Enrico Opri, PhD

Investigator:

Enrico Opri, PhD

Name of Institution:

Emory University, Atlanta, GA

Project Title:

DBS-induced local evoked potentials for asleep intraoperative functional mapping


Investigator Bio:

Dr. Enrico Opri is a postdoctoral fellow at Emory University School of Medicine, in the Miocinovic Lab. He received his PhD degree in Biomedical Engineering at the University of Florida, where he focused on closed-loop deep brain stimulation (DBS) for the improved treatment of patients affected by essential tremor and the mechanism of thalamocortical communication in motor behavior in humans. As a postdoctoral fellow, his research interest focuses on engineering-guided and objective electrophysiology-based methodologies for the improvement and enhancement of DBS programming and surgical implantation in Parkinson’s disease (PD).

Objective:

To investigate the use of deep brain stimulation (DBS) local evoked potentials for brain mapping during DBS implantation under anesthesia, including in interventional MRI (iMRI).

Background:

DBS has become a routine therapy for patients affected by PD, which requires the implantation of DBS leads within specific brain regions, to deliver brief electrical pulses to control the motor symptoms of PD. One of the most important factors to ensure the best therapeutic effect and minimize side effects of the stimulation, is the correct placement of the leads within the brain target region. Currently, one of the preferred techniques to find the DBS target region is by using microelectrode recordings (MER) of neural activity during the surgery, a process also known as functional mapping and evaluated by an expert clinician. This surgical modality requires the patient to be awake, and participate actively during the surgery, which may lead to anxiety and discomfort. However, if the patient would require moderate or generalized anesthesia, the feasibility of the functional mapping may be limited. An alternative surgical approach that addresses some of these challenges is intraoperative magnetic resonance imaging (iMRI), where implantation is based on real-time imaging of both the brain and the lead location. However, iMRI implantations may be hampered by poorly-defined target borders. As a result, there is a need for physiologic mapping in “asleep” surgeries. Recent studies, including work from our group, have proposed a novel neurophysiological signal, named DBS local evoked potentials (DLEP), which appears to be elicited by the electrical stimulation within the DBS target region. In addition, recent preliminary data from our group have shown that DLEP can be elicited under moderate anesthesia, require no patient interaction, are potentially easier to detect compared to other electrophysiological markers used currently in surgical functional mapping, and can be recorded directly from the implanted DBS leads.

Methods/Design:

We will evaluate DLEPs during standard DBS surgeries – both in the awake phase and the asleep phase (using propofol as the anesthetic agent).  We will also record DLEPs from iMRI cases under general anesthesia. These evaluations will seek to assess the feasibility and accuracy of the DLEP-based localization in estimating and validating the optimal DBS target location, comparing it with the imaging-only based approach and the microelectrode recording approach. Furthermore, we will test the predictive power of the intraoperative DLEP-based localization in informing which DBS contacts provide the patient with the best motor therapeutic benefit post-operatively.

Relevance to Diagnosis/Treatment of Parkinson’s Disease:

This success of this study will enable the integration of the benefit of brain mapping (based on DLEP), with the benefits of asleep surgery leading to better DBS surgical targeting and implantation.