Staged bilateral pallidotomy for dystonic camptocormia: case report

Bilateral pallidotomy for acquired or heredodegenerative generalized dystonia in children

OBJECTIVE

Dystonias are relatively rare disorders characterized by sustained or intermittent muscle contractions causing abnormal movements or postures. Generalized dystonia is a therapeutic challenge because medications are unable to control dystonia adequately in most patients. These patients may be candidates for surgical therapy. The commonly used surgical procedures in these patients are pallidotomy and deep brain stimulation. Limited studies are available on the role of pallidotomy in children with acquired/heredodegenerative generalized dystonia. The objective of this study was to describe the authors’ experience with bilateral pallidotomy in this group of patients.

METHODS

The authors retrospectively reviewed all pediatric patients (less than 18 years of age) with acquired/heredodegenerative generalized dystonia who underwent bilateral simultaneous pallidotomy at their center between January 2014 and January 2021. Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores before and after surgery were recorded. Complications arising after the procedure were recorded as well.

RESULTS

Ten patients (8 male and 2 female) with a mean (range) age of 11.1 (5–17) years were included in this study. The mean duration between disease onset and surgical intervention was 3.9 years. Two patients presented in status dystonicus. The mean ± SD (range) preoperative BFMDRS score of the patients without status dystonicus (n = 8) was 80 ± 18.9 (59.5–108). The mean ± SD BFMDRS score at the time of discharge from the hospital after surgery was 58.8 ± 37.9. Three patients had more than 20% change in BFMDRS score at the time of discharge from the hospital. The mean improvement was 25.5% at the end of 1 year. Of 5 surviving patients in the non–status dystonicus group, 3 patients had more than 40% change in BFMDRS score while the other 2 patients developed recurrence at the last follow-up (4.5 years). Status dystonicus abated after bilateral pallidotomy in both patients. Permanent bulbar complications were seen in 2 patients.

CONCLUSIONS

Bilateral pallidotomy may result in clinically significant improvement in children with acquired/heredodegenerative generalized dystonia, although the benefits should be closely weighed against the risk of irreversible bulbar dysfunction. It is a viable option for children in resource-limited settings.

Specific movement and disability improvements in Burke-Fahn-Marsden Dystonia Rating Scale derived from pallidotomy in refractory patients to medical treatment

BACKGROUND

Dystonia is a movement disorder associated with significant disability and is usually refractory to medical treatment. Pallidotomy may decrease dystonic movements. The aim of this study was to quantify movement and disability improvements through Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS).

METHODS

We carried out a longitudinal clinical study in patients with refractory primary and secondary dystonia, who underwent radiofrequency (RF) unilateral and bilateral lesions on the postero-ventro-lateral globus pallidus internus (GPi), evaluating the outcomes through BFMDRS and variables as age, time of evolution, etiology, body distribution, planned target coordinates, and lesion size, during a mean follow-up time of 35.67 months.

RESULTS

Nine RF pallidotomies were performed on 6 patients, 7 right-sided and 2 left-sided; three patients were treated unilaterally for one occasion, while the others underwent 2 surgeries, including one staged bilateral procedure. Mean BFMDRS scores for movement were 38.5 preoperative and 25.5 postoperative, and for disability were 20.4 preoperative and 17.3 postoperative. We noticed improvement in movement (32.54%, p = 0.001) and disability (17.23%, p = 0.002). There was one right GPi and internal capsule (IC) infarction with contralateral hemiparesis as sequelae.

CONCLUSIONS

RF pallidotomy is an effective and accessible procedure to reduce BFMDRS scores in refractory dystonia if patients are correctly selected by severity, evolution, and disability as determining factors.

Bilateral Pallidotomy for Dystonia: A Systematic Review

Stereotactic lesioning of the bilateral globus pallidus (GPi) was one of the first surgical treatments for medication‐refractory dystonia but has largely been abandoned in clinical practice after the introduction of deep brain stimulation (DBS). However, some patients with dystonia are not eligible for DBS. Therefore, we reviewed the efficacy, safety, and sustainability of bilateral pallidotomy by conducting a systematic review of individual patient data (IPD). Guidelines of the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses and IPD were followed. In May 2020, Medline, Embase, Web of Science, and Cochrane Library were searched for studies reporting on outcome of bilateral pallidotomy for dystonia. If available, IPD were collected. In this systematic review, 100 patients from 33 articles were evaluated. Adverse events were reported in 20 patients (20%), of which 8 were permanent (8%). Pre‐and postoperative Burke‐Fahn‐Marsden Dystonia Rating Movement Scale scores were available for 53 patients. A clinically relevant improvement (>20%) of this score was found in 42 of 53 patients (79%). Twenty‐five patients with status dystonicus (SD) were described. In all but 2 the SD resolved after bilateral pallidotomy. Seven patients experienced a relapse of SD. Median‐reported follow‐up was 12 months (n = 83; range: 2–180 months). Based on the current literature, bilateral pallidotomy is an effective and relatively safe procedure for certain types of dystonia, particularly in medication‐refractory SD. Although due to publication bias the underreporting of negative outcomes is very likely, bilateral pallidotomy is a reasonable alternative to DBS in selected dystonia patients. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.