Perspective of DBS for Parkinson’s Disease and Involuntary Movements

Abstract

  Deep brain stimulation (DBS) is an indispensable technique in the current treatment strategy for Parkinson’s disease (PD) and involuntary movements. Here, we discuss the future prospects of DBS for treating movement disorders, based on the results of studies conducted so far.

   [Parkinson’s disease] : It is currently difficult to decide whether the subthalamic nucleus (STN) or the globus pallidus internus (GPi) is better as the target for DBS treatment. The decision should be based on each patient’s symptoms. DBS is generally ineffective for levodopa-unresponsive motor symptoms, but the pedunculopontine nucleus (PPN) is expected to be a target that can improve levodopa-resistant axial symptoms. Its side effects may be reduced by directional (current) steering that can control current diffusion to neighboring structures in the brainstem. [Dystonia] : The effect of GPi-DBS has been established statistically, but the postoperative improvement varies across patients and studies. The patient characteristics that predict their treatment outcomes are discussed. [Essential tremor] : The thalamic ventrointermediate (Vim) nucleus is the major target for DBS and conventional radiofrequency thalamotomy. A new incisionless technique called “transcranial ultrasound surgery (FUS)” facilitates reevaluation of ablation surgery. However, because of possible side effects such as irreversible dysphagia or dysarthria, bilateral FUS is not recommended at present. [Rare involuntary movements] : DBS theoretically can be applied for rare involuntary movements including Lance-Adams syndrome, a metabolic neurodegenerative disease, ballismus, and Holmes’ tremor, but its use for these conditions has only been reported in relatively few case reports.

  In conclusion, adaptive optimization based on disease and patient properties is necessary while promoting development of DBS through introduction of new technology.