Where are we with surgical therapies for Parkinson's disease?

Surgical therapies are now widely accepted in the treatment of medically refractory Parkinson's disease or levodopa-related side effects. Neuromodulation using deep brain stimulation (DBS) is currently the most well known surgical treatment, however other developing technologies are emerging. We briefly review active research areas in the field of DBS including timing of surgery, target selection and localization under general anesthesia and developments in closed loop stimulation systems. We then describe other evolving modalities such as lesioning using MR guided focused ultrasound and biological therapies.