By Dave DeFusco
Advanced imaging and diagnostic tools could pave the way for more personalized and effective approaches to managing Multiple Sclerosis, according to study published in the Journal of Neurology.
Multiple sclerosis (MS), a chronic autoimmune disease, often manifests itself through visual pathway disturbances, including optic neuritis, macular dysfunction, demyelination and inflammation.
鈥淭hese disturbances not only impair vision but are also indicative of broader neural damage and disease progression,鈥 said Dr. Marissa Barrera, a co-author of the study and director of the M.S. in Speech-Language Pathology at the Katz School. 鈥淓arly visual symptoms, such as optic neuritis, frequently precede an MS diagnosis, making the visual pathway a critical area of study.鈥
Visual impairments in people with MS often correlate with a decline in quality of life by affecting activities that rely on perception, coordination and cognitive processing. Three key clinical tools have emerged for evaluating visual pathway disturbances in MS:
- Magnetic Resonance Imaging (MRI): Widely used to diagnose and monitor Multiple Sclerosis, MRI reveals demyelination in the optic chiasm, a cross-shaped structure in the brain where the optic nerves from each eye meet, and tissue disturbances in the occipital cortex, which are linked to slower processing speeds and cognitive decline.
- Optical Coherence Tomography (OCT): This non-invasive imaging technique provides high-resolution images of retinal structures. It has demonstrated effectiveness comparable to MRI in measuring damage to the optic nerve and retina. Disturbances in the retinal nerve fiber layer and macula, as detected by OCT, have been associated with cognitive impairment.
- Visual Evoked Potentials (VEP): By measuring the brain's response to visual stimuli, Visual Evoked Potentials assess functional disturbances in the visual pathway. Delayed P100 latency, a key VEP component, indicates demyelination and has been linked to reduced gray and white matter and cognitive decline.
The study, 鈥淧eering Further into the Mind鈥檚 Eye: Combining Visual Evoked Potential and Optical Coherence Tomography Measures Enhances Insight into the Variance in Cognitive Functioning in Multiple Sclerosis,鈥 suggests that combining OCT and VEP measurements would provide superior insights into cognitive dysfunction in people with MS compared to using either tool alone.
OCT captures structural abnormalities, while VEP measures functional disruptions. Together, these methods offer a comprehensive view of neural structure-function relationships, potentially predicting cognitive outcomes and identifying patients suitable for targeted rehabilitation.
The researchers used OCT and VEP data to study three measures of retinal volume and the speed of VEP responses, comparing them to how well people performed on cognitive tests. Cognitive domains that they assessed included executive function, attention, processing speed and visual-spatial abilities. Key findings include:
- Correlations Between Visual Metrics and Cognition: Both OCT and VEP measures showed statistically significant associations with cognitive performance. For instance, lower retinal nerve fiber layer volume and delayed VEP latency correlated with poorer cognitive scores.
- Predictive Power of Combined Measures: Regression analyses revealed that combining OCT and VEP data modestly but significantly improved predictions of global cognitive performance and specific domains such as visual-spatial abilities and executive functioning.
- Identifying Risk Profiles: People with MS who have both delayed VEP latency and reduced retinal volume exhibited the most pronounced cognitive deficits, highlighting the potential for these measures to identify high-risk individuals.
The study underscores the potential of OCT and VEP as complementary tools in the clinical assessment of MS. By providing detailed insights into visual pathway dysfunction, these methods can predict cognitive decline more accurately, assist in early identification of patients at risk for severe cognitive impairment and guide personalized rehabilitation and therapeutic interventions.
鈥淭he integration of these tools into routine MS management could enhance understanding of disease progression and inform the development of restorative treatments,鈥 said Dr. Thomas Covey, lead author of the study and an assistant professor in the Department of Neurology at the University of Bufalo. 鈥淎s these measures become increasingly integrated into clinical settings, they offer hope for earlier diagnosis, personalized care and better quality of life for people with MS.鈥
