Demyelinating Dx Flashcards
What is a demyelinating disease?
A disease that affects the myelin sheath surrounding neurons in the CNS or PNS, leading to impaired signal transmission.
What are the two major types of demyelinating diseases based on the nervous system affected?
Demyelinating diseases of the CNS and demyelinating diseases of the PNS.
What are the key functions of myelin in the nervous system?
Myelin insulates axons and facilitates faster signal transmission.
What cells produce myelin in the CNS?
Oligodendrocytes.
What cells produce myelin in the PNS?
Schwann cells.
What are the classifications of demyelinating diseases based on pathogenesis?
Demyelinating myelinoclastic (destruction of myelin) and demyelinating leukodystrophic (abnormal myelin formation).
What are examples of central demyelinating diseases?
Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), acute disseminated encephalomyelitis (ADEM).
What are examples of peripheral demyelinating diseases?
Guillain-Barré syndrome (AIDP), chronic inflammatory demyelinating polyneuropathy (CIDP), Charcot-Marie-Tooth disease.
What is multiple sclerosis (MS)?
An immune-mediated inflammatory disease affecting the myelinated axons of the CNS, leading to demyelination and neurological disability.
What is the hallmark of multiple sclerosis?
Dissemination in time and space, with relapsing-remitting episodes of demyelination in different CNS areas.
What are common sensory symptoms of multiple sclerosis?
Paresthesia, tingling, hyperalgesia, and Lhermitte’s sign.
What is Lhermitte’s sign?
An electric shock-like sensation down the spine with neck flexion, seen in MS.
What are common motor symptoms of multiple sclerosis?
Muscle cramps, spasticity, and weakness.
What are common cerebellar signs in multiple sclerosis?
Charcot’s triad: scanning speech, nystagmus, and intentional tremor.
What cranial nerve involvement is common in MS?
Optic neuritis, facial nerve palsy, trigeminal neuralgia, and diplopia.
What autonomic dysfunctions occur in multiple sclerosis?
Bladder incontinence, bowel dysfunction, and sexual dysfunction.
What cognitive impairments are associated with multiple sclerosis?
Slowed mental processing, memory loss, aphasia, and dysphasia.
What is the primary pathophysiology of multiple sclerosis?
Destruction of oligodendrocytes, formation of plaques, and axonal degeneration.
What imaging modality is most useful for diagnosing multiple sclerosis?
MRI of the brain and spinal cord with contrast.
What is McDonald’s criteria?
A diagnostic criteria for MS that includes clinical, imaging, and ancillary test findings.
What are the first-line disease-modifying therapies for MS?
Interferon beta, glatiramer acetate, and monoclonal antibodies (e.g., natalizumab, ocrelizumab).
What symptomatic treatments are used in MS?
Muscle relaxants for spasticity, corticosteroids for acute relapses, and bladder control medications.
What is neuromyelitis optica spectrum disorder (NMOSD)?
An inflammatory demyelinating disease affecting the optic nerves, brainstem, and spinal cord.
What antibody is associated with NMOSD?
Aquaporin-4 (AQP4) IgG.
What are the core clinical features of NMOSD?
Optic neuritis, acute myelitis, area postrema syndrome (hiccups, nausea, vomiting), brainstem syndrome.
Why is it important to differentiate NMOSD from MS?
Some MS treatments, such as interferon beta, can worsen NMOSD.
What imaging findings support NMOSD diagnosis?
Longitudinally extensive transverse myelitis (≥3 vertebral segments on MRI).
What is acute inflammatory demyelinating polyneuropathy (AIDP)?
The most common form of Guillain-Barré syndrome, an autoimmune disorder causing rapid-onset muscle weakness and areflexia.
What infections are associated with AIDP?
Campylobacter jejuni, herpes virus, Mycoplasma, enteric viruses.
What are the key clinical features of AIDP?
Progressive weakness starting in the lower limbs, areflexia, and autonomic dysfunction.
What are variants of AIDP?
Miller-Fisher syndrome (ophthalmoplegia, ataxia, areflexia), pharyngeal-cervico-brachial variant, acute motor axonal neuropathy (AMAN).
What is the hallmark CSF finding in AIDP?
Albuminocytologic dissociation (elevated protein with normal WBC count).
What is the main treatment for AIDP?
Intravenous immunoglobulin (IVIG) or plasma exchange.
What is chronic inflammatory demyelinating polyneuropathy (CIDP)?
A chronic autoimmune demyelinating polyneuropathy with gradual progression over months.
How is CIDP different from AIDP?
CIDP has an insidious onset and prolonged course, while AIDP is acute and self-limiting.
What are the diagnostic tests for CIDP?
CSF analysis (high protein, normal WBC), nerve conduction studies, nerve biopsy.
What is the first-line treatment for CIDP?
IVIG, corticosteroids, and plasma exchange.
What is osmotic demyelination syndrome?
A demyelination disorder due to rapid correction of hyponatremia, leading to central pontine myelinolysis.
What is progressive multifocal leukoencephalopathy (PML)?
A severe CNS demyelinating disease caused by JC virus in immunocompromised patients.
What is subacute sclerosing panencephalitis (SSPE)?
A fatal progressive demyelinating disease caused by persistent measles virus infection.
What is Charcot-Marie-Tooth disease?
A hereditary demyelinating polyneuropathy affecting peripheral nerves, leading to progressive weakness and foot deformities.
What are the most common causes of demyelinating diseases?
Autoimmune disorders, infections, toxins, genetic mutations, and metabolic disorders.
Which dietary deficiency can cause demyelination?
Copper deficiency.
What is POEMS syndrome?
A paraneoplastic syndrome with polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes.
What is the treatment approach for demyelinating diseases?
Immunomodulation, symptomatic relief, neurorehabilitation, and supportive care.
What is the prognosis of MS?
Variable; some patients have mild disease, while others develop significant disability.
What is the prognosis of AIDP?
Most patients recover within weeks to months, but some have residual weakness.
