Maria Fiorella Contarino

Background: Cervical dystonia (CD) motor severity is typically quantified with the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). An expanded version of the Motor Severity section of the TWSTRS (“TWSTRS‐Delphi”) has been previously evaluated for its clinimetric properties but not for inter‐ and intrarater reliability. Objective: In this study we quantified inter‐ and intrarater reliability of the Motor Severity section of the TWSTRS‐Delphi for CD. Methods: Ten raters familiar with the TWSTRS‐Delphi and ten raters unfamiliar with it independently scored standardized videos from 90 patients with CD. We computed one‐way random intraclass correlation coefficient (ICC, absolute agreement) for total and item scores. We repeated assessments and calculations with a subset of raters to assess intrarater reliability. Results: Interrater reliability for the Total score was good for Familiar raters (ICC = 0.697) and fair for Unfamiliar raters (ICC = 0.566). Most individual items achieved fair–excellent interrater agreement in both groups (Familiar 0.415–0.763; Unfamiliar 0.416–0.769). Sagittal Shift, Duration, and Sensory Tricks showed poor agreement. Intrarater reliability was fair–excellent for most items in both groups (Familiar 0.494–0.927; Unfamiliar 0.413–0.877), but poor for Sagittal Shift and Duration among Familiar raters. Conclusions: The TWSTRS‐Delphi yields reproducible Total and item scores across movement disorder raters. The data pinpoint Sagittal Shift, Duration, and Sensory Tricks as the principal sources of between‐rater variability, defining immediate priorities for scale modification and focused training.

Encephalitis and cerebral abscesses are rare, serious complications of deep brain stimulation (DBS) surgery. We report on two patients with Parkinson's disease (PD) who developed a critical condition with focal neurological symptoms and decreased consciousness, after an initially uncomplicated subthalamic nucleus DBS implantation. Because of the clinical and radiological suspicion of encephalitis and brain abscess, DBS was explanted and the abscess drained. After prolonged antibiotic treatment they gradually fully recovered, with persistently improved PD symptoms in patient 1. Concluding, patients with DBS-related encephalitis or brain abscesses in a critical condition can have a favourable prognosis with proper and timely treatment.

Parkinson’s disease patients may experience a different therapeutic effect after replacement of the Medtronic Activa® deep brain stimulation neurostimulator with the newer Percept™ model, which features multiple independent current sources and constant-current control. We analyzed patient-reported therapeutic effect changes after Activa®-to-Percept™ replacements (AP, n=52) across six Dutch DBS-centers, comparing appropriate (AP+, n=36) and inappropriate/no (AP−, n=16) use of the manufacturer’s replacement workflow . Previous Activa®-to-Activa® replacements (AA, n=69) were used as reference. Worsened therapeutic effect was reported in 75.0% of AP−, 44.4% of AP+, and 21.7% of AA replacements (preplacement workflow is not properly used or in complex electrode configurations. We advise to use the workflow, inform the patient and plan closer follow-up appointments.

Background: Coping behavior of Parkinson's disease (PD) patients undergoing subthalamic Deep Brain Stimulation (STN‐DBS) is poorly understood. Identifying patients with ineffective coping could help prepare them better for surgery. Objectives: To clarify coping of PD patients preoperatively and the relation with psychiatric symptoms, quality of life (QoL), and cognition. Methods: Scores of 158 STN‐DBS candidates were retrospectively reviewed, including the Utrecht coping list (UCL), Symptom Checklist (SCL90‐R), Beck Depression Inventory (BDI2NL), PD Questionnaire 39 Summary Index (PDQ39‐SI) and the neuropsychological assessment. One‐sample and independent‐samples t‐tests, and correlation coefficients were calculated. Results: We found significant positive correlations between emotion‐focused coping (palliative/passive reactions, avoidance, expression of emotions, reassuring thoughts and seeking social support) and anxiety, depressive symptoms, and general psychosomatic symptoms. Patients reporting more palliative and passive reactions reported lower QoL. Patients with executive function deficits/impairment reported less active problem‐focused coping (‐1.89, 95% CI ‐3.60; ‐0.17); those with deficits/impairments in memory and executive functions reported less problem‐focused coping (‐1.96, 95% CI ‐3.81; −0.10), palliative reactions (‐2.12, 95% CI ‐3.72; 0.51), seeking social support (‐2.68, 95% CI ‐4.07; ‐1.28) and reassuring thoughts (‐1.41, 95% CI ‐2.52; ‐0.30) compared to cognitively unimpaired patients. Conclusions: Our data affirm the association of specific coping strategies with depression, anxiety, general physical and mental symptoms, and QoL in STN‐DBS candidates. Patients with impaired cognition, especially poor executive functioning, used ineffective coping strategies more often. Characterizing coping is simple and helps identify patients who may benefit from additional support to reinforce effective strategies, possibly leading to a less burdensome pre‐surgical trajectory.

Background: Predicting outcome for individuals with dystonia undergoing treatment with deep brain stimulation (DBS) remains challenging. This is further complicated by a lack of uniform screening, follow-up, and heterogeneous outcome measures. This study aims to achieve consensus on a national level among experts in the field to develop an agreed set of outcome measures and introduce more uniformity in the process of preoperative screening and follow-up. Methods: A modified Delphi process was conducted among experts in the field of DBS for dystonia. The process consisted of an inventory round, followed by two rounds of Delphi questionnaires, closing with a digital consensus meeting. Experts rated the importance of items within several categories: ((non-)motor symptoms, selection criteria, follow-up, DBS-related aspects, involved care providers). A threshold of 70% was maintained as consensus criterium. Results: After the first two rounds, consensus was reached on 40/59 items (adult DBS), and 47/61 items (pediatric DBS). The remaining items were rephrased into 28 statements (13 adult DBS, 13 pediatric DBS, and 2 concerning both) and voted on during a final consensus meeting. There, 23/28 statements (11 adult, 11 pediatric, 1 both) reached consensus. Overall, after three rounds, on most items consensus was reached. Discussion: In this Delphi study, a high level of consensus among national experts was achieved on outcome measures and the process of screening and follow-up in DBS for dystonia for adults and children. The results present national consensus and offer an excellent start for collaborative international studies on best practice for DBS in dystonia.

Selecting optimal contacts for chronic deep-brain stimulation (DBS) requires a monopolar review, involving time-consuming manual testing by trained personnel, often causing patient discomfort. Neural biomarkers, such as local field potentials (LFP), could streamline this process. This study aimed to validate LFP recordings from chronically implanted neurostimulators for guiding clinical contact-level selection. We retrospectively analysed bipolar LFP recordings from Parkinson's disease patients across three centres (Netherlands: 68, Switzerland: 21, Germany: 32). Using beta-band power measures (13-35 Hz), we ranked channels based on clinical contact-level choices and developed two prediction algorithms: (i) a "decision tree" method for in-clinic use and (ii) a "pattern based" method for offline validation. The "decision tree" method achieved accuracies of 86.5% (NL), 86.7% (CH), and 75.0% (DE) for predicting the top two contact-levels. Both methods outperformed an existing algorithm. These findings suggest LFP-based approaches can enhance DBS programming efficiency, potentially reducing patient burden and clinical workload.

Background: Finely-tuned gamma (FTG) activity—spontaneous narrowband oscillations within the low-gamma range or entrained to half the stimulation frequency—is traditionally associated with ON medication states and dyskinesia in Parkinson’s disease (PD), representing a potential biomarker for adaptive deep brain stimulation (DBS). However, the conditions in which FTG arises and its determinants remain unclear. Methods: Local field potentials recorded in the subthalamic nucleus (STN) in PD patients with SenSight ^TM leads and Percept ^TM neurostimulator were retrospectively analyzed. The analysis was guided by a comprehensive list of clinically relevant questions. Results: Among 67 patients (134 STN), spontaneous FTG was observed in 11% of STNs, and entrained FTG—including both 1:2 and the novel 1:1 entrainment— in 33%. FTG types never appeared simultaneously and were mostly ON-related but independent of dyskinesia. Beta-activity was inversely related with 1:2 entrainment during stimulation state transitions. Notably, as previously hypothesized, 1:2 entrainment diminished with higher stimulation amplitudes and was inversely related to 1:1 entrainment. Conclusions: This study provides clinical evidence of 1:1 entrainment. FTG expression – spontaneous, 1:2, or 1:1 entrained – is modulated by DBS and clinical state, but can occur independent of dyskinesia. We confirm that FTG is prokinetic and is inversely related with akinetic beta activity.