MS-II Saint Alphonsus Medical Group, Neurosurgery, Boise, ID, Idaho College of Osteopathic Medicine, Meridian ID Meridian, Idaho, United States
Introduction: Traditional "open-loop" deep brain stimulation (DBS) involves direct electrical stimulation of brain tissue and is administered without consideration of underlying patient physiology, as it lacks a means to detect and respond to cortical electrophysiology. Newer "closed-loop" systems have risen to prominence in recent years due to their ability to adapt and deliver stimulation when certain physiological states are met, thus being tailored to the patient's individual physiology. Additionally, we will discuss the extension of these closed-loop systems to spinal cord stimulators (SCS) This aim of this review is summarize the current clinical applications of closed-loop DBS as well as to offer a future outlook of what is to come.
Methods: The keywords "Deep Brain Stimulation" as well as "closed-loop DBS" were used for systematic searches within the databases of PubMed and Web of Science. With articles then being selected based on relevance to clinical applications of closed-loop DBS systems.
Results: 36 clinical trials were located involving closed-loop systems with Parkinson's Disease and other motor disorders (PD)(with adaptive DBS), Epilepsy (with Responsive DBS), and Chronic Pain (with SCS). In all three clinical conditions, closed-loop systems resulted in improved clinical outcomes with an improved motor scores (PD), decreased frequency of seizures (Epilepsy), and superior pain relief (Chronic Pain) vs. traditional open-loop systems. Notable new applications include the use of closed-loop systems in treatment-resistant depression as well as Tourette's Syndrome (TS). In TS, the closed-loop DBS system resulted in a comparable outcome to traditional DBS.
Conclusion : Current clinical evidence has shown significant support for closed-loop systems for the use in PD, Epilepsy, and chronic pain. However, significant research still needs to conducted into its potential applications for psychological disorders such as depression, anxiety, and PTSD. Additionally, new studies have pointed to closed-loop systems as potentially being used for neurorestorative interventions following spinal cord injury.
