Stimulating Specific Brain Areas (VOP/VIM) With Electricity to Improve Movement and Muscle Control

Official title

VOP/VIM Direct Electrical Stimulation Increases Motor Cortex Excitability and Motor Output

Overview

In this study the investigators aim to enroll patients scheduled to undergo deep brain stimulation (DBS) implantation for movement disorders for intra-operative testing. In addition to standard-of-care surgical procedure to implant deep brain stimulation electrode leads, participants will also be stimulated and recorded from cortical areas by a temporary strip electrode (1X6) in the subdural space. The electrodes will be connected to external stimulators and a series of experiments will be performed to assess effects of the DBS on movement quality and electrophysiology measures. Results of this study will elucidate the biological mechanisms related to deep brain stimulation in modulating motor and speech function in patients with abnormal movement disorders.

Detailed description

In this study the investigators aim to enroll patients for intra-operative testing. Specifically, the investigators will recruit patients already undergoing DBS implantation for movement disorders. In addition to standard-of-care subcortical mapping using micro-electrode recording (MER) and macro-stimulation mapping during DBS placement, cortical local field potentials (LFPs) will be simultaneously recorded from primary motor (M1) and somatosensory (S1) cortical areas by placement of a temporary strip electrode (1X6) in the subdural space. Appropriate localization of this grid over M1 and S1 will be confirmed by the so-called phase-reversal of somatosensory evoked potentials (SSEPs). Once M1 is localized, the strip electrode over M1 will be used to produce motor evoked potentials to contralateral hand muscles from direct cortical stimulation (DCMEPs). The stimulation threshold of the DCMEPs will be used as a direct measure of the excitability of the cortical spinal tract and compared with and without stimulation of the VOP/VIM nuclei. Cortical and subcortical LFPs will be obtained alongside electromyographic (EMG) data while the patient performs contralateral upper extremity movement tasks measuring velocity, grip strength, and strength modulation and while the patient perform a variety of articulation exercises. Along with the DCMEP stimulation thresholds, these parameters of motor output will be obtained both with and without VOP/VIM stimulation to assess for stimulation induced potentiation of motor output.

Interventions

• Device Direct cortical stimulation and deep brain stimulation of motor thalamus
  All participants enrolled will undergo implantation of deep brain stimulation electrode leads for treatment of movement disorders. In addition to standard-of-care subcortical mapping using micro-electrode recording (MER) and macrostimulation mapping during DBS placement, cortical local field potentials (LFPs) will be simultaneously recorded from primary motor (M1) and somatosensory (S1) cortical areas by placement of a temporary strip electrode (1X6) in the subdural space. The strip electrode ov

Primary outcome measures

• Electromyography Activity [Time frame: 14 days]

Secondary outcome measures (5)

• Facial Muscle Motor Function - Muscle Strength [Time frame: 14 days]
• Facial Muscle Motor Function - Range of Motion [Time frame: 14 days]
• Speech Intelligibility [Time frame: 14 days]
• Dexterity of Articulation AMRs [Time frame: 14 days]
• Dexterity of Articulation SMRs [Time frame: 14 days]

Eligibility criteria

Inclusion criteria

• Essential tremor patients who are scheduled to undergo deep brain stimulation surgery at UPMC Presbyterian with asymmetric essential tremor symptoms will be included, with the tested limb corresponding to the least affected arm to better approximate normal function. These patients are implanted bilaterally regardless of symptom laterality, as the natural history of essential tremor indicates eventual bilateral symptoms.
• Parkinson's Disease patients who are scheduled to undergo deep brain stimulation surgery at UPMC Presbyterian with a history of Parkinson's Disease will also be recruited for intra-operative stimulation of their STN-targeted implants, to assess if VIM/VOP has high specificity for improving motor output.

Confirmation that subjects' terms of insurance coverage for their standard of care procedure will not be altered by study enrollment.

Exclusion criteria

• Patients will be excluded from the study if there is any seizure history, to avoid the increased epileptogenic risk of intraoperative stimulation.
• Patients with significant bilateral tremor that precludes completion of motor tasks.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Basic science

Study locations

United States · 1 center

• University of Pittsburgh — Pittsburgh

Identifiers

NCT: NCT07056361 · STUDY22100174

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗