Related Experiment Video
Updated: Oct 4, 2025
12:23
Dynamic Visual Tests to Identify and Quantify Visual Damage and Repair Following Demyelination in Optic Neuritis Patients
Published on: April 14, 2014
14.2K
Anterior optic pathway pathology in CNS demyelinating diseases
Marco Pisa1, Jonathan Pansieri1, Sydney Yee1
1Nuffield Department of Clinical Neurosciences, University of Oxford, Level 6 West Wing, John Radcliffe Hospital, Oxford, UK.
Brain : a Journal of Neurology
|February 8, 2022
Summary
Chronic inflammation and neurodegeneration are common in the optic pathway in multiple sclerosis and neuromyelitis optica, even without overt optic neuritis. This explains progressive vision loss seen in optical coherence tomography studies.
Area of Science:
- Neuroimmunology
- Neuro-ophthalmology
- Neuroinflammation
Background:
- The anterior optic pathway is frequently affected in CNS inflammatory demyelinating diseases like multiple sclerosis (MS) and neuromyelitis optica (NMO).
- Optic neuritis is a common symptom, but subclinical optic nerve involvement with progressive neuroretinal thinning is also observed, with underlying pathology poorly understood.
Purpose of the Study:
- To investigate the pathological substrate of optic pathway involvement in MS, NMO spectrum disorder (NMOSD), and acute disseminated encephalomyelitis (ADEM).
- To assess the extent and distribution of demyelination, inflammation, and axonal injury along the anterior optic pathway.
Main Methods:
- Post-mortem analysis of optic nerves, chiasms, and tracts from 29 MS, 6 NMOSD, 6 ADEM cases, and 5 controls.
- Immunolabeling for myelin, inflammation (microglia/macrophages, T- and B-cells, complement), acute axonal injury, and astrocytes.
- Assessment of marker distribution in parenchymal, perivascular, and meningeal compartments; classification of demyelinated plaques as active.
Main Results:
- In MS, 82.8% of cases had demyelination (75% active), with frequent inflammation and axonal injury, particularly in the optic nerves.
- NMOSD cases with prior optic neuritis showed extensive demyelination; those without showed inflammation and axonal injury without demyelination.
- Chronic inflammation and axonal injury were prevalent across disease stages and compartments, suggesting ongoing neurodegeneration.
Conclusions:
- Chronic inflammation and subsequent neurodegeneration occur in the optic pathway in MS and NMOSD, irrespective of disease stage or overt optic neuritis.
- Findings broaden the understanding beyond plaque-centric views, explaining progressive neuroretinal changes seen in optical coherence tomography.
- The anterior optic pathway is a critical site for inflammatory and neurodegenerative processes in these CNS demyelinating diseases.
Related Concept Videos
01:22Photoreceptors and Visual Pathways
6.7K
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category,...
6.7K
01:29Overview of Somatic Sensory Pathways
6.2K
Somatic sensory or somatosensory pathways refer to the neural pathways that carry information related to touch, pressure, pain, temperature, and proprioception from the skin, muscles, tendons, and joints to the brain. These pathways involve several stages of processing and integration of sensory information.
The somatosensory system is divided into three main pathways: the dorsal (or posterior) column-medial lemniscus, spinothalamic (or anterolateral), and spinocerebellar pathways.
The dorsal...
The somatosensory system is divided into three main pathways: the dorsal (or posterior) column-medial lemniscus, spinothalamic (or anterolateral), and spinocerebellar pathways.
The dorsal...
6.2K
01:28Major Somatic Sensory Pathways
1.3K
Sensory impulses related to touch, pressure, vibration, and proprioception from various body parts, such as the limbs, trunk, neck, and posterior head, travel to the cerebral cortex through the posterior column-medial lemniscus pathway. The pathway’s name derives from the two white-matter tracts that convey the impulses: the spinal cord's posterior column and the brainstem's medial lemniscus. First-order sensory neurons extend their axons into the spinal cord, forming the...
1.3K
01:11Direct Motor Pathways
2.7K
The direct motor pathways, also known as the pyramidal tracts, are a group of neural pathways that originate in the brain and descend through the spinal cord. They control the voluntary movement of the body. There are two major direct motor pathways: the corticospinal and the corticobulbar tracts.
The corticospinal tract is responsible for the voluntary movement of the limbs and trunk. It originates in the cerebral cortex of the brain and descends through the cerebrum's internal capsule and...
The corticospinal tract is responsible for the voluntary movement of the limbs and trunk. It originates in the cerebral cortex of the brain and descends through the cerebrum's internal capsule and...
2.7K
01:15Parkinson's Disease: Overview
804
Neurodegenerative disorders are progressive diseases that cause irreversible damage and loss to neurons in specific brain areas. Examples of these disorders include Parkinson's disease, Alzheimer's disease, Multiple Sclerosis (MS), and Amyotrophic Lateral Sclerosis (ALS). These disorders share characteristics such as proteinopathies, selective neuronal vulnerability, and a complex interplay between genetic and environmental factors. The primary therapeutic goal for these conditions is...
804
01:03Olfactory Receptors: Location and Structure
9.8K
The process of olfaction, also known as the sense of smell, is a sophisticated chemical response system. The specialized sensory neurons that facilitate this process, known as olfactory receptor neurons, are situated in an upper segment of the nasal cavity, known as the olfactory epithelium. Olfactory sensory neurons are bipolar, with their dendrites extending from the epithelium's apex into the mucus that lines the nasal cavity. Airborne molecules, when inhaled, traverse the olfactory...
9.8K