Parameters for subthalamic deep brain stimulation in patients with dystonia: a systematic review.
Deep brain stimulation (DBS) is used for treating dystonia, commonly targeting the subthalamic nucleus (STN). Optimal stimulation parameters are required to achieve satisfying results. However, recommended parameters for STN-DBS remain to be identified. In this review, we aimed to assess the optimal stimulation parameters by analyzing previously published STN-DBS data of patients with dystonia.We examined the STN-DBS stimulation parameters used in studies on dystonia selected on the PubMed/Medline database.Of the 86 publications retrieved from the PubMed/Medline database, we included 24, which consisted of data from 94 patients and 160 electrodes. Overall, the following average stimulation parameters were observed: amplitude, 2.59 ± 0.67 V; pulse width, 83.87 ± 34.70 μs; frequency, 142.08 ± 37.81 Hz. The average improvement rate was 64.72 ± 24.74%. The improvement rate and stimulation parameters were linearly dependent. The average improvement rate increased by 3.58% at each 10-Hz increase in frequency. In focal and segmental dystonia, the improvement rate and stimulation parameters were linearly dependent. The improvement rate increased by 6.06% and decreased by 2.14% at each 10-Hz increase in frequency and pulse width, respectively. Seventeen publications (83 patients) mentioned stimulation-related adverse effects, including dyskinesia (17), depression (8), transient dysarthria (5), weight gain (4), transient dysphasia (3), transient paresthesia (2), and sustained hyperkinesia (2).The optimal stimulation parameter for STN-DBS varies across patients. Our findings may be useful for DBS programming based on the specific dystonia subtypes, especially for patients with focal and segmental dystonia.