Deep Brain Stimulation of the Globus Pallidus Internus and Externus in Multiple System Atrophy.

BACKGROUND: Multiple system atrophy with parkinsonism (MSA-P) is a progressive condition with no effective treatment. OBJECTIVE: The aim of this study was to describe the safety and efficacy of deep brain stimulation (DBS) of globus pallidus pars interna and externa in a cohort of patients with MSA-P. METHODS: Six patients were included. Changes in Movement Disorders Society Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS III), Parkinson's Disease Questionnaire (PDQ-39) scores, and levodopa equivalent daily dose were compared before and after DBS. Electrode localization and volume tissue activation were calculated. RESULTS: DBS surgery did not result in any major adverse events or intraoperative complications. Overall, no differences in MDS-UPDRS III scores were demonstrated (55.2 ± 17.6 preoperatively compared with 67.3 ± 19.2 at 1 year after surgery), although transient improvement in mobility and dyskinesia was reported in some subjects. CONCLUSIONS: Globus pallidus pars interna and externa DBS for patients with MSA-P did not result in major complications, although it did not provide significant clinical benefit as measured by MDS-UPDRS III. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Multicenter Validation of Individual Preoperative Motor Outcome Prediction for Deep Brain Stimulation in Parkinson's Disease.

BACKGROUND: Subthalamic nucleus deep brain stimulation (STN DBS) is an established therapy for Parkinson's disease (PD) patients suffering from motor response fluctuations despite optimal medical treatment, or severe dopaminergic side effects. Despite careful clinical selection and surgical procedures, some patients do not benefit from STN DBS. Preoperative prediction models are suggested to better predict individual motor response after STN DBS. We validate a preregistered model, DBS-PREDICT, in an external multicenter validation cohort. METHODS: DBS-PREDICT considered eleven, solely preoperative, clinical characteristics and applied a logistic regression to differentiate between weak and strong motor responders. Weak motor response was defined as no clinically relevant improvement on the Unified Parkinson's Disease Rating Scale (UPDRS) II, III, or IV, 1 year after surgery, defined as, respectively, 3, 5, and 3 points or more. Lower UPDRS III and IV scores and higher age at disease onset contributed most to weak response predictions. Individual predictions were compared with actual clinical outcomes. RESULTS: 322 PD patients treated with STN DBS from 6 different centers were included. DBS-PREDICT differentiated between weak and strong motor responders with an area under the receiver operator curve of 0.76 and an accuracy up to 77%. CONCLUSION: Proving generalizability and feasibility of preoperative STN DBS outcome prediction in an external multicenter cohort is an important step in creating clinical impact in DBS with data-driven tools. Future prospective studies are required to overcome several inherent practical and statistical limitations of including clinical decision support systems in DBS care.

Successful Unilateral Surgical Approach to Internal Globus Pallidus and Ventral Intermediate Nucleus of the Thalamus in 3 Cases of Myoclonus-Dystonia Syndrome.

Surgical approaches of internal globus pallidus (GPi) and ventral intermediate thalamic nucleus (Vim) have been used to treat different movement disorders. Three subjects with myoclonus-dystonia syndrome were surgically treated, one of them with GPi and Vim stimulation, while radiofrequency ablation of these structures was performed in the other 2 subjects. Surgical approach of both targets was performed simultaneously on each subject. Mean follow-up was of 33.3 months (22-48 months), the Unified Myoclonus Rating Scale action myoclonus (AM), functional tests (FT), patient questionnaire (PQ) sub-scores, and the Unified Dystonia Rating Scale (UDRS) were used during assessments. Improvement in all scales were seen 6 months after surgery (AM: 74%, FT: 60%, PQ: 63%, UDRS: 65%), and this benefit persisted throughout follow-up (AM: 61%, FT:62%, PQ: 65%, UDRS: 86%). No adverse events were noticed. Simultaneous unilateral procedures of GPi and Vim by either stimulation or ablation techniques improve both motor and functional scores in myoclonus-dystonia syndrome.

Blepharospasm as a Manifestation of Peak of Dose Dyskinesia in Parkinson Disease.

OBJECTIVES: The aim of the study was to report 4 patients with Parkinson disease (PD) and On-period blepharospasm (BS). METHODS: We analyzed patients with PD and motor fluctuations who developed BS in several different centers in Latin America. RESULTS: Four patients had BS while in the ON periods. CONCLUSIONS: Blepharospasm in the On period in patients with PD is extremely uncommon, and our series is the only one to describe such association.

A Multicenter Comparative Study of Impulse Control Disorder in Latin American Patients With Parkinson Disease.

OBJECTIVES: Impulse control disorder (ICD) is a common adverse effect in patients with Parkinson disease who receive dopamine agonists; however, other factors are involved in its manifestations. To study the frequency and factors involved in the development of this adverse effect in a Latin American population, we conducted a cross-sectional multicenter study. METHODS: Two hundred fifty-five patients in 3 Latin American centers were evaluated by examination and application of scales (Unified Parkinson's Disease Rating Scale, Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale, Hoehn and Yahr, Clinical Impression of Severity Index for Parkinson's Disease). RESULTS: Of the patients, 27.4% had ICD, most of whom were on dopamine agonists. Other associated risk factors included a younger age at onset of Parkinson disease, moderate symptoms, a shorter evolution of the clinical manifestations, rapid eye movement (REM) sleep disorder behavior, and the consumption of tea, mate, and alcohol. CONCLUSIONS: The frequency of ICD is higher in Latin America than in Anglo-Saxon populations. Consuming tea and mate, in addition to the use of dopamine agonists, is a factor that may demonstrate a genetic link that predisposes patients to the establishment of an ICD.