Posteroventral Pallidotomy Research Articles

Simultaneous radiofrequency VIM thalamotomy and Posteroventral pallidotomy for management of dystonic tremors

Simultaneous radiofrequency VIM thalamotomy and Posteroventral pallidotomy for management of dystonic tremors

Rescue procedure for isolated dystonia after the secondary failure of globus pallidus internus deep brain stimulation.

Globus pallidus internus (GPi) deep brain stimulation (DBS) is widely used in patients with dystonia. However, 10-20% of patients receive insufficient benefits. The objectives of this study are to evaluate the effectiveness of bilateral subthalamic nucleus (STN) DBS along with unilateral posteroventral pallidotomy (PVP) in patients with dystonia who experienced unsatisfactory GPi-DBS and to address the reported rescue procedures after suboptimal DBS or lesion surgery in dystonia patients. Six patients with isolated dystonia who had previously undergone bilateral GPi-DBS with suboptimal improvement were included. Standardized assessments of dystonia using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) and quality of life using SF-36 were evaluated before surgery and 1, 6 months, and last follow-up (LFU) after surgery. STN bilateral OFF (bi-OFF), unilateral ON (uni-ON), and bilateral ON (bi-ON) states were recorded at LFU. Specific items were used to find publications published before 10 April 2022 regarding rescue procedures after suboptimal DBS or lesion surgery in patients with dystonia for reference. Eleven original studies including case reports/series were identified for discussion. Substantial clinical benefits were achieved in all six patients. Significant amelioration was achieved during the 1-month (6.5 ± 7.45; p = 0.0049), 6-month (5.67 ± 6.3; p = 0.0056) follow-ups, and at LFU (4.67 ± 4.72; p = 0.0094) when compared with the baseline (LFU of GPi DBS with on status) (17.33 ± 11.79) assessed by BFMDRS. The percentage of improvement reached 70.6, 74.67, and 77.05%, respectively. At LFU, significant differences were found between the stimulation bi-OFF and uni-ON (11.08 ± 8.38 vs. 9 ± 8.52, p = 0.0191), and between the stimulation bi-OFF and bi-ON (11.08 ± 8.38 vs. 4.67 ± 4.72, p = 0.0164). Trends depicting a better improvement in stimulation bi-ON compared with uni-ON (4.67 ± 4.72 vs. 9 ± 8.52, p = 0.0538) were observed. Our results suggest that bilateral STN-DBS plus unilateral PVP may be an effective rescue procedure for patients with isolated dystonia who experienced suboptimal movement improvement following GPi-DBS. However, given the heterogeneity of patients and the small sample size, these findings should be interpreted with caution.

The Role of Focused Ultrasound in the Management of Movement Disorders: Insights after 5 Years of Experience.

The Role of Focused Ultrasound in the Management of Movement Disorders: Insights after 5 Years of Experience.

Combined Unilateral Posteroventral Pallidotomy and Ventral Intermediate Nucleus Thalamotomy in Tremor-Dominant Parkinson's Disease versus Posteroventral Pallidotomy Alone: A Prospective Comparative Study

Background: The optimum target in surgery for Parkinson’s disease (PD) is still controversial, especially in patients with tremor-dominant PD. We aim to compare results in tremor-dominant patients undergoing pallidotomy vs. those undergoing simultaneous posteroventral pallidotomy (PVP) and ventral intermediate nucleus (VIM) thalamotomy. Methods: Twenty-four patients with tremor-dominant PD were included in this study. Twelve patients received unilateral PVP contralateral to the most affected side. The other 12 patients received simultaneous unilateral PVP and VIM thalamotomy contralateral to the most affected side. Assessment of results in both groups was achieved using both UPDRS “off” motor scores and UPDRS rest tremor subscores. Results: The mean UPDRS off motor score improved in the pallidotomy group from 61.3 preoperatively to 36.8 at 12 months. In the combined group, it improved from 59.6 to 35.2 at 12 months, with no statistically significant difference between both groups. On the other hand, while the mean tremor subscore in the pallidotomy group improved from a mean of 2.3–0.8, the tremors were abolished in all of the patients in the combined group except for 1 patient who showed slight infrequent tremors at 12 months. Conclusion: Patients with tremor-dominant PD achieve more improvement in tremor control after combined PVP and VIM thalamotomy.

History of neurosurgery for Parkinson's disease

Introduction The year 2017 marks the bicentenary of the publication of “An Essay on the Shaking Palsy” by surgeon James Parkinson and has prompted this summary of surgical treatments for Parkinson's disease (PD) over the last century. Material and Methods A survey of the medical literature through the 20th century up to 2017 was conducted. Results The French doctor Rene Leriche pioneered the first neurosurgical procedure to treat PD; he performed a surgical section of the cervical nerve roots . This was followed by various attempts at cervical spinal cord tractotomy, but the results were inconsistent. Intracranial procedures started with dentatectomy, but then the field shifted towards interruption of the pyramidal tract at various levels. Russell Meyers, then Gerard Guiot and F. Fenelon, were the first to target the basal ganglia , especially the pallidum and ansa lenticularis , with better results, but with high morbidity. In 1947, the advent of the stereotactic technique enabled safe, precise and efficient targeting of various areas of the pallidothalamic circuitry for surgical sections mainly for tremor. However, in 1970, L-dopa put a damper on all parkinsonian surgery. The renaissance of PD-related surgery started in the mid-1980s with the reintroduction of posteroventral pallidotomy by Lauri Laitinen in Sweden, which was soon followed by the introduction of deep brain stimulation (DBS) by Alim Louis Benabid in Grenoble and the rest is history. Conclusion Surgery to treat PD has gone through several phases and used many techniques, yet remains a valid alternative despite advances in PD medical treatment. Also, by an historical coincidence, it was a Frenchman who started surgery for PD, and a Frenchman who later devised the most recent and globally used technique of DBS.

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.

Unilateral posteroventral pallidotomy in the treatment of drug-induced dyskinesia in Parkinson's disease

to determine the efficacy of unilateral posteroventral pallidotomy (PVP) in the treatment of drug-induced dyskinesia (DID) in Parkinson's disease (PD). We analyzed surgical treatment of 14 patients with PD complicated by DID who underwent unilateral PVP at the Research Center of Neurology in the period between 2012 and 2015. The clinical type of DID was mainly represented by peak-dose choreoathetoid dyskinesia, more pronounced in the distal limbs, and predominantly unilateral. The severity of drug-induced dyskinesia was assessed on the UPDRS scale (part IV-A) before surgery and at 1 week and 6 months after surgery. One week after pallidotomy, all of the 14 patients had a regression of contralateral dyskinesia by 68.3±9.7%; 50% of patients had a regression of ipsilateral dyskinesias by 43%, on average. In 50% of cases, the dose of levodopa was reduced by 15%, on average. On examination at 6 months after surgery, regression of contralateral dyskinesia was 55.7±8.8%, and the severity of ipsilateral DID returned to the preoperative level. The use of pallidotomy significantly improved the indicators of daily activity and quality of life of patients. There were no significant postoperative complications. Three patients had mild speech disorders in the form of dysarthria, which regressed 2-3 weeks after surgery.

Current applications and limitations of surgical treatments for movement disorders.

Functional neurosurgery for the treatment of both psychiatric and neurological disorders has been performed regularly since the 1940s. However, misuse in the early days and the appearance of effective medical treatments, such as levodopa and neuroleptic drugs, greatly reduced surgical approaches over several decades. The development of a comprehensive model of basal ganglia pathophysiology in the 1990s facilitated the resurgence of functional neurosurgery, mainly for the treatment of levodopa-related motor complications in Parkinson's disease. This led first to the re-emergence of posteroventral pallidotomy and subsequently to deep brain stimulation. Thirty years on from this turning point, we find ourselves looking at a new scenario. Although deep brain stimulation is accepted worldwide and technical advances continue to improve this therapy, new questions and challenges such as long-term benefits and optimal targeting have emerged. In addition, new nonincisional tools used to perform ablative treatments, such as high-intensity focused ultrasound and gamma-knife, are challenging classical reluctance to therapeutic lesioning, and it remains to be determined how these approaches will fit into the array of movement disorder treatments. This review discusses the current clinical state of the art of functional neurosurgery in the treatment of Parkinson's disease, tremor, and dystonia. © 2017 International Parkinson and Movement Disorder Society.

Bilateral Pallidotomy by Using Deep Brain Stimulation Electrode in Parkinson’s Disease

Deep brain stimulation (DBS) is a safe and effective treatment in alleviating motor symptoms and complications in advanced Parkinson’s disease (PD). However, in some patients, the DBS system may need to be removed due to recurrent hardware infection. Here we report a case of a patient who had frequent internal pulse generator (IPG) site infections and eventually underwent bilaterally pallidotomy using previously implanted globus pallidus interna (GPi) DBS electrodes. A 57-yearold woman with advanced PD and was implanted bilateral subthalamic nucleus (STN) DBS. 18 months after she suffered from new onset loss of postural reflexes and frequent falls that were directly related with STN stimulation. Therefore, the STN electrodes were swithched to GPiand one year after switching to GPi DBS, she developed severe infection and skin erosion over the DBS hardware. The hardware had to be removed due to recurrent infections and before explanting the electrodes, bilateral pallidotomy with radiofrequency was performed by using the existing DBS electrodes. Two years after the bilateral posteroventral pallidotomy, the patient had good and stable control of PD. To our knowledge, this is the first case report where existing DBS electrodes were used for bilateral pallidotomy by RF. This technique is safe and efficient, but further studies and large series are needed to confirm its long-term benefits.

Gamma knife pallidotomy for treatment of Parkinson's disease: long term results, clinical study

Background: Deep brain stimulation (DBS) is now the preferred surgical treatment for advanced Parkinson’s disease (PD). Some patients however are not suitable candidates for an open surgical procedure or may prefer a procedure that does not include the permanent implantation of hardware. For such patients, gamma knife pallidotomy (GKP) may be a suitable alternative. Objective: The goal of this report was to describe the safety and effectiveness of posteroventral pallidotomy (GKP) performed with the Leksell gamma knife (LGK) for the treatment of advanced PD. Methods: Forty patients underwent a total of 51 GKP procedures with LGK between August 1993 and June 2009. Twenty nine patients underwent a unilateral procedure whereas 11 underwent bilateral procedures. Results: There were statistically significant improvements in off-medication unified Parkinson’s disease rating scale (UPDRS) scores for total scores (18.4%), motor scores (18.2%), tremor(72.4%) rigidity (51.2%) and bradykinesia (23.4%) scores and also for on medication dyskinesia scores (70.0%.) Bilateral procedures produced an additional incremental improvement in symptoms. Two patients suffered permanent complications. Conclusions: GKP offers a safe and effective procedure for the treatment of advanced PD. Although probably not as effective as DBS, it is particularly applicable to patients who may not be candidates for DBS.

Long‐term effect of unilateral pallidotomy on levodopa‐induced dyskinesia

Unilateral pallidotomy has been effectively used to treat parkinsonism and reduce levodopa induced dyskinesia (LID). We sought to determine the long-term effects of pallidotomy on LID in 10 patients who had initial benefit from pallidotomy but went on to require DBS surgery for symptom progression. The Dyskinesia Rating Scale (DRS) was used to rate and quantify LID in a blinded fashion. Though sample size was small, there was a trend towards a reduction in LID lasting up to 12 years suggesting that posteroventral pallidotomy may provide sustained benefit in reducing LID.

Long-term suppression of tremor by deep brain stimulation of the ventral intermediate nucleus of the thalamus combined with pallidotomy in hemiparkinsonian patients

Deep brain stimulation (DBS) of the ventral intermediate nucleus of the thalamus (VIM) is a powerful surgical option in the treatment of tremor-predominant Parkinson’s disease. However, its therapeutic efficacy depends on the tremor distribution. DBS is highly efficient in relief of distal appendicular tremor but not other types of tremor. Also, it is generally thought that DBS of the VIM has no significant beneficial effects on other motor symptoms of Parkinson’s disease. We report two hemiparkinsonian patients, in whom unilateral VIM DBS combined with posteroventral pallidotomy produced long-lasting suppression of not only hand tremor, but also leg or jaw tremor and other motor symptoms.

Globus pallidus internus firing rate modification after motor-imagination in three Parkinson’s disease patients

Motor imagery is thought to involve the same processes of movement preparation as actual movement. Imagination of a simple repetitive movement significantly decreased the firing rate of extracellular micro recording at sensorimotor neurons of globus pallidus internus in three patients with Parkinson's disease, who underwent microelectrode-guided posteroventral pallidotomy. These findings suggest, in agreement with previous clinical and functional neuroimaging studies that the motor corticostriatal circuit could be engaged in mental simulation.

Deterministic Dynamics in Neuronal Discharge from Pallidotomy Targets

The non-linear dynamic specificity of the firing pattern discharged from neurons of the internal globus pallidus (GPi) was investigated by recording their spontaneous firing using a microelectrode during posteroventral pallidotomy in eight patients with Parkinson's disease. Raw data from the cells were processed to extract spiking events (discharges above a selected threshold) and the interspike interval was measured. Using the unstable periodic orbits extraction method, significant period-1, -2 and -3 orbits were identified in burst firing discharged from the GPi cells in all eight patients, suggesting that deterministic dynamics exist in the timing of the discharges. As well as providing a useful peri-operative technique for locating posteroventral pallidotomy targets in Parkinson's disease, this method also provides a promising basis for investigating characteristic neuronal discharges in other regions of the brain and for various other neurological disorders.

Depressed Mood and Memory Impairment Before and After Unilateral Posteroventral Pallidotomy in Parkinson's Disease

Depressed Mood and Memory Impairment Before and After Unilateral Posteroventral Pallidotomy in Parkinson's Disease

Depressed Mood and Memory Impairment Before and After Unilateral Posteroventral Pallidotomy in Parkinson’s Disease

This study evaluated poor mood state as a moderator of changes in verbal recall ability from before to after unilateral posteroventral pallidotomy in 54 individuals with advanced Parkinson's disease. Repeated-measures analysis of covariance (controlling for motor disease severity) indicated that left-posteroventral pallidotomy subjects with depressed mood performed more poorly on measures of verbal list learning and story recall compared to nondepressed subjects or right-posteroventral pallidotomy subjects with depressed mood both before and after surgery. The results suggest that depressed mood should be taken into account when interpreting memory test performance in Parkinson's disease surgical candidates both before and after surgery.

Five-year follow-up of unilateral posteroventral pallidotomy in Parkinson's disease

Background Neurocognitive outcome research of individuals with Parkinson's disease after unilateral pallidotomy is inconsistent. Although some studies reported few cognitive changes, other investigations have more consistently shown both transient and long-term cognitive decline postoperatively. Methods We report the long-term motor and neurocognitive outcome 5 years post surgery for 18 patients with Parkinson's disease (12 men and 6 woman; all right-handed) who underwent right or left unilateral posteroventral pallidotomy. Results Pallidotomy patients revealed long-term motor benefits from the surgery in their “off” state and control of dopa-induced dyskinesias in their “on” state, which is consistent with previous research. We found mild declines in oral and visuomotor information processing speed, verbal recognition memory, and mental status 5 years after surgery, which differs from previous literature regarding the long-term neurocognitive outcome after pallidotomy. Differences between the right and left pallidotomy patients for both motor and cognitive skills were not found. Conclusion Although deep brain stimulation is presently the treatment of choice, pallidotomy continues to be performed around the world. Consequently, although unilateral pallidotomy should be considered a treatment option for patients with Parkinson's disease who suffer from severe unilateral disabling motor symptoms or dyskinesias, the long-term neurocognitive outcome should also be considered in treatment decisions.

Kinematic evaluation of gestural and repetitive single joint movements of the arm after posteroventral pallidotomy, subthalamotomy or both procedures combined in two Parkinson’s disease patients: two case studies

Two patients with severe Parkinson's disease undergoing partial or complete ablative interruption of basal ganglia (BG) output are presented. One patient who underwent bilateral subthalamotomy, and a second who underwent unilateral posteroventral pallidotomy, followed 7 years later by a bilateral subthalamotomy because of contralateral disease progression, were studied. In addition to the usual clinical evaluation, changes in joint kinematics observed during unconstrained, skilled multi-joint movement and repetitive single joint (RSJ) movement of the wrist were studied. Clinical UPDRS items referred to hand movements contralateral to the procedure, and instrumental measurement of RSJ improved in both patients after either pallidotomy or subthalamotomy. When both BG outflow paths were interrupted as was the case in the second patient (bilateral subthalamotomy after the initial pallidotomy), no added clinical improvement was observed, RSJ even deteriorated slightly. Instrument-based studies for movement alteration detection after simultaneous ablation of the globus pallidus and the subthalamic nucleus of these two patients showed greater sensitivity than clinical evaluation alone. Complex gestural movement performance remained unaffected after partial (subthalamotomy or pallidotomy) or complete interruption of BG outflow (case 2), indicating BG compensatory capacity after total outflow interruption remained intact.

What Happened to Posteroventral Pallidotomy for Parkinson’s Disease and Dystonia?

Fifteen years after its resurrection, pallidotomy for Parkinson's disease (PD) and dystonia has once again been supplanted, this time by deep brain stimulation (DBS). Did this occur because pallidotomy was not effective or safe, or because DBS was found to be more effective and safer? This review focuses on the evidence-and its quality-supporting the effectiveness and safety of pallidotomy for PD and dystonia, and the comparative effectiveness and safety of DBS of the subthalamic nucleus (STN) and globus pallidus pars interna (GPi). Discussed first are the determinants of "level 1" recommendations, including the confounding effects on interpretation of randomized clinical trials (RCTs) that fail to control for patient bias (i.e., placebo effects). Although several RCTs have been performed comparing unilateral pallidotomy to medical therapy, GPi DBS, or STN DBS for PD, none controlled for patient bias. Comparison of these trials to estimate the placebo effect, and examination of retrospective case series, suggests that the true effectiveness of unilateral pallidotomy is 20% to 30% reduction of 'off' total motor UPDRS scores, which is similar to the effects of unilateral GPi DBS or STN DBS, but less than bilateral STN DBS. At experienced centers, safety of unilateral pallidotomy appears equivalent to unilateral DBS, but bilateral DBS is likely safer than bilateral pallidotomy. Whereas there have been no RCTs of pallidotomy for dystonia, two double-blind, sham-controlled RCTs of bilateral GPi DBS were performed. Nevertheless, limited uncontrolled series suggest that bilateral pallidotomy is similar to GPi DBS in effectiveness and safety for dystonia. Thus, pallidotomy was not rejected because of lack of effectiveness or safety, and it remains a viable alternative in situations where DBS is not available or not feasible.

Prospective randomized 1-year follow-up comparison of bilateral subthalamotomy versus bilateral subthalamic stimulation and the combination of both in Parkinson's disease patients: a pilot study

It has been suggested that potential risk of hemiballismus after subthalamotomy makes DBS preferable to ablation for IPD treatment; however, cost and the need for regular electrode control have also been observed as disadvantages to stimulation. The objective was to compare efficacy and safety of different surgical approaches to STN, in a prospective randomized pilot study. Sixteen consecutive IPD patients randomized to receive either: bilateral STN-DBS, bilateral subthalamotomy or unilateral subthalamotomy plus contralateral STN-DBS implantation, and followed for 12 months after surgery. One patient died and was excluded from the analysis. Total and motor UPDRS scores, as well as drug-induced dyskinesias improved significantly at 1 year follow-up, regardless of the procedure administered and without statistically significant differences between treatment modalities. Discrete changes were observed on ACE and MMSE scores. Psychiatric examination of patients subjected to bilateral stimulation and lesion, revealed slight increment in apathy and irritability scores, coinciding with significant deterioration of mentation, behaviour and mood as measured using the UPDRS. One patient presented persistent hemiballismus and required ulterior posteroventral pallidotomy. In this small group of patients, overall motor performance significantly improved after all three procedures, without major differences in outcome. Adverse events were, nevertheless, observed after both ablation and stimulation. The role of bilateral subthalamotomy in patients unable to receive a DBS electrode-implant merits further exploration in a larger series of patients with longer follow-up.