effects, suggesting that T-VIM may improve clinical outcomes.

22 Article Predictors of deep brain stimulation outcome in tremor patients. 2018

Sandoe, Claire / Krishna, Vibhor / Basha, Diellor / Sammartino, Francesco / Tatsch, Joao / Picillo, Marina / di Biase, Lazzaro / Poon, Yu-Yan / Hamani, Clement / Reddy, Duemani / Munhoz, Renato P / Lozano, Andres M / Hutchison, William D / Fasano, Alfonso. ·Edmond J. Safra Program in Parkinson's Disease and Morton, Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital and Division of Neurology, University of Toronto, Toronto, Ontario, Canada. · Center for Neuromodulation, Department of Neurosurgery, The Ohio State University, Columbus, OH, USA. · Krembil Research Institute, Toronto, Ontario, Canada; Department of Physiology, University of Toronto, Toronto, Ontario, Canada. · Krembil Research Institute, Toronto, Ontario, Canada; Division of Neurosurgery, University of Toronto, Toronto, Ontario, Canada. · Center for Neurodegenerative Diseases (CEMAND), Department of Medicina and Surgery, University of Salerno, Italy. · Neurology Unit, Campus Bio-Medico University of Rome, Rome, Italy. · Division of Neurosurgery, University of Toronto, Toronto, Ontario, Canada. · Edmond J. Safra Program in Parkinson's Disease and Morton, Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital and Division of Neurology, University of Toronto, Toronto, Ontario, Canada; Krembil Research Institute, Toronto, Ontario, Canada. Electronic address: alfonso.fasano@gmail.com. ·Brain Stimul · Pubmed #29330020.

ABSTRACT: BACKGROUND: Deep brain stimulation of the ventro-intermedius nucleus of the thalamus is an established treatment for tremor of differing etiologies but factors that may predict the short- and especially long-term outcome of surgery are still largely unknown. METHODS: We retrospectively investigated the clinical, pharmacological, electrophysiological and anatomical features that might predict the initial response and preservation of benefit in all patients who underwent deep brain stimulation for tremor. Data were collected at the following time points: baseline (preoperative), one-year post-surgery, and most recent visit. Tremor severity was recorded using the Fahn-Tolosa-Marin Tremor Rating Scale and/or the Unified Parkinson's Disease Rating Scale. RESULTS: A total of 52 patients were included in the final analysis: 31 with essential tremor, 15 with cerebellar tremor of different etiologies, and 6 with Parkinson's disease. Long-term success (mean follow-up duration 34.7 months, range 1.7-121.1 months) was reported in 63.5%. Predictors of long-term benefit were: underlying tremor etiology (best outcome in Parkinson's disease, worst outcome in cerebellar tremor); age at surgery (the older the better); baseline tremor severity (the greater the better); lack of response to benzodiazepines; a more anterior electrode placement and single-unit beta power (the greater the better). CONCLUSIONS: Specific patients' features (including single unit beta activity) and electrode locations may predict the short- and long-term benefit of thalamic stimulation for tremor. Future prospective studies enrolling a much larger sample of patients are needed to substantiate the associations detected by this retrospective study.

23 Article Disrupted Nodal and Hub Organization Account for Brain Network Abnormalities in Parkinson's Disease. 2016

Koshimori, Yuko / Cho, Sang-Soo / Criaud, Marion / Christopher, Leigh / Jacobs, Mark / Ghadery, Christine / Coakeley, Sarah / Harris, Madeleine / Mizrahi, Romina / Hamani, Clement / Lang, Anthony E / Houle, Sylvain / Strafella, Antonio P. ·Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, TorontoON, Canada; Division of Brain, Imaging and Behaviour - Systems Neuroscience, Krembil Research Institute, University Health Network, University of Toronto, TorontoON, Canada. · Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto ON, Canada. · Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto ON, Canada. · Morton and Gloria Shulman Movement Disorder Unit & E. J. Safra Parkinson Disease Program, Neurology Division, Department of Medicine, Toronto Western Hospital, University Health Network, University of Toronto, Toronto ON, Canada. · Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, TorontoON, Canada; Division of Brain, Imaging and Behaviour - Systems Neuroscience, Krembil Research Institute, University Health Network, University of Toronto, TorontoON, Canada; Morton and Gloria Shulman Movement Disorder Unit & E. J. Safra Parkinson Disease Program, Neurology Division, Department of Medicine, Toronto Western Hospital, University Health Network, University of Toronto, TorontoON, Canada. ·Front Aging Neurosci · Pubmed #27891090.

ABSTRACT: The recent application of graph theory to brain networks promises to shed light on complex diseases such as Parkinson's disease (PD). This study aimed to investigate functional changes in sensorimotor and cognitive networks in Parkinsonian patients, with a focus on inter- and intra-connectivity organization in the disease-associated nodal and hub regions using the graph theoretical analyses. Resting-state functional MRI data of a total of 65 participants, including 23 healthy controls (HCs) and 42 patients, were investigated in 120 nodes for local efficiency, betweenness centrality, and degree. Hub regions were identified in the HC and patient groups. We found nodal and hub changes in patients compared with HCs, including the right pre-supplementary motor area (SMA), left anterior insula, bilateral mid-insula, bilateral dorsolateral prefrontal cortex (DLPFC), and right caudate nucleus. In general, nodal regions within the sensorimotor network (i.e., right pre-SMA and right mid-insula) displayed weakened connectivity, with the former node associated with more severe bradykinesia, and impaired integration with default mode network regions. The left mid-insula also lost its hub properties in patients. Within the executive networks, the left anterior insular cortex lost its hub properties in patients, while a new hub region was identified in the right caudate nucleus, paralleled by an increased level of inter- and intra-connectivity in the bilateral DLPFC possibly representing compensatory mechanisms. These findings highlight the diffuse changes in nodal organization and regional hub disruption accounting for the distributed abnormalities across brain networks and the clinical manifestations of PD.

24 Article Long-term double-blinded unilateral pedunculopontine area stimulation in Parkinson's disease. 2016

Mestre, Tiago A / Sidiropoulos, Christos / Hamani, Clement / Poon, Yu-Yan / Lozano, Andres M / Lang, Anthony E / Moro, Elena. ·Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Division of Neurology, Toronto Western Hospital, University of Toronto, University Health Network, Toronto, Ontario, Canada. tmestre@toh.on.ca. · Parkinson's disease and Movement Disorders Center, Division of Neurology, Department of Medicine, University of Ottawa Brain and Mind Institute, The Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (current affiliation). tmestre@toh.on.ca. · Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Division of Neurology, Toronto Western Hospital, University of Toronto, University Health Network, Toronto, Ontario, Canada. · Parkinson's Disease and Movement Disorders Program, Henry Ford Health System, West Bloomfield, Michigan, USA (current affiliation). · Department of Neurosurgery, Toronto Western Hospital, University of Toronto, University Health Network, Toronto, Ontario, Canada. · Service de Neurologie, Centre Hospitalier Universitaire de Grenoble, Université Joseph Fourier, Grenoble, France (current affiliation). ·Mov Disord · Pubmed #27392513.

ABSTRACT: BACKGROUND: Gait-related symptoms are often refractory to current available treatment options with a significant reduction in quality of life in Parkinson's disease. OBJECTIVES: The objective of this study was to determine the long-term efficacy and safety of unilateral pedunculopontine area stimulation for refractory gait and balance impairment in Parkinson's disease. METHODS: This study used periodic randomized double-blinded assessments until 4 years postoperatively. The primary outcomes were gait-related items of the UPDRS part II and the MDS-UPDRS part III. RESULTS: At baseline, the median age and disease duration was 63 years (interquartile range: 62, 65) and 15 years (interquartile range: 11, 20). At 2 years, patient-reported freezing (UPDRS part II, off-time) was significantly better when compared with baseline (P =.028), with 62.5% of responders. At 4 years, there was no significant change in the used outcomes, but 66.7 % (n = 4 of 6) were responders for off-time patient-reported freezing and falling. CONCLUSIONS: Pedunculopontine area stimulation has an initial but not sustained benefit for gait-related symptoms. © 2016 International Parkinson and Movement Disorder Society.

25 Article Deep Brain Stimulation: More Complex than the Inhibition of Cells and Excitation of Fibers. 2016

Florence, Gerson / Sameshima, Koichi / Fonoff, Erich T / Hamani, Clement. ·Division of Functional Neurosurgery, Department of Neurology, Hospital das Clínicas, School of Medicine of the University of São Paulo, São Paulo, SP, Brazil Department of Radiology and Oncology, School of Medicine of the University of São Paulo, São Paulo, SP, Brazil. · Department of Radiology and Oncology, School of Medicine of the University of São Paulo, São Paulo, SP, Brazil. · Division of Functional Neurosurgery, Department of Neurology, Hospital das Clínicas, School of Medicine of the University of São Paulo, São Paulo, SP, Brazil. · Division of Neurosurgery, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada Behavioural Neurobiology Laboratory and the Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Clement.Hamani@camh.ca. ·Neuroscientist · Pubmed #26150316.

ABSTRACT: High-frequency deep brain stimulation (DBS) is an effective treatment for some movement disorders. Though mechanisms underlying DBS are still unclear, commonly accepted theories include a "functional inhibition" of neuronal cell bodies and the excitation of axonal projections near the electrodes. It is becoming clear, however, that the paradoxical dissociation "local inhibition" and "distant excitation" is far more complex than initially thought. Despite an initial increase in neuronal activity following stimulation, cells are often unable to maintain normal ionic concentrations, particularly those of sodium and potassium. Based on currently available evidence, we proposed an alternative hypothesis. Increased extracellular concentrations of potassium during DBS may change the dynamics of both cells and axons, contributing not only to the intermittent excitation and inhibition of these elements but also to interrupt abnormal pathological activity. In this article, we review mechanisms through which high extracellular potassium may mediate some of the effects of DBS.

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