Impact of Pallidothalamic Tractotomy on Motor and Non-Motor Symptoms in Dystonia Patients via Forel's Field H

Introduction: Pallidothalamic Tractotomy (PTT), targeting Forel's Field H, affects various neural pathways. Initially developed for refractory dystonia, PTT’s impact extends to non-motor symptoms, including psychiatric comorbidities, epilepsy, and autonomic regulation. This study examines PTT’s effects on dystonia severity, weight, psychiatric symptoms, and epilepsy control.

Methods: In a retrospective analysis of 69 dystonia patients, 10 received Focused Ultrasound (FUS) ablation and the remainder Radiofrequency (RF) ablation. Motor outcomes included changes in BFMDRS Total and neck scores, while non-motor outcomes, including weight, psychiatric symptoms (OCD, anxiety), and epilepsy control, were systematically evaluated.

Results: Dystonia symptoms improved significantly, with BFMDRS Total scores decreasing by 55.5% and neck scores by 52.7% post-surgery. Physiological effects included an average weight gain of 7.2 kg (pre-surgery mean: 58.0 kg; post-surgery mean: 65.2 kg), with left-sided PTT showing a 6.6 kg increase and right-sided 8.5 kg, peaking at 21.0 kg on the left. Psychiatric comorbidities also showed improvement, with one patient achieving an 85% reduction in OCD symptoms and another showing an 80% reduction in anxiety. Two patients with epilepsy achieved complete seizure control for one year.

Conclusion : PTT demonstrates substantial benefits for dystonia, with improvements in dystonia severity, psychiatric symptoms, and seizure control, supporting its potential as a comprehensive treatment. However, weight gain was observed, indicating a need for careful monitoring of autonomic effects. Further research is needed to clarify PTT’s therapeutic applications and associated risks.