Minimal Clinically Important Differences for Burke‐Fahn‐Marsden Dystonia Rating Scale and 36‐Item Short‐Form Health Survey

Pallidal and Thalamic Deep Brain Stimulation in the Treatment of Unilateral Dystonia: A Prospective Assessment

BACKGROUND

The complexities of unilateral dystonia have led to exploring simultaneous (dual) globus pallidus internus (GPi) and motor ventral thalamus (Vim/Vop) deep brain stimulation (DBS), yet detailed assessments are lacking.

OBJECTIVES

To assess the efficacy of GPi, Vim/Vop, and dual DBS in unilateral dystonia.

METHODS

Three patients with unilateral dystonia (two idiopathic, one acquired), implanted with two DBS electrodes targeting ipsilateral Vim/Vop and GPi, were included. Three stimulation modalities were assessed. First, one electrode was activated, then the other, and finally, both electrodes were activated simultaneously.

RESULTS

DBS yielded substantial symptomatic reductions in all three evaluated stimulation modalities. Patients exhibited varying responses regarding quality-of-life and depressive symptoms. Treatment satisfaction didn't align with clinical improvements, potentially affected by unrealistic expectations.

CONCLUSIONS

This study contributes critical insights into GPi, Vim/Vop and simultaneous stimulation for unilateral dystonia. The safety of the procedure underscores the promise of this approach.

Bridging the gap between statistical significance and clinical relevance: A systematic review of minimum clinically important difference (MCID) thresholds of scales reported in movement disorders research

Background

Minimum clinically important difference (MCID) is the smallest change in an outcome measure that is considered clinically meaningful. Using validated MCID thresholds for outcomes powers trials adequately to detect meaningful treatment effects, aids in their interpretation and guides development of new outcome measures.

Objectives

To provide a comprehensive summary of MCID thresholds of various symptom severity scales reported in movement disorder.

Methods

We conducted systematic review of the literature and included studies of one or more movement disorders, and reporting MCID scales.

Results

2763 reports were screened. Final review included 32 studies. Risk of bias (RoB) assessment showed most studies were of good quality. Most commonly evaluated scale was Unified Parkinson's Disease Rating Scale (UPDRS) (11 out of 32). Four studies assessing MDS-UPDRS had assessed its different sub-parts, reporting a change of 2.64,3.05,3.25 and 0.9 points to detect clinically meaningful improvement and 2.45,2.51,4.63 and 0.8 points to detect clinically meaningful worsening, for the Part I, II, III and IV, respectively. For Parts II + III, I + II + III and I + II + III + IV, MCID thresholds reported for clinically meaningful improvement were 5.73, 4.9, 6.7 and 7.1 points respectively; while those for clinically meaningful worsening were 4.7, 4.2, 5.2 and 6.3 points, respectively. MCID thresholds reported for other scales included Abnormal Involuntary Movement Scale (AIMS), Toronto Western Spasmodic Torticollis Rating Scale (TWSRS), and Burke-Fahn-Marsden Dystonia Scale (BFMD).

Conclusion

This review summarizes all the MCID thresholds currently reported in Movement disorders research and provides a comprehensive resource for future trials, highlighting the need for standardized and validated MCID scales in movement disorder research.

Online mindfulness-based stress reduction improves anxiety and depression status and quality of life in caregivers of patients with severe mental disorders

OBJECTIVES

To explore the effects of online mindfulness-based stress reduction (MBSR) on the anxiety and depression status, and quality of life in the caregivers of patients with severe mental disorders.

METHODS

Ninety-three caregivers for patients with schizophrenia or bipolar disorder, who were hospitalized in Yunnan Provincial Mental Hospital in March 2021, were enrolled and randomly divided into control group (n=47) and MBSR intervention group (n=46). Both groups received basic health education and rehabilitation skill training, while the intervention group received additional online MBSR for 8 weeks. The anxiety and depression status, and the quality of life of the caregivers were evaluated by Self-rating Anxiety Scale (SAS), Self-rating Depression Scale (SDS) and the 36-item Short Form Health Survey (SF-36) before and 8 weeks after intervention, respectively.

RESULTS

Thirteen caregivers dropped out of the study, and 80 subjects (40 in each group) were included in the final analysis. At the baseline, there were no significant differences in SAS, SDS and SF-36 scores between two groups (all P>0.05). Compared with the baseline, SAS and SDS scores in the intervention group significantly decreased after 8 weeks of intervention (both P<0.01) and were significantly lower than those in the control group (both P<0.01). There were no significant changes in the control group (all P>0.05). Except the physiological function dimension, the total score and the scores of each dimension of SF-36 in the intervention group were significantly increased after 8-week intervention (all P<0.05), and were significantly higher than those in the control group (all P<0.01). There were no significant changes in the control group before and after intervention (all P>0.05).

CONCLUSIONS

Online MBSR can reduce the anxiety and depression levels, improve the quality of life in the caregivers of patients with severe mental disorders.

Long-Term Outcome of Subthalamic Deep Brain Stimulation for Generalized Isolated Dystonia

OBJECTIVES

Few studies have focused on subthalamic nucleus deep brain stimulation for refractory isolated dystonia, and the long-term outcomes are unclear. In this study, we evaluated the efficacy of subthalamic stimulation for generalized isolated dystonia for more than five years and explored the factors predicting clinical outcomes.

MATERIALS AND METHODS

A total of 16 patients with generalized isolated dystonia underwent a two-phase procedure for stimulation system implantation. After implanting the leads, we performed a test stimulation and observed the stimulation response. The severity of dystonia was assessed using a blinded rating of the Burke-Fahn-Marsden Dystonia Rating Scale based on videos recorded at scheduled times.

RESULTS

The mean follow-up time was 7.4 ± 2.2 years (5-12.5 years). The severity of dystonia improved significantly one year after surgery. The movement score decreased from 49.3 (40.9) points at baseline to 26.5 (43.5) points (-44.6%) at six months, 12.0 (22.5) points (-66.8%) at one year, 11.25 (17.6) points (-72.7%) at three years, and 12.5 (21.0) points (-72.6%) at the last follow-up. The improvement in motor symptoms resulted in a corresponding improvement in activities of daily living. Greater long-term outcomes were correlated with early stimulation responses, lower baseline movement scores, and female sex. When analyzed comprehensively, only the baseline movement score had meaningful predictive value for the outcome.

CONCLUSIONS

Our results indicate that subthalamic stimulation is effective and durable in treating generalized isolated dystonia. The subthalamic nucleus may be an alternative target for the treatment of refractory dystonia. Patients with less severe motor symptoms may benefit more from this treatment.

Minimal clinically important difference of the Functional Living Index-Emesis in patients with gynecological malignant tumor: A post hoc analysis of a single-arm study

AIM

This study aimed to explore the impact of minimum clinically important difference (MCID) of the Functional Living Index-Emesis (FLIE) in patients with gynecologic malignancies.

METHOD

This post hoc analysis included patients with gynecological malignant tumors in the Department of Oncology of our hospital between October 2020 and October 2021.

RESULTS

A total of 149 patients (aged 50.05 ± 12.24 years) were included. Most of the patients were married (75.8%), lived in the city (60.4%), and had a history of motion sickness (75.8%). The degree of nausea (9.00 [0.00, 16.00] vs. 30.00 [16.00, 48.00], P < 0.001) and vomiting (9.00 [0.00, 16.00] vs. 30.00 [16.00, 48.00], P < 0.001) were significantly improved after treatment. Taking the options in the scale as the subjective anchor, the MCID of FLIE for nausea and vomiting were 28.5 and 29 in anchor-based analysis, respectively. In the distribution-based analysis, the MCID of FLIE for nausea and vomiting were 2.41, 6.04, and 9.66; and 2.31, 5.78, and 9.24 in effect size of 0.2, 0.5, and 0.8, respectively.

CONCLUSION

The MCID of FLIE for nausea and vomiting in patients with gynecological malignant tumors was 28.5 and 29 in the anchor-based analysis, with higher specificity, and 6.04 and 5.78 in the distribution-based analysis, with higher sensitivity. The development of the MCID scale might be used to interpret the clinical significance of chemotherapy-induced nausea and vomiting in patients with gynecological malignancies and help to calculate the sample size for future clinical trials.

Deep Brain Stimulation for Refractory Status Dystonicus in Children: Multicenter Case Series and Systematic Review

OBJECTIVE

We sought to better understand the workflow, outcomes, and complications of deep brain stimulation (DBS) for pediatric status dystonicus (SD). We present a systematic review, alongside a multicenter case series of pediatric patients with SD treated with DBS.

METHODS

We collected individual data regarding treatment, stimulation parameters, and dystonia severity for a multicenter case series (n = 8) and all previously published cases (n = 77). Data for case series were used to create probabilistic voxelwise maps of stimulated tissue associated with dystonia improvement.

RESULTS

In our institutional series, DBS was implanted a mean of 25 days after SD onset. Programming began a mean of 1.6 days after surgery. All 8 patients in our case series and 73 of 74 reported patients in the systematic review had resolution of their SD with DBS, most within 2 to 4 weeks of surgery. Mean follow-up for patients in the case series was 16 months. DBS target for all patients in the case series and 68 of 77 in our systematic review was the globus pallidus pars interna (GPi). In our case series, stimulation of the posterior-ventrolateral GPi was associated with improved dystonia. Mean dystonia improvement was 32% and 51% in our institutional series and systematic review, respectively. Mortality was 4% in the review, which is lower than reported for treatment with pharmacotherapy alone (10-12.5%).

INTERPRETATION

DBS is a feasible intervention with potential to reverse refractory pediatric SD and improve survival. More work is needed to increase awareness of DBS in this setting, so that it can be implemented in a timely manner. ANN NEUROL 2023.

The anchor design of anchor-based method to determine the minimal clinically important difference: a systematic review

BACKGROUND

Positive results for clinical outcomes should be not only statistically significant, but also clinically significant. The minimum clinically important difference (MCID) is used to define the minimum threshold of clinical significance. The anchor-based method is a classical method for ascertaining MCID. This study aimed to summarise the design of the anchors of the anchor-based method by reviewing the existing research and providing references and suggestions.

METHOD

This study was mainly based on literature research. We performed a systematic search using Web of Science, PubMed, CNKI, Wanfang, and VIP databases. Two reviewers independently screened titles and abstracts to identify relevant articles. Data were extracted from eligible articles using a predefined data collection form. Discrepancies were resolved by discussion and the involvement of a third reviewer.

RESULT

Three hundred and forty articles were retained for final analysis. For the design of anchors, Subjective anchors (99.12%) were the most common type of anchor used, mainly the Patient's rating of change or patient satisfaction (66.47%) and related scale health status evaluation items or scores (39.41%). Almost half of the studies (48.53%) did not assess the correlation test between the anchor and the research indicator or scale. The cut-off values and grouping were usually based on the choice of the anchor types. In addition, due to the large number of included studies, this study selected the most calculated SF-36 (28 articles) for an in-depth analysis. The results showed that the overall design of the anchor and the cut-off value were the same as above. The statistical methods used were mostly traditional (mean change, ROC). The MCID thresholds of these studies had a wide range (SF-36 PCS: 2-17.4, SF-36 MCS: 1.46-10.28), and different anchors or statistical methods lead to different results.

CONCLUSION

It is of great importance to select several types of anchors and to use more reliable statistical methods to calculate the MCID. It is suggested that the order of selection of anchors should be: objective anchors > anchors with established MCID in subjective anchors (specific scale > generic scale) > ranked anchors in subjective anchors. The selection of internal anchors should be avoided, and anchors should be evaluated by a correlation test.

Minimal Clinically Important Difference (MCID) in Patient-Reported Outcome Measures for Neurological Conditions: Review of Concept and Methods

The concept of the minimal clinically important difference (MCID) emerged from the recognition that statistical significance alone is not enough to determine the clinical relevance of treatment effects in clinical research. In many cases, statistically significant changes in outcomes may not be meaningful to patients or may not result in any tangible improvements in their health. This has led to a growing emphasis on the importance of measuring patient-reported outcome measures (PROMs) in clinical trials and other research studies, in order to capture the patient perspective on treatment effectiveness. MCID is defined as the smallest change in scores that is considered meaningful or important to patients. MCID is particularly important in fields such as neurology, where many of the outcomes of interest are subjective or based on patient-reported symptoms. This review discusses the challenges associated with interpreting outcomes of clinical trials based solely on statistical significance, highlighting the importance of considering clinical relevance and patient perception of change. There are two main approaches to estimating MCID: anchor-based and distribution-based. Anchor-based approaches compare change scores using an external anchor, while distribution-based approaches estimate MCID values based on statistical characteristics of scores within a sample. MCID is dynamic and context-specific, and there is no single 'gold standard' method for estimating it. A range of MCID thresholds should be defined using multiple methods for a disease under targeted intervention, rather than relying on a single absolute value. The use of MCID thresholds can be an important tool for researchers, neurophysicians and patients in evaluating the effectiveness of treatments and interventions, and in making informed decisions about care.

Study design challenges and strategies in clinical trials for rare diseases: Lessons learned from pantothenate kinase-associated neurodegeneration

Substantial challenges in study design and methodology exist during clinical trial development to examine treatment response in patients with a rare disease, especially those with predominant central nervous system involvement and heterogeneity in clinical manifestations and natural history. Here we discuss crucial decisions which may significantly impact success of the study, including patient selection and recruitment, identification and selection of endpoints, determination of the study duration, consideration of control groups including natural history controls, and selection of appropriate statistical analyses. We review strategies for the successful development of a clinical trial to evaluate treatment of a rare disease with a focus on inborn errors of metabolism (IEMs) that present with movement disorders. The strategies presented using pantothenate kinase-associated neurodegeneration (PKAN) as the rare disease example can be applied to other rare diseases, particularly IEMs with movement disorders (e.g., other neurodegeneration with brain iron accumulation disorders, lysosomal storage disorders). The significant challenges associated with designing a clinical trial in rare disease can sometimes be successfully met through strategic engagement with experts in the rare disease, seeking regulatory and biostatistical guidance, and early involvement of patients and families. In addition to these strategies, we discuss the urgent need for a paradigm shift within the regulatory processes to help accelerate medical product development and bring new innovations and advances to patients with rare neurodegenerative diseases who need them earlier in disease progression and prior to clinical manifestations.

Dystonia management across Europe within ERN-RND: current state and future challenges

BACKGROUND

Since the first European-wide evaluation of dystonia management in 2016, several efforts have been made to improve dystonia-care. One of these was the development of the Dystonia Disease Group as a part of the European Reference Network for Rare Neurological Diseases (ERN-RND) that implemented several initiatives based on the recommendations made in 2016.

AIM

To evaluate the current state of dystonia management across Europe.

METHODS

Twenty-four countries were surveyed via 62 dystonia-experts from 44 ERN-RND-related centers.

RESULTS

Dystonia-experts for adult patients were available in all surveyed countries. However, almost half of the countries evaluated accessibility as merely 'satisfactory'. Access to genetic and neurophysiological testing was challenging to varying degrees in over half of countries. Main oral medications and botulinum toxin were available in all countries. Deep brain stimulation (DBS) was easily accessible in one-third of the countries. Dystonia research was conducted in 20/24 countries. Trainings on dystonia for general practitioners (GPs) were available in 11/24 countries. However, lack of trainings for other professionals was almost general. For pediatric dystonia, experts and specific training were available in over half of the countries.

CONCLUSIONS

In this overview, we present the current state of dystonia management within ERN-RND. Management has slightly improved since 2016 in several fields, including diagnostics, availability of DBS, and research. The results highlight that future challenges in dystonia management are accessibility of experts, and diagnostic tools and treatments, education on adult and childhood dystonia, and optimization of referral pathways. These findings are important for improving dystonia care across Europe.

Potential clinical and economic benefits of remote deep brain stimulation programming

Deep brain stimulation (DBS) teleprogramming may help reducing travel-related and other financial burdens for patients and maintaining DBS care in special situations. To determine travel-related burdens of DBS patients and explore effects of COVID-19 on DBS care. Travel- and visit-related data of 319 patients were retrospectively analyzed for the first year, five years, and ten years after initiating DBS. Frequencies of in-person and telemedicine visits over the 18-month periods just before and after the outbreak of COVID-19 in Hungary were also compared. Average travel distance during an in-person visit was 415.2 ± 261.5 km, while average travel time was 342.1 ± 199.4 min. Travel costs for the first year, five years, and ten years were 151.8 ± 108.7, 461.4 ± 374.6, and 922.7 ± 749.1 Euros, respectively. Travel distance, age, and type and severity of disease could help identify patients who would particularly benefit from teleprogramming. We detected a significant decrease in the number of visits during COVID-19 pandemic (from 3.7 ± 2.1 to 2.4 ± 2.7; p < 0.001) which mainly resulted from the decreased frequency of in-person visits (3.6 ± 2.0 vs. 1.7 ± 1.8; p < 0.001). Our results support the introduction of DBS teleprogramming in Hungary which could save money and time for patients while maintaining a secure delivery of DBS.

The minimal clinically important change in the motor section of the Burke-Fahn-Marsden Dystonia Rating Scale for generalized dystonia: Results from deep brain stimulation

BACKGROUND

The minimal clinically important difference (MCID) describes the smallest change in an outcome that is considered clinically meaningful. The Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) is the most frequently rating scale assessing the efficacy of deep brain stimulation therapy (DBS) for dystonia. To expand our understanding, we evaluated the MCID thresholds for the BFMDRS motor subscale (MS) using physician-reported outcomes.

METHODS

We assessed the MCID thresholds for the BFMDRS using movement disorder specialist ratings of videotapes from patients with genetically determined dystonia (Tor1A and THAP1) who underwent bilateral globus pallidum internum (GPi) DBS. We calculated the effect size of the BFMDRS-MS change and determined the MCID thresholds using the Clinical Global Impression of Change (CGIC).

RESULTS

Twelve participants with a median age at DBS of 44.5 (range:27-68) had baseline and follow-up BFMDRS-MS with a median post-DBS follow-up of 5.5 years. Based on descriptive analysis, patients with good improvement after DBS according to the CGIC [8/12 (67%)] had a median BFMDRS-MS score reduction of 77% [Interquartile range (IQR):66.2;91.0) with an effect size of 0.39, and those with non-improvement [4/12 (33%)], had a median BFMDRS-MS score reduction of 62% (IQR:36.6;83.6).

CONCLUSIONS

Our MCID estimates can be utilized in clinical practice in judging clinical relevance. However, further larger, powered studies are needed to simultaneously determine and compare MCID using patient and physician-reported outcomes in segmental and generalized dystonia in genetic and non-genetic populations.

Pharmacological and neurosurgical interventions for individuals with cerebral palsy and dystonia: a systematic review update and meta-analysis

AIM

To update a systematic review of evidence published up to December 2015 for pharmacological/neurosurgical interventions among individuals with cerebral palsy (CP) and dystonia.

METHOD

Searches were updated (January 2016 to May 2020) for oral baclofen, trihexyphenidyl, benzodiazepines, clonidine, gabapentin, levodopa, botulinum neurotoxin (BoNT), intrathecal baclofen (ITB), and deep brain stimulation (DBS), and from database inception for medical cannabis. Eligible studies included at least five individuals with CP and dystonia and reported on dystonia, goal achievement, motor function, pain/comfort, ease of caregiving, quality of life (QoL), or adverse events. Evidence certainty was evaluated using GRADE.

RESULTS

Nineteen new studies met inclusion criteria (two trihexyphenidyl, one clonidine, two BoNT, nine ITB, six DBS), giving a total of 46 studies (four randomized, 42 non-randomized) comprising 915 participants when combined with those from the original systematic review. Very low certainty evidence supported improved dystonia (clonidine, ITB, DBS) and goal achievement (clonidine, BoNT, ITB, DBS). Low to very low certainty evidence supported improved motor function (DBS), pain/comfort (clonidine, BoNT, ITB, DBS), ease of caregiving (clonidine, BoNT, ITB), and QoL (ITB, DBS). Trihexyphenidyl, clonidine, BoNT, ITB, and DBS may increase adverse events. No studies were identified for benzodiazepines, gabapentin, oral baclofen, and medical cannabis.

INTERPRETATION

Evidence evaluating the use of pharmacological and neurosurgical management options for individuals with CP and dystonia is limited to between low and very low certainty. What this paper adds Meta-analysis suggests that intrathecal baclofen (ITB) and deep brain stimulation (DBS) may improve dystonia and pain. Meta-analysis suggests that DBS may improve motor function. Clonidine, botulinum neurotoxin, ITB, and DBS may improve achievement of individualized goals. ITB and DBS may improve quality of life. No direct evidence is available for oral baclofen, benzodiazepines, gabapentin, or medical cannabis.