Demyelinating, Autoimmune, and Neuroinflammatory Disease
Immune-Mediated Injury in the Nervous System
Pathobiology
Inflammatory neurologic disorders arise when adaptive and innate immune mechanisms target myelin, axons, synapses, or glial support systems. Disease expression depends on antigen specificity, compartmentalized inflammation, blood-brain barrier dynamics, and repair capacity.
Major Immune-Mediated Disorders
Multiple sclerosis
- Chronic CNS demyelination with inflammatory and neurodegenerative components
- Often disseminated in time and space
- MRI and CSF support diagnosis
Neuromyelitis optica spectrum disorder
- Often associated with aquaporin-4 antibodies
- Targets astrocytic water channels
- May have severe optic neuritis and longitudinal myelitis
Biomarkers and Imaging
Which finding best supports active inflammatory demyelination in multiple sclerosis?
Enhancement suggests active lesion inflammation and barrier disruption.
Correct answer: Gadolinium-enhancing lesions on MRI
Why are neurofilament light chain levels of interest in modern neuroimmunology?
They are not fully disease-specific but are promising quantitative injury markers.
Correct answer: They may reflect the degree of neuroaxonal injury and help track disease activity or treatment response.
Evaluating Suspected CNS Autoimmunity
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Step 1: Determine whether the syndrome localizes to optic nerve, spinal cord, brainstem, cortex, or multifocal CNS tissue.
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Step 2: Assess time course, relapse pattern, and recovery.
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Step 3: Obtain MRI and cerebrospinal fluid studies.
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Step 4: Test for disease-defining antibodies where indicated.
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Step 5: Select acute immunotherapy and long-term relapse prevention.
A longitudinally extensive transverse myelitis should raise particular concern for which disorder?
Longitudinally extensive myelitis is a classic clue to neuromyelitis optica spectrum disorder.
Correct answer: Aquaporin-4 antibody-associated disease
Open Problems
Major research questions include how inflammation transitions to neurodegeneration, which biomarkers best predict disability, how remyelination fails, and how to stratify patients for highly targeted immunotherapies.