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

Not Applicable

Recruiting

• Conditions: Movement Disorders (Incl Parkinsonism); Stroke; Traumatic Brain Injury; Brain Diseases; Parkinson Disease; Essential Tremor, Movement Disorders

• Registration Number: NCT07056361
• Lead Sponsor: University of Pittsburgh

Brief Summary

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.

Study Timeline

• Study Start: 2022-12-16
• Study First Submitted: 2025-06-25
• Status Verified: 2025-07
• Study First Submitted QC: 2025-07-08
• Last Update Submitted: 2025-07-08
• Study First Posted: 2025-07-09
• Last Update Posted: 2025-07-09
• Primary Completion: 2026-12-31
• Study Completion: 2030-12-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 60

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Electromyography Activity	14 days	The investigators will record electromyography activity (EMG) to measure the motor evoked potentials of upper limb and facial muscles. At the end of the procedures these needles and/or the superficial adhesive electrodes will be removed. Based on the preliminary data, the investigators will consider the number of participants with at least an 18% increase in muscle activation as minimally acceptable.

Secondary Outcome Measures

Name	Time	Method
Facial Muscle Motor Function - Muscle Strength	14 days	The investigators will use electromyography (EMG) testing to measure muscle strength produced by the subject during isometric facial movements (e.g. smile, tongue out, puckered lips, and open-close mouth). Based on the preliminary data, the investigators will consider the number of participants with an increase of 50% in ROM as a minimally acceptable improvement in muscle strength.
Speech Intelligibility	14 days	The investigators will use the Assessment of Intelligibility of Dysarthric Speech (AIDS) to assess the quality of communication and intelligibility of speech at both word- and sentence-level. Intelligibility is calculated as the percentage of words correctly identified in the single-word task, and as the percentage of correctly transcribed words and speech rate (in words per minute) in the sentence task. Based on the preliminary data, the investigators will consider the number of participants with an improvement of 5% correctly transcribed to be minimally acceptable.
Dexterity of Articulation AMRs	14 days	The investigators will measure dexterity of articulation by alternating motion rates (AMRs) of the repetitive plosive sound (pah, tah, and kah). Based on the preliminary data, the investigators will consider the number of participants with an improvement of 10% in the rate to be minimally acceptable.
Dexterity of Articulation SMRs	14 days	The investigators will measure dexterity of articulation by sequential motion rates (SMRs) of the repetitive plosive sound (pah, tah, and kah). Based on the preliminary data, the investigators will consider the number of participants with an improvement of 10% in the rate to be minimally acceptable.
Facial Muscle Motor Function - Range of Motion	14 days	The investigators will use electromyography (EMG) testing to measure range of motion produced by the subject during isometric facial movements (e.g. smile, tongue out, puckered lips, and open-close mouth). Based on the preliminary data, the investigators will consider the number of participants with an increase of 50% in ROM as a minimally acceptable improvement.

Trial Locations

Locations (1)

University of Pittsburgh; 🇺🇸 Pittsburgh, Pennsylvania, United States