TUS to Disrupt Pathological Oscillations

Transcranial Ultrasound Stimulation (TUS): TUS will be applied using a commercially available transcranial ultrasound transducer and neuronavigation system that allows for targeting of specific brain regions. TUS targeting will be based on participant specific MRI and CT scans that take place as part of routine pre-operative planning before DBS implantation. TUS will then be applied during cognitive and motor tasks as described below. Clinical assessments: During each step of the study visit, during TUS to each target, clinical assessments will be made for each participant. These will be specific to the disease of interest and will be completed by a clinician. They will be filmed so that they can be assessed by blinded assessors after the study visit and allow for blinded quantification of TUS on clinical symptoms. A member of the research team will film assessments whilst a clinician completes them, and they will later scramble the video files to allow blinded assessment at a later date. Cognitive tasks include a dot direction discrimination task and for pain participants will include quantitative sensory testing. Motor tasks will include a stop signal task. During the TUS, Sham and Alternative brain target TUS, measurements will include EEG, Local Field Potentials (LFPs) recorded from the DBS electrodes, ECG.