Demyelinating Dx

Question 1

What is a demyelinating disease?

Answer 1

A disease that affects the myelin sheath surrounding neurons in the CNS or PNS, leading to impaired signal transmission.

Question 2

What are the two major types of demyelinating diseases based on the nervous system affected?

Answer 2

Demyelinating diseases of the CNS and demyelinating diseases of the PNS.

Question 3

What are the key functions of myelin in the nervous system?

Answer 3

Myelin insulates axons and facilitates faster signal transmission.

Question 4

What cells produce myelin in the CNS?

Answer 4

Oligodendrocytes.

Question 5

What cells produce myelin in the PNS?

Answer 5

Schwann cells.

Question 6

What are the classifications of demyelinating diseases based on pathogenesis?

Answer 6

Demyelinating myelinoclastic (destruction of myelin) and demyelinating leukodystrophic (abnormal myelin formation).

Question 7

What are examples of central demyelinating diseases?

Answer 7

Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), acute disseminated encephalomyelitis (ADEM).

Question 8

What are examples of peripheral demyelinating diseases?

Answer 8

Guillain-Barré syndrome (AIDP), chronic inflammatory demyelinating polyneuropathy (CIDP), Charcot-Marie-Tooth disease.

Question 9

What is multiple sclerosis (MS)?

Answer 9

An immune-mediated inflammatory disease affecting the myelinated axons of the CNS, leading to demyelination and neurological disability.

Question 10

What is the hallmark of multiple sclerosis?

Answer 10

Dissemination in time and space, with relapsing-remitting episodes of demyelination in different CNS areas.

Question 11

What are common sensory symptoms of multiple sclerosis?

Answer 11

Paresthesia, tingling, hyperalgesia, and Lhermitte’s sign.

Question 12

What is Lhermitte’s sign?

Answer 12

An electric shock-like sensation down the spine with neck flexion, seen in MS.

Question 13

What are common motor symptoms of multiple sclerosis?

Answer 13

Muscle cramps, spasticity, and weakness.

Question 14

What are common cerebellar signs in multiple sclerosis?

Answer 14

Charcot’s triad: scanning speech, nystagmus, and intentional tremor.

Question 15

What cranial nerve involvement is common in MS?

Answer 15

Optic neuritis, facial nerve palsy, trigeminal neuralgia, and diplopia.

Question 16

What autonomic dysfunctions occur in multiple sclerosis?

Answer 16

Bladder incontinence, bowel dysfunction, and sexual dysfunction.

Question 17

What cognitive impairments are associated with multiple sclerosis?

Answer 17

Slowed mental processing, memory loss, aphasia, and dysphasia.

Question 18

What is the primary pathophysiology of multiple sclerosis?

Answer 18

Destruction of oligodendrocytes, formation of plaques, and axonal degeneration.

Question 19

What imaging modality is most useful for diagnosing multiple sclerosis?

Answer 19

MRI of the brain and spinal cord with contrast.

Question 20

What is McDonald’s criteria?

Answer 20

A diagnostic criteria for MS that includes clinical, imaging, and ancillary test findings.

Question 21

What are the first-line disease-modifying therapies for MS?

Answer 21

Interferon beta, glatiramer acetate, and monoclonal antibodies (e.g., natalizumab, ocrelizumab).

Question 22

What symptomatic treatments are used in MS?

Answer 22

Muscle relaxants for spasticity, corticosteroids for acute relapses, and bladder control medications.

Question 23

What is neuromyelitis optica spectrum disorder (NMOSD)?

Answer 23

An inflammatory demyelinating disease affecting the optic nerves, brainstem, and spinal cord.

Question 24

What antibody is associated with NMOSD?

Answer 24

Aquaporin-4 (AQP4) IgG.

Question 25

What are the core clinical features of NMOSD?

Answer 25

Optic neuritis, acute myelitis, area postrema syndrome (hiccups, nausea, vomiting), brainstem syndrome.

Question 26

Why is it important to differentiate NMOSD from MS?

Answer 26

Some MS treatments, such as interferon beta, can worsen NMOSD.

Question 27

What imaging findings support NMOSD diagnosis?

Answer 27

Longitudinally extensive transverse myelitis (≥3 vertebral segments on MRI).

Question 28

What is acute inflammatory demyelinating polyneuropathy (AIDP)?

Answer 28

The most common form of Guillain-Barré syndrome, an autoimmune disorder causing rapid-onset muscle weakness and areflexia.

Question 29

What infections are associated with AIDP?

Answer 29

Campylobacter jejuni, herpes virus, Mycoplasma, enteric viruses.

Question 30

What are the key clinical features of AIDP?

Answer 30

Progressive weakness starting in the lower limbs, areflexia, and autonomic dysfunction.

Question 31

What are variants of AIDP?

Answer 31

Miller-Fisher syndrome (ophthalmoplegia, ataxia, areflexia), pharyngeal-cervico-brachial variant, acute motor axonal neuropathy (AMAN).

Question 32

What is the hallmark CSF finding in AIDP?

Answer 32

Albuminocytologic dissociation (elevated protein with normal WBC count).

Question 33

What is the main treatment for AIDP?

Answer 33

Intravenous immunoglobulin (IVIG) or plasma exchange.

Question 34

What is chronic inflammatory demyelinating polyneuropathy (CIDP)?

Answer 34

A chronic autoimmune demyelinating polyneuropathy with gradual progression over months.

Question 35

How is CIDP different from AIDP?

Answer 35

CIDP has an insidious onset and prolonged course, while AIDP is acute and self-limiting.

Question 36

What are the diagnostic tests for CIDP?

Answer 36

CSF analysis (high protein, normal WBC), nerve conduction studies, nerve biopsy.

Question 37

What is the first-line treatment for CIDP?

Answer 37

IVIG, corticosteroids, and plasma exchange.

Question 38

What is osmotic demyelination syndrome?

Answer 38

A demyelination disorder due to rapid correction of hyponatremia, leading to central pontine myelinolysis.

Question 39

What is progressive multifocal leukoencephalopathy (PML)?

Answer 39

A severe CNS demyelinating disease caused by JC virus in immunocompromised patients.

Question 40

What is subacute sclerosing panencephalitis (SSPE)?

Answer 40

A fatal progressive demyelinating disease caused by persistent measles virus infection.

Question 41

What is Charcot-Marie-Tooth disease?

Answer 41

A hereditary demyelinating polyneuropathy affecting peripheral nerves, leading to progressive weakness and foot deformities.

Question 42

What are the most common causes of demyelinating diseases?

Answer 42

Autoimmune disorders, infections, toxins, genetic mutations, and metabolic disorders.

Question 43

Which dietary deficiency can cause demyelination?

Answer 43

Copper deficiency.

Question 44

What is POEMS syndrome?

Answer 44

A paraneoplastic syndrome with polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes.

Question 45

What is the treatment approach for demyelinating diseases?

Answer 45

Immunomodulation, symptomatic relief, neurorehabilitation, and supportive care.

Question 46

What is the prognosis of MS?

Answer 46

Variable; some patients have mild disease, while others develop significant disability.

Question 47

What is the prognosis of AIDP?

Answer 47

Most patients recover within weeks to months, but some have residual weakness.