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Deep Brain Stimulation for Visuomotor Function in Parkinson's Disease

Deep Brain Stimulation for Visuomotor Function in Parkinsons Disease

Status
Recruiting
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT05400499
Acronym
DBS visuomotor
Enrollment
40
Registered
2022-06-01
Start date
2022-10-04
Completion date
2026-07-01
Last updated
2026-01-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Parkinson's Disease

Keywords

Parkinson's disease, Deep brain stimulation, Subthalamic nucleus

Brief summary

Inability to align and refocus the eyes on the objects at different depths, i.e., vergence impairment, frequently affects the quality of life in patients with Parkinson's disease. Our study aims to understand the location-specific effects of subthalamic region deep brain stimulation on vergence by integrating the patient-specific deep brain stimulation models and high-resolution eye-tracking measures. The knowledge gained will allow us to find the most beneficial stimulation location and parameters for improving binocular coordination and vergence while preserving the ability to treat motor symptoms in Parkinson's disease.

Detailed description

The victims of very common condition Parkinson's disease (PD) are known to have tremor, rigidity, and slow movements. PD, in addition to its effects on human movements, also affects many other aspect of the brain's function. Impairment of vision is frequently seen in PD. These patients have difficulties with holding their eyes steady at a given point, seamlessly look around and read, and refocus their eyes from one image to the other while looking at objects that are at different depths. About third of the PD patients have problems coordinating the movement of two eyes together, i.e., abnormal vergence. Latter results in disabling double vision and abnormal depth perception. Most treatment options available to PD patients are limited to their effects on tremor, stiffness, and slowness - their effects on visual function is very limited. Eye surgeries are not ideal treatment strategies for these conditions given constantly changing state of the PD brain due to its degenerative nature. Cutting edge deep brain stimulation (DBS) surgery has variable effects on the eye movements and vergence function in PD. The goal of our research program is to identify the best possible therapeutic strategy using DBS to improve vergence eye movements in PD while continuing to offer its other benefits. Our multidisciplinary program has two aspects. One part of the study will examine the effects of DBS on vergence abnormalities affecting their ability to focus at various depths. Using state of art, high-resolution, research grade ophthalmic equipment the investigators will examine fine details of how DBS alters the patients' ability to refocus and how it changes the alignment between the two eyes that can cause double vision and abnormal depth perception. Once the investigators identify these characteristic changes, the investigators will correlate them with the stimulated anatomical location within the same patient's brain determined using combination of novel computer simulations of DBS and the patient's own MRI. The knowledge gained will allow us to find the ideal stimulation locations that is most beneficial to the patient for improvement in vision while continuing to offer benefits for tremor, rigidity, and slow movements.

Interventions

None listed

Sponsors

VA Office of Research and Development
Lead SponsorFED

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Healthy volunteers
No

Inclusion criteria

* Parkinson's disease with bilateral STN DBS * Availability of pre-operative MR images (with a T1-weighted, gradient-echo sequence) and ability to get post-operative MRI or CT scans * Hoehn and Yahr stage 2-4 when off medication, and a stable antiparkinsonian medication regimen and DBS parameter settings

Exclusion criteria

* Previous surgical therapy for Parkinson's disease (other than DBS) * Dementia * Clinically significant untreated depression or anxiety * Clinical features suggestive of atypical parkinsonism

Design outcomes

Primary

MeasureTime frameDescription
Eye alignmentonce at the time of experiment, for 1 hourThe investigators will measure dynamic eye alignment (vergence, the difference between the horizontal angular positions of the right and left eye) with non-invasive high-resolution video oculography. Derives parameters such as ratio of actual versus desired vergence, delay of vergence onset after target shift, peak vergence velocity, and congruency between the two eyes will be incorporated in an equation. The equation output will be used as a measure of the effects of subthalamic region deep brain stimulation on vergence parameters.

Countries

United States

Contacts

Primary ContactAasef G Shaikh, MD PhD
Aasef.Shaikh@va.gov(216) 791-3800
Backup ContactMonica O'Loughlin
Monica.O'Loughlin@va.gov(216) 791-3800

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026