Surgery For Movement Disorders Research Articles

Critical evaluation of effectiveness of magnetic resonance imaging for targeting of deep brain areas in movement disorders surgery

Critical evaluation of effectiveness of magnetic resonance imaging for targeting of deep brain areas in movement disorders surgery

Challenges and scope of movement disorder surgery in Nepal

Challenges and scope of movement disorder surgery in Nepal

Advancements in the Clinical Outcomes of Functional Neurosurgery With Deep Brain Stimulation for Movement Disorders: A Literature Review.

This literature review explores recent advancements in deep brain stimulation (DBS) surgery for movement disorders. It highlights notable improvements, including closed-loop stimulation techniques, optogenetics, and improved surgical targeting. Positive clinical outcomes with low complication rates and improved motor symptoms are consistently reported. The review emphasizes the importance of minimizing risks through meticulous surgical practices and discussespotentialcomplications associated with DBS surgery. Future prospects focus on enhancing technology, refining surgical techniques, and conducting further research. Closed-loop stimulation optimizes DBS efficacy by tailoring stimulation parameters to individual patient needs. Optogenetics offers precise modulation of neural activity with light-sensitive proteins, enabling more targeted treatments. Cybersecurity measures are essential due to the integration of wireless and digital technologies in DBS systems. DBS surgery has significantly improved the management of movement disorders with its safety and effectiveness. Ongoing research in closed-loop stimulation, optogenetics, and cybersecurity is expected to further enhance DBS technology and outcomes, benefiting patients with treatment-resistant movement disorders.

Are Transventricular Approaches Associated With Increased Hemorrhage? A Comparative Study in a Series of 624 Deep Brain Stimulation Surgeries.

Deep brain stimulation (DBS) surgery has advanced tremendously, for both clinical applications and technology. Although DBS surgery is an overall safe procedure, rare side effects, in particular, hemorrhage, may result in devastating consequences. Although there are certain advantages with transventricular trajectories, it has been reasoned that avoidance of such trajectories would likely reduce hemorrhage. To investigate the possible impact of a transventricular trajectory as compared with a transcerebral approach on the occurrence of symptomatic and asymptomatic hemorrhage after DBS electrode placement. Retrospective evaluation of 624 DBS surgeries in 582 patients, who underwent DBS surgery for movement disorders, chronic pain, or psychiatric disorders. A stereotactic guiding cannula was routinely used for DBS electrode insertion. All patients had postoperative computed tomography scans within 24 hours after surgery. Transventricular transgression was identified in 404/624 DBS surgeries. The frequency of hemorrhage was slightly higher in transventricular than in transcerebral DBS surgeries (15/404, 3.7% vs 6/220, 2.7%). While 7/15 patients in the transventricular DBS surgery group had a hemorrhage located in the ventricle, 6 had an intracerebral hemorrhage along the electrode trajectory unrelated to transgression of the ventricle and 2 had a subdural hematoma. Among the 7 patients with a hemorrhage located in the ventricle, only one became symptomatic. Overall, a total of 7/404 patients in the transventricular DBS surgery group had a symptomatic hemorrhage, whereas the hemorrhage remained asymptomatic in all 6/220 patients in the transcerebral DBS surgery group. Transventricular approaches in DBS surgery can be performed safely, in general, when special precautions such as using a guiding cannula are routinely applied.

Chapter 7 - Neurophysiology during movement disorder surgery

During stereotactic procedures for treating medically refractory movement disorders, intraoperative neurophysiology shifts its focus from simply monitoring the effects of surgery to an integral part of the surgical procedure. The small size, poor visualization, and physiologic nature of these deep brain targets compel the surgeon to rely on some form of physiologic for confirmation of proper anatomic targeting. Even given the newer reliance on imaging and asleep deep brain stimulator electrode placement, it is still a physiologic target and thus some form of intraoperative physiology is necessary. This chapter reviews the neurophysiologic monitoring method of microelectrode recording that is commonly employed during these neurosurgical procedures today.

DBS and Ablation Surgery for Movement Disorders

DBS and Ablation Surgery for Movement Disorders

Radiofrequency Lesioning Surgery for Movement Disorders

Radiofrequency lesioning surgery is primarily performed to treat Parkinson's disease, dystonia, and tremor. Its effects are similar to those of deep brain stimulation (DBS). However, Radiofrequency lesioning surgery has not been popularized, possibly due to the over-evaluation of its risks. The current most available targets for the treatment of movement disorders include ventral intermediate (Vim) nucleus, ventral oral (Vo) nucleus, and globus pallidus internus (GPi). Vim thalamotomy is available for Parkinsonian tremor, essential tremor, dystonic tremor, and other various kinds of tremor, and it is highly effective. Bilateral vim thalamotomy is feasible when properly performed on tiny lesions on the bilateral vim nucleus. Vo thalamotomy is mainly available for focal hand dystonia. The safety profile of bilateral Vo thalamotomy has not yet been established, but it is thought that it may lead to irreversible hypophonia and dysarthria. Pallidotomy is selected for treatment of dystonia and Parkinson's disease. Although unilateral pallidotomy is a safe procedure, it can cause medically refractory parkinsonism including postural reflex disturbance and gait disorder. Delayed infarction on the posterior limb of internal capsule is another major concern associated with pallidotomy and can lead to hemiparesis. Correct understanding is absolutely essential to ensure the safety of radiofrequency lesioning surgery.

Innovative Applications of MR-Guided Focused Ultrasound for Neurological Disorders

Magnetic resonance-guided focused ultrasound (MRgFUS) is a cutting-edge technology that is changing the practice of movement disorders surgery. Given the noninvasive and innovative nature of this technology, there is great interest in expanding the use of MRgFUS to additional diseases and applications. Current approved applications target the motor thalamus to treat tremor, but clinical trials are exploring or plan to study noninvasive lesions with MRgFUS to ablate tumor cells in the brain as well as novel targets for movement disorders and brain regions associated with pain and epilepsy. Although there are additional potential indications for lesioning, the ability to improve function by destroying parts of the brain is still limited. However, MRgFUS can also be applied to a brain target after intravenous delivery of microbubbles to create cavitations and focally open the blood-brain barrier (BBB). This has already proven to be safe and technically feasible in human patients with Alzheimer's disease, and this action alone has potential to clear extracellular pathology associated with this and other neurodegenerative disorders. This also provides a foundation for noninvasive intravenous delivery of therapeutic molecules to precise brain targets after transient disruption of the BBB. Certain chemotherapies for brain tumors, immunotherapies, gene, and cell therapies are all examples of therapeutic or even restorative agents that normally will not enter the brain without direct infusion but which have been shown in preclinical studies to effectively traverse the BBB after transient disruption with MRgFUS. Here we will review these novel applications of MRgFUS to provide an overview of the extraordinary potential of this technology to expand future neurosurgical treatments of brain diseases.

Deep Brain Stimulation Surgery for Movement Disorders

Despite its discovery in the early 20th century and the decoding of its physiological circuitry later, these subcortical grey matter islands remain a mystery in functionality and pathophysiology. Deep brain lesioning & stimulation of precise programmed centres have elicited promising results in a very specific subgroup of patients. We delve into the basics of movement disorder surgery for the uninitiated in order to sensitise physicians and the general public themselves regarding the promises of these novel techniques as well as the immense potential of future discoveries in this neurological final frontier.

Analysis of the effects of subthalamic nucleus deep brain stimulation on somatosensation in Parkinson's disease patients.

Despite the subthalamic nucleus (STN) deep brain stimulation (DBS) is a treatment commonly used to ameliorate the motor symptoms of Parkinson's disease (PD), its effects on somatosensation is unclear. The purpose of this study was to investigate the potential effects of DBS on temperature, proprioceptive, tactile, exteroceptive, pain and cortical sensations, and odor identification in PD patients. The study included 14 patients (with a mean age of 59.78 ± 11.03 years; range, 44-70 years) with idiopathic PD who underwent DBS surgery for movement disorders caused by PD at the same Neurosurgery Department. All patients were tested while DBS was turned on (DBS-ON) and off (DBS-OFF). To clearly observe the effect of removing stimulation off, DBS devices were turned off by experimental clinical personnel for a minimum duration of 30 min prior to examination. Temperature, proprioceptive, tactile, exteroceptive, pain and cortical sensations, and odor identification were examined. We found that two-point discrimination was significantly lower during DBS-ON than DBS-OFF (p = 0.031). Tactile sensation and kinesthesia deviation degree were lower during DBS-ON than DBS-OFF, but were non-significant (p > 0.05). The number of correct answers on an assessment of graphesthesia was higher during DBS-ON, but was non-significant as well (p > 0.05). Odor identification was better during DBS-OFF. DBS may have an effective role to improve somatosensation and DBS-related benefits may not be explained by improvements in motor function alone, but rather by enhanced somatosensory processing. Further studies with larger study groups are needed.

Reoperation for device infection and erosion following deep brain stimulation implantable pulse generator placement.

Infection and erosion following implantable pulse generator (IPG) placement are associated with morbidity and cost for patients with deep brain stimulation (DBS) systems. Here, the authors provide a detailed characterization of infection and erosion events in a large cohort that underwent DBS surgery for movement disorders. The authors retrospectively reviewed consecutive IPG placements and replacements in patients who had undergone DBS surgery for movement disorders at the University of Alabama at Birmingham between 2013 and 2016. IPG procedures occurring before 2013 in these patients were also captured. Descriptive statistics, survival analyses, and logistic regression were performed using generalized linear mixed effects models to examine risk factors for the primary outcomes of interest: infection within 1 year or erosion within 2 years of IPG placement. In the study period, 384 patients underwent a total of 995 IPG procedures (46.4% were initial placements) and had a median follow-up of 2.9 years. Reoperation for infection occurred after 27 procedures (2.7%) in 21 patients (5.5%). No difference in the infection rate was observed for initial placement versus replacement (p = 0.838). Reoperation for erosion occurred after 16 procedures (1.6%) in 15 patients (3.9%). Median time to reoperation for infection and erosion was 51 days (IQR 24-129 days) and 149 days (IQR 112-285 days), respectively. Four patients with infection (19.0%) developed a second infection requiring a same-side reoperation, two of whom developed a third infection. Intraoperative vancomycin powder was used in 158 cases (15.9%) and did not decrease the infection risk (infected: 3.2% with vancomycin vs 2.6% without, p = 0.922, log-rank test). On logistic regression, a previous infection increased the risk for infection (OR 35.0, 95% CI 7.9-156.2, p < 0.0001) and a lower patient BMI was a risk factor for erosion (BMI ≤ 24 kg/m2: OR 3.1, 95% CI 1.1-8.6, p = 0.03). IPG-related infection and erosion following DBS surgery are uncommon but clinically significant events. Their respective timelines and risk factors suggest different etiologies and thus different potential corrective procedures.

Four-year follow-up results of magnetic resonance-guided focused ultrasound thalamotomy for essential tremor.

Following the emergence of magnetic resonance-guided focused ultrasound as a promising tool for movement disorder surgery, thalamotomy for essential tremor using this technique has become a useful tool based on its efficacy and lack of adverse effects. Here, we summarize the 4-year results of previous reports focusing on the durability of effectiveness of magnetic resonance-guided focused ultrasound thalamotomy for essential tremor. From October 2013 to August 2014, 15 patients with intractable essential tremor were enrolled. Twelve of them completed clinical assessment through 4 years of postoperative follow-up. Tremor severity, task performance, and disability were measured using the Clinical Rating Scale of Tremor. The mean age of the 12 patients was 61.7 ± 8.1 years. Maximally delivered energy was 15,552.4 ± 6574.1 joules. The mean number of sonications was 17.3 ± 1.6. The mean postoperative lesion volume was 82.6 ± 29.023 mm3 and in 1 year was a mean of 9.667 ± 8.573 mm3 . Four years postoperatively, improvement of the hand tremor score was 56%, that of the disability score was 63%, that of the postural score was 70%, and that of the action score was 63% compared with baseline; all improvements were significant and sustained over the 4-year period after thalamotomy. There was no permanent adverse effect throughout the 4-year follow-up period. Magnetic resonance-guided focused ultrasound thalamotomy exhibits sustained clinical efficacy 4 years after the treatment of intractable essential tremor. Adverse events are generally transient. A large cohort of patients who have undergone magnetic resonance-guided focused ultrasound thalamotomy with longer follow-up is needed to confirm our findings. © 2019 International Parkinson and Movement Disorder Society.

Leksell Radiosurgery for Movement Disorders.

Tremor is the most prevalent movement disorder in adults. Patients who are refractory to medical management can explore surgical intervention. Deep-brain stimulation (DBS) and radiofrequency thalamotomy (RFT) are surgical procedures for intractable tremor that target the ventralis intermedius (VIM) nucleus to relieve contralateral tremor. For patients who are not candidates for surgical procedures, stereotactic radiosurgery (SRS) is a minimally invasive management option for tremor relief. SRS has been used for the elderly, those considered high surgical risk for other surgical procedures, those who are unresponsive to either DBS or RFT, and those who prefer a less invasive option. Radiosurgical thalamotomy is performed using a central dose of 130-140 Gy delivered to the VIM nucleus of the thalamus. The critical aspect of the dose planning procedure is the selection of the target, which requires a neurosurgeon experienced with movement disorder surgery. More than 90% of patients experience improvements in their tremor and quality of life after radiosurgical thalamotomy. Adverse radiation effects rates are low (4%). In selected cases, staged bilateral procedure can also be performed to relieve bilateral refractory tremor. In patients with tremor-predominant Parkinson's disease, VIM thalamotomy is also effective.

Epilepsy surgery at its best: randomised prospective controlled trials in neurosurgery are no magic

Three fields of neurosurgery have truly lived up to the aspirations of evidence-based medicine with multiple randomised controlled trials published in top impact journals: epilepsy surgery and movement disorder surgery...

Deep Brain Stimulation for Parkinson Disease in the Philippines: Outcomes of the Philippine Movement Disorder Surgery Center

Deep brain stimulation (DBS) is an established treatment modality for Parkinson disease (PD). The first DBS for PD in the Philippines was performed at the Philippine Movement Disorder Surgery Center in 2006. There are no Philippine data on DBS for PD. We aim to determine the motor improvement and reduction in medication dosage of all patients with PD who underwent DBS at the Philippine Movement Disorder Surgery Center. This is a retrospective study of all patients with PD (n= 17) who underwent DBS from 2006 to 2016. The change in the Unified Parkinson's Disease Rating Scale (UPDRS) motor and levodopa equivalent dose were determined. There was a statistically significant reduction in the UPDRS motor in all patients off medication at 3 months (48.2%; P= 0.004), 1 year (47.3%; P= 0.026), 2 years (48.4%; P= 0.021), and 3 years (66.0%; P= 0.032) after DBS and on medication at 3 months (43.3%; P=0.023), 6 months (24.7%; P= 0.053), and 1 year (38.1%; P= 0.033). A significant reduction in the dosage of PD medications was also seen until the second year of follow-up (52.3%; P < 0.001). Adverse events included an attempted suicide and a device-related infection. DBS for PD improves the UPDRS motor score in the off-medication and on-medication state, with the maximal benefit seen at 3 years after surgery and reduces PD medication dosage by half. Although the benefit from DBS is undeniable, the high cost of the procedure precludes more patients from benefitting from it. There is a need for government support to expand access to DBS.

Optical Measurements during Deep Brain Stimulation Lead Implantation: Safety Aspects

Background: Intracerebral hemorrhage (ICH) is the most feared complication in deep brain stimulation (DBS) surgery. The aim of the study was to evaluate patient safety and outcome using laser Doppler flowmetry (LDF) as guidance tool during DBS implantations. Methods: An LDF probe adapted for the stereotactic system was used as guide for creation of the trajectory. The microcirculation along 83 preplanned trajectories was measured with the guide during DBS surgery for movement disorders. The microvascular blood flow levels were investigated for all measurement positions. Medical record and postoperative radiology were retrospectively reviewed. Results: Of 2,963 measurement positions, 234 (7.9%) showed at least a doubled blood flow compared to the surrounding tissue. Of these 2.2% had a more than 5 times higher blood flow in front of the probe tip. Along 1 trajectory, a small ICH was detected during surgery. Increased blood flow was more common close to sulci and verticals. Conclusion: Real-time LDF measurement of the microcirculation using a forward-looking probe during DBS surgery can detect blood flow peaks and further minimize the risk of developing ICH. No separate guide tube is necessary as the probe also creates the trajectory for the DBS lead.

Newer advances in lesional surgery for movement disorders.

An analysis of the existing literature on lesioning for movement disorders was undertaken to review lesion therapy and its advances. Advances in imaging technology and electrophysiological techniques used for localization of brain structures and its functions, such as microelectrode recordings and macrostimulation, have greatly improved the ability to accurately identify the target nuclei such as the ventrointermediate nucleus (Vim), globus pallidus interna (GPi) and subthalamic nucleus (STN). Many important changes are happening in the understanding of lesion making. Its application as a cheaper modality of treatment; being less cumbersome; having a wider geographical appeal; and more options to create a lesion, appeals to the clinician. The procedure is undergoing a revival.

The History of Movement Disorder Brain Surgery.

The first surgical procedures for abnormal movement disorders began in the 1930s, when surgeons first proposed ablative techniques of the caudate nucleus or transection of motor (pyramidal) pathways to reduce involuntary movements in patients with Parkinson's related tremor. During the 50-year interval between 1945 and 1995, the development of precise intracranial guiding devices, brain maps, and advanced imaging led to the refinement of appropriate deep brain targets affecting extrapyramidal pathways. Lesional surgery and subsequent neuroaugmentation using deep brain stimulation extended the role of deep brain surgery for a wider group of patients with tremor, rigidity, dyskinesia, and other involuntary movement disorders. Stereotactic radiosurgery has had wide application for tremor. The history of movement disorder surgery reads like a who's who of brilliant and resourceful surgeons who pushed the frontiers of neurosurgery. Even today, practitioners of functional brain surgery are among the most innovative practicing neurosurgeons.

Patient Evaluation and Selection for Movement Disorders Surgery: The Changing Spectrum of Indications.

This report summarizes the state-of-the-art and controversies around patient selection for deep brain stimulation (DBS) for various conditions. Parkinson's disease (PD): several class I studies have shown superiority of DBS over best medical treatment for advanced PD with fluctuations and further inclusion criteria. One class I study suggests that PD patients with early motor complications might gain more quality of life if operated within 3 years after the onset of fluctuations. The subthalamic nucleus (STN) is still the standard target. STN DBS has an impact on impulse control disorders though the exact mechanism is unclear. Tremor: essential tremor (ET) patients found to be eligible for DBS surgery should first be treated with primidone, propranolol, and with a combined therapy preoperatively. Second-line drugs (i.e., topiramate and gabapentin) may be useful. No class I studies exist for DBS treatment of ET. The optimal target of DBS in ET might be the posterior subthalamic area. Dystonia: there is class I evidence for primary generalized and segmental dystonia and for some botulinum-resistant focal dystonias. The impact of age, symptom duration, and DYT-mutation status in primary dystonia on the outcome of DBS surgery clearly demands more studies. DBS has a role in SCGE-mutation positive myoclonus dystonia and tardive dystonia. Finally, neurostimulation in secondary dystonia might be considered in selected patients based on an individual patient's approach.

Seventy Years with the Globus Pallidus: Pallidal Surgery for Movement Disorders Between 1947 and 2017.

The year 2017 marks the 70th anniversary of the birth of human stereotactic neurosurgery. The first procedure was a pallidotomy for Huntington's disease. However, it was for Parkinson's disease that pallidotomy was soon adopted worldwide. Pallidotomy was abandoned in the late 1950s in favor of thalamotomy because of the latter's more striking effect on tremor. The advent of levodopa put a halt to all surgery for PD. In the mid-1980s, Laitinen reintroduced the posteroventral pallidotomy of Leksell, and this procedure spread worldwide thanks to its efficacy on most parkinsonian symptoms including levodopa-induced dyskinesias and thanks to basic scientific work confirming the role of the globus pallidus internus in the pathophysiology of PD. With the advent of deep brain stimulation of the subthalamic nucleus, pallidotomy was again abandoned, and even DBS of the GPi has been overshadowed by STN DBS. The GPi reemerged in the late 1990s as a major stereotactic target for DBS in dystonia and, recently, in Tourette syndrome. Lately, lesioning of the GPI is being proposed to treat refractory status dystonicus or to treat DBS withdrawal syndrome in PD patients. Hence, the pallidum as a stereotactic target for either lesioning or DBS has been the phoenix of functional stereotactic neurosurgery, constantly abandoned and then rising again from its ashes. This review is a tribute to the pallidum on its 70th anniversary as a surgical target for movement disorders, analyzing its ebbs and flows and highlighting its merits, its versatility, and its resilience. © 2017 International Parkinson and Movement Disorder Society.