DEMYELINATING DISEASES OF THE CENTRAL NERVOUS SYSTEM What Are Demyelinating Diseases? • Conditions that damage myelin, the protective sheath around nerves in the central nervous system (CNS). • Disrupt nerve conduction, causing varied neurologic symptoms. Key Demyelinating Diseases Covered: 1. Multiple Sclerosis (MS) 2. Neuromyelitis Optica Spectrum Disorder (NMOSD) 3. Myelin Oligodendrocyte Glycoprotein Antibody Disease (MOGAD) 4. Acute Disseminated Encephalomyelitis (ADEM) 5. Optic Neuritis 6. Transverse Myelitis Diagnostic Tools: • MRI: Key for lesion location, morphology. • CSF: Oligoclonal bands, cell count, protein. • Serologies: AQP4-IgG, MOG-IgG. • Evoked Potentials/OCT: Assess optic nerve damage. Multiple Sclerosis (MS) • Demographics: Young women, higher prevalence with distance from equator. • Clinical Types: - Relapsing-Remitting (RRMS) – most common - Secondary Progressive (SPMS) - Primary Progressive (PPMS) • Symptoms: Visual loss, diplopia, motor/sensory deficits, ataxia, vertigo. • Diagnosis: MRI (Dawson’s fingers), CSF oligoclonal bands, McDonald criteria. • Treatment: - Acute flares: Corticosteroids ± plasma exchange. - Disease-modifying therapies: Injectables, orals, monoclonal antibodies. - Symptom management: Fatigue, spasticity, gait, bladder issues, depression. Neuromyelitis Optica Spectrum Disorder (NMOSD) • Autoantibody: AQP4-IgG. • Target areas: Optic nerves, spinal cord, area postrema (nausea/hiccups). • MRI: Longitudinally extensive spinal cord lesions (>3 levels). • Treatment: - Acute: IV steroids ± plasma exchange. - Maintenance: Rituximab, eculizumab, satralizumab, etc. MOG Antibody Disease (MOGAD) • Autoantibody: MOG-IgG. • Features: Bilateral optic neuritis, myelitis (central cord, conus), ADEM. • Course: - Persistent MOG-IgG -> relapsing - Transient MOG-IgG -> monophasic • Treatment: Steroids, IVIg, plasma exchange; long-term with IVIg, rituximab. Acute Disseminated Encephalomyelitis (ADEM) • Population: Children/young adults. • Preceded by: Infection/vaccination. • Symptoms: Multifocal deficits, encephalopathy. • Imaging: Large T2 hyperintensities with open-ring enhancement. • Treatment: IV steroids ± IVIg/plasma exchange. Optic Neuritis • Presentation: Painful unilateral visual loss, often first MS symptom. • Exam findings: ↓ acuity, color vision, afferent pupillary defect. • Associated With: MS, NMOSD, MOGAD, autoimmune/infectious causes. • Treatment: IV steroids (for quicker recovery). Transverse Myelitis • Definition: Inflammation across the spinal cord. • Symptoms: Rapid weakness, sensory changes, bladder/bowel dysfunction. • Etiologies: MS, NMOSD, MOGAD, infection, autoimmune, paraneoplastic. • Imaging: T2 hyperintense spinal cord lesion; consider length and location. • Treatment: IV steroids ± plasma exchange. #Demyelinating #diseases #neurology #CNS #Differential #Diagnosis
