Clinical trial NCT06352086: Understanding Visual Processing After Occipital Stroke
Official title: Understanding Visual Processing After Occipital Stroke
Study type: OBSERVATIONAL
Overall status: WITHDRAWN
Conditions: Vision Loss Partial
Vision; Loss, Both Eyes
Hemianopia, Homonymous
Hemianopia
Quadrantanopia
Stroke, Ischemic
Stroke - Occipital Infarction
Cortical Blindness
Occipital Lobe Infarct
Peripheral Visual Field Defect of Both Eyes
Keywords: Occipital stroke
Vision loss after stroke
Vision recovery
Vision restoration
Partial vision loss
vision loss
Lead sponsor: University of Rochester
Sponsor class: OTHER
First posted: 2024-04-08
Enrollment: 0
Sex: ALL
Minimum age (years): 21
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Subjects will all be individuals who have sustained partial vision loss after an occipital lobe stroke.

Brief summary: The purpose of this study is to investigate how visual orientation discrimination and metacognition (i.e., perceptual confidence) are affected by occipital stroke that causes hemianopia and quadrantanopia in adults. This research will provide insight as to how the residual visual system, which not directly damaged by the occipital stroke, processes orientation (assayed in terms of orientation discrimination) and metacognition (by measuring perceptual confidence for orientation discrimination). These measures will be used to refine computational models that attempt to explain how the brain copes with loss of primary visual cortex (V1) as a result of stroke. This knowledge is essential to devise more effective visual rehabilitation therapies for patients suffering from occipital strokes.


Eligibility criteria: Inclusion Criteria:

* Residents of the United States or Canada
* MRI and/or CT scans showing unilateral stroke or stroke-like damage to primary visual cortex or its immediate afferent white matter sustained 1-year or more prior to enrollment
* Reliable visual field defects in both eyes as measured by Humphrey, Macular Integrity Assessment (MAIA), Goldmann, and/or equivalent perimetry. This deficit must be large enough to enclose a 5-deg diameter visual stimulus.
* Ability to fixate on visual targets reliably for 1000ms (as demonstrated by visual fields, and verified in study participation)
* Willing, able, and competent to provide informed consent
* Cognitively able to understand and respond to written and oral instructions in English

Exclusion Criteria:

* Past or present ocular disease interfering with visual acuity
* Corrected vision worse than 20/40 in either eye
* Presence of damage to the dorsal Lateral Geniculate Nucleus
* Diffuse, whole brain degenerative processes
* Brain damage deemed by study staff to potentially interfere with testing ability or outcome measures
* Documented history of traumatic brain injury
* Documented history of drug/alcohol abuse
* Current use neuroactive
* Cognitive or seizure disorders
* Subjects with one-sided attentional neglect

Primary outcomes:
measure: Orientation discrimination threshold
timeFrame: Baseline
measure: Perceptual Confidence in Orientation Discrimination
timeFrame: Baseline
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
References: