The objective of this project is to evaluate next generation visualization tools and surgical targeting models for clinical deep brain stimulation (DBS).

This study will evaluate the performance of HoloDBS software in comparison to the current standard (SOC) clinical planning tools to prepare for DBS surgery. The investigators hypothesize that HoloDBS will provide more detailed and anatomically useful information to the neurosurgeon and neurologist than the current clinical standard.

The study team reviews electronic medical records (EMR) from patients who are undergoing DBS surgery. There are no study visits involved in this study as only data from standard clinical care will be used. All study activities are executed by the study team and there are no interventions.

Electronic medical records (EMR) from all patients undergoing preoperative DBS evaluation will be reviewed and their data will be used for this study's purposes if they fit the inclusion and exclusion criteria.

Inclusion criteria:

• age 18 years and over
• meeting qualification for deep brain stimulation for Parkinson's disease with one or more of medication refractory tremor, motor fluctuations despite medication optimization, or levodopa responsiveness but limited by medication induced adverse effects (nausea, dystonia, dyskinesia for example).

Exclusion criteria:

• consideration of alternate diagnosis to Parkinson disease
• high risk medical comorbidities which would make the patient not a candidate for surgery.

Patients with Parkinson's disease scheduled for Deep Brain Stimulation Surgery