SUNDYS: A Multicenter, Randomized, Double-blind, Sham-controlled, Parallel-group Trial

Shanghai Jiao Tong University

Status: Unknown

Conditions: Dystonia

Treatments: Procedure: Deep brain stimulation

Study type: Interventional

Funder types: Other

Identifiers

NCT04650958

Ruijin_SUNDYS

Details and patient eligibility

About

Dystonia is a group of movement disorders characterized by twisting, repetitive movements, or abnormal postures caused by involuntary muscle contractions and is characterized by a young age of onset and a high disability rate. Early intervention can reduce disability incidence, improve the patient's quality of life, and reduce the burden on families and society. Multiple international guidelines on dystonia have found deep brain stimulation (DBS) to be a safe and effective treatment for refractory dystonia. The globus pallidal internus (GPi) is the mostly widely used target for dystonia. However, there are limitations on the GPi DBS treatment, including slow onset of beneficial effects, poor improvement of axis symptoms, and potential stimulation-related side effects. Previous studies have described the highly successful use of subthalamic nucleus deep brain stimulation (STN DBS) in patients with refractory dystonia, suggesting that STN DBS is an effective and persisting alternative to pallidal deep brain stimulation. However, all STN DBS treated cases have been analyzed in open-label uncontrolled cohort studies, leading to limited data with a high level of evidence on the STN DBS in dystonia. Further, the investigators hypothesized STN has potentially more effectiveness when compared with GPi, and may be more power-saving and quick-acting. In this study, the investigators will organize a prospective randomized, double-blind, parallel-group, multicenter study comparing active versus sham stimulation in isolated segmental or generalized dystonia to evaluate the effectiveness and safety of STN DBS by measuring the impact on motor status, mental status, quality of life, the rate of response of the patients (the number of patients with ≥30% improvement in the movement score on the Burke-Fahn-Marsden Dystonia Rating Scale) and the rate of adverse events during the trial.

Enrollment: 38 estimated patients

Sex: All

Ages: 14+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Patients must meet criteria for the diagnosis of isolated generalized or segmental dystonia, including idiopathic and inherited dystonia, as defined by the Phenomenology and Classification of Dystonia: A Consensus Update 2013;

2. Patients will be ≥ 14 years old;

3. The course of disease will be ≥ 3 years;

4. Patients will have:

   1. Significant dystonia symptoms;
   2. Compromised life quality;
   3. Unsatisfactory response to oral treatment with anticholinergic agents antiepileptic agents, anti-dopamine agents, dopaminergic agents, or muscle relaxants;
   4. Unsatisfactory response to or contraindication for previous botulinum toxin treatment; and
   5. Ability to provide written informed consent.

Exclusion criteria

1. Patients with a diagnosis or probable diagnosis of acquired, compound, and complex dystonia, as defined by the Phenomenology and Classification of Dystonia: A Consensus Update 2013;
2. Previous brain surgery for dystonia;
3. Patients with cognitive impairment (MMSE score <24) or moderate-severe depressive disorder (BDI>25);
4. Patients with marked brain atrophy identified by magnetic resonance imaging (MRI) or computed tomography (CT);
5. Patients with other medical or psychiatric comorbidities that could increase the surgical risk or interfere with completion of the trial;
6. Patients with increased bleeding risk, or other factors contraindicating neurosurgery or general anesthesia;
7. Patients unable to cooperate with the assessments during the follow-up.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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38 participants in 2 patient groups

STN DBS stimulation group

Active Comparator group

Description:

In the STN DBS stimulation group, patients will receive a continuous DBS stimulation for 3 months and the first default parameters applied will be monopolar setting (0.5 V under threshold that causes side effects, 135 Hz, 90 µs, at one of the two dorsal contacts). If the default parameters are found not suitable for an individual patient due to unexpected reasons, an alternative method will be applied (e.g., decreased voltage) to try to maintain full compliance with the scheduled study.

Treatment:

Procedure: Deep brain stimulation

Sham stimulation group

Sham Comparator group

Description:

In the sham stimulation group, the programming will also start within 1 week after the surgery, but at each follow-up the DBS system will be turned off after the parameter is adjusted to the threshold that causes side effects without continuous stimulation. After the 3-month double-blind period the patients can choose to set on the DBS system again and receive regular continuous stimulation treatment.

Treatment:

Procedure: Deep brain stimulation