A Scientometric Analysis of the 100 Most Cited Articles on Pallidotomy

<b><i>Background:</i></b> Pallidotomy is the oldest stereotactically performed neurosurgical procedure for movement disorders. Consequently, there is a wealth of literature available on the topic. <b><i>Objectives:</i></b> The aim of this analysis was to identify the top-cited articles on pallidotomy in order to discern the origins, spread, the current trends, and the future directions of this surgical procedure. <b><i>Methods:</i></b> We performed a search of the Web of Science database on 19 October 2020 using the keyword “pallidotomy.” The top-100 cited articles found were arranged in descending order on the basis of citation count (CC) and citation per year (CY). Relevant conclusions were derived. <b><i>Results:</i></b> The 100 top-cited articles were published between 1961 and 2017, in 24 journals. The average CC and CY were 118.1 (range – 856–46) and 5.326 (range – 29.52–2.09), respectively. The 3 most prolific authors were Lang AE (Neurologist – Toronto), Lozano AM (Neurosurgeon – Toronto), and Vitek JL (Neurologist – Atlanta). The Journal of Neurosurgery published the highest number of top-cited articles [Neurology. 1960;10:61–9]. The maximum articles were from the USA. University of Toronto and Emory University were the most productive institutions. <b><i>Conclusions:</i></b> Pallidotomy has gone through several ebbs and flows. Unilateral pallidotomy is currently recommended for the treatment of motor symptoms of Parkinson’s disease and dystonia. The need for further research and improved technology to make the technique safer and prove its efficacy is highlighted, especially keeping in mind a large number of populations to which the prohibitively expensive deep brain stimulation is unavailable.

PALLIDOTOMY IN PARKINSONIAN DISEASE: THE RENAISSANCE

ABSTRACT: BACKGROUND & OBJECTIVE: To assess the results of pallidotomy in Parkinson’s disease, and its effect on improving the lifestyle of the patients and cost-effectiveness. METHODOLOGY: A descriptive study was conducted at Neuro-Spinal & Cancer Care Institute, Karachi from June 2014 to January 2020. Patients who were known case of Parkinson’s disease refractory to medication and developed side effects to medication were included in the study and patients with previous brain surgery, associated brain disorders like Alzheimer’s disease, basal ganglia lesion, brain trauma were excluded. All patients were treated by pallidotomy on the contralateral side. The significance of the difference between groups to compare between the pre-op or post-op treatments was calculated through non-parametric assessment Kruskal-Wallis tests. RESULTS: The mean age of the patients was around 57 years. There were 34(81%) male and 8(19%) female patients’ Maximum number of patients who were more than 45 years, were having a left-sided proportion. More male patients were having a left-sided proportion as compared to female patients. The majority of patients (57.5%) were having dyskinesia as q primary symptom. A significant difference (p-value <0.001) existed in pre & post-operative UPDRS-III scores. A significant difference (p-value <0.001) also existed between on & off medications UPDRS- III (pre-op/post-op) scores. CONCLUSION: The result of pallidotomy is promising especially for unilateral pallidotomy to minimize the risk of cognition and speech disorder and long-term follow-up is needed to prove the statement further. Currently, pallidotomy is associated with minimal complications, more effective, and improving the quality of life of Parkinsonian patients.

Unilateral pallidotomy in the treatment of cervical dystonia: a retrospective observational study

OBJECTIVEThe objective of this study was to assess the efficacy of unilateral pallidotomy in patients with asymmetrical cervical dystonia.METHODSThis study retrospectively included 25 consecutive patients with asymmetrical cervical dystonia refractory to botulinum toxin injections, who underwent unilateral pallidotomy between January 2015 and April 2017. Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) scores were evaluated preoperatively and 1 week, 3 months, and 6 months postoperatively. The clinical responses were defined as good responders, exhibiting > 50% improvement in the TWSTRS score at 6 months postsurgery, or poor responders, exhibiting < 50% improvement in TWSTRS scores at 6 months postsurgery.RESULTSTwelve and 9 patients showed right- and left-side rotation, respectively; 1 and 3 patients had right- and left-side laterocollis, respectively. The mean age of onset and duration of the disease were 40.2 ± 13.9 and 8.9 ± 10.9 years, respectively. Mean TWSTRS scores were 38.4 ± 12.6 (p < 0.001), 17.3 ± 12.4 (p < 0.001), 19.5 ± 13.4 (p < 0.001), and 20.0 ± 14.7 (p < 0.001), preoperatively and 1 week, 3 months, and 6 months postoperatively, respectively. Fourteen patients (56%) demonstrated > 50% improvement in their TWSTRS total score (mean improvement of TWSTRS total score = 70.5%) 6 months postsurgically. Furthermore, preoperative TWSTRS severity score was a prognostic factor (odds ratio 1.37, 95% confidence interval 1.06–1.78, p = 0.003).CONCLUSIONSThese results suggest that unilateral pallidotomy is an acceptable treatment option for asymmetrical cervical dystonia. Further investigations with a larger number of cases and longer follow-up period are required to confirm these data.

Functional

This chapter discusses pain, movement disorders, epilepsy, dystonia, and neuropsychiatric disorder. The first set of studies examines the efficacy of spinal cord stimulation in managing pain in patients with chronic back pain and extremity pain, chronic pain, and neuropathic pain. The second set of studies evaluates the efficacy of deep brain stimulation of the subthalamic nucleus for the management of severe motor complications of Parkinson’s disease and compares it with ablative options such as unilateral pallidotomy. The third set of studies assesses the therapeutic value of nerve stimulation for patients with refractory epilepsy as well as its impact in seizure reduction. The next study explores the safety and efficacy of bilateral globus pallidus pars interna (GPi) stimulation for cervical dystonia, a complex condition that is often refractory to multiple medical and procedural therapies. Finally, the last study determines whether daily left prefrontal repetitive transcranial magnetic stimulation (rTMS) safely and effectively treats major depressive disorder.

Unilateral pallidotomy as a potential rescue therapy for cervical dystonia after unsatisfactory selective peripheral denervation

OBJECTIVESelective peripheral denervation (SPD) is a widely accepted surgery for medically refractory cervical dystonia (CD), but when SPD has failed, the available approaches are limited. The authors investigated the results from a cohort of CD patients treated with unilateral pallidotomy after unsatisfactory SPD.METHODSThe authors retrospectively analyzed patients with primary CD who underwent unilateral pallidotomy after SPD between April 2007 and August 2019. The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) was used to evaluate symptom severity before surgery, 7 days postsurgery, 3 months postsurgery, and at the last follow-up. TWSTRS subscores for disability and pain and the 24-item Craniocervical Dystonia Questionnaire (CDQ-24) were used to assess quality of life.RESULTSAt a mean final follow-up of 5 years, TWSTRS severity subscores and total scores were significantly improved (n = 12, mean improvement 57.3% and 62.3%, respectively, p = 0.0022 and p = 0.0022), and 8 of 12 patients (66.7%) were characterized as responders (improvement ≥ 25%). Patients with rotation symptoms before pallidotomy showed greater improvement in TWSTRS severity subscores than those who did not (p = 0.049). The most common adverse event was mild upper-limb weakness (n = 3). Patients’ quality of life was also improved.CONCLUSIONSUnilateral pallidotomy seems to offer an effective and safe option for patients with CD who have otherwise experienced limited benefits from SPD.

Pallidotomy after chronic deep brain stimulation

Recent publications have demonstrated that deep brain stimulation for Parkinson's disease still exerts beneficial effects on tremor, rigidity, and bradykinesia for up to 10 years after implantation of the stimulator. However with the progression of Parkinson's disease, features such as cognitive decline or “freezing” become prominent, and the presence of an implanted and functioning deep brain stimulator can impose a profound burden of care on the clinical team and family. The authors describe their experience in treating 4 patients who underwent removal of the implanted device due to either progressive dementia requiring full-time nursing or due to infection, and who subsequently underwent a unilateral pallidotomy.