Demyelinating D/O Flashcards
Pathogenesis of Myasthenia Gravis
Type V (II-B) hypersensitivity reaction:
Abnormal Myoid tissue originating from Thymus recognized as foreign by B/T cells
These antibodies bind to Achetylecholine receptors
(AchR modulating, blocking, binding, anti-MUSK, etc)
Myasthenia Gravis:
MUSK (+) versus MUSK (-) patients
Significantly more:
Bulbar Weakness
Respiratory crises
Electrodiagnostic findings may be localized
Resistant to treatment (Plasma Exchange best option)
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Phases (3) and Pathogenesis (5) of MS
Phases
- inflammatory initiating event
- recovery
- chronic progression
Pathogenesis
- Immune cells activated in peripheral lymphoid tissue
- Egress of activated T(?B) cells into circulation
- Adherance to surface molecules on vascular endothelium
- entry through BBB
- Immune-mediated damage within CNS
Risk of patient of Optic Neuritis will Develop MS
Pathologic Subtypes of MS
Pattern I
Pattern II
Pattern III
Pattern IV
- Pattern I:
- T-Cell and macrophage infiltrates centered around vessels
- Oligodendrocytes = Spared
- NO compliment activation
- Pattern II (more common) :
- T-cells and macrophage infiltrates centered around vessels
- Oligodendrocytes = Spared
- YES compliment activation / immunoglobulin deposition
- Pattern III:
- Apoptosis of Oligodendrocytes
- Sparing of perivascular spaces
- Pattern IV:
- non-apoptotic oligodendrocyte death
Interferon Beta:
- Mechanism of Action
- Adverse effects
- Transcriptional regulator of >1000 genes, but exact effect on MS is unknown
- Adverse effects:
- Common:
- Skin reactions
- Fever
- Myalgia
- Headache
- Severe
- Liver toxicity
- Common:
Glatiramer Acetate
- Proposed MoA’s (5)
- Adverse effects
- Proposed MoA
- Competitive binding with APCs
- Preferred bindng of GA-MHC complex compared to MBC-MHC complex to T-cells
- Induction of tolerance in T-cells
- Expression of neurotropic factors
- Stimulation of neurogenesis
- Adverse effects
- Injection site reaction
- Allergic Reaction
- flushing/palpitations (scary but transient)
Natalizumab
- MoA
- Adverse Effects
MoA
- alpha 4 integrin antagonist
- Possible suppresssion of existing inflammation within lesion
- inhibits microglial activation
- induces apoptosis of alpha4 integrin expression
Adverse Effects
- Fatigue
- Allergic reaction
- infusion reaction
- PML - especially if JC virus (+)
Risk for PML(flow-chart)
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Fingolimod
- MoA
- Adverse Effects - not dose dependent (6)
- Adverse Effects - dose dependent (3)
- sphingosine 1-phosphate receptor modulator
- impedes egress of lymphocytes from lymph nodes (particularyl during recirculation)
- Adverse Effeccts
- Bradycardia (usually transient but possibly fatal)
- diarrhea
- back pain
- elevation of liver enzymes
- cough
- chest pain
- Adverse effects (at high doses)
- seizure
- headache
- lymphopenia
Teriflunomide:
- Mechanism of action
- Adverse Effects
- Inhibits pyrimidine synthesis (arrests proliferation of activated lymphocytes)
- Adverse effects
- Alopecia
- Elevated ALT
- Back pain
- nausea
- nasopharyngitis
- Leukocytosis (unclear significance)
- Pregancny category X
Dimethyl Fumarate
- Mechanism of Action
- Adverse Effects
- Unknown, proposed:
- Affects Krebs cycle
- upregulation of anti-inflammatory cytokines
- cytoprotective effect
- Adverse Effects
- Flushing
- GI upset
- Lymphopenia
Mitoxantrone
- MoA
- Adverse effects (7)
- Topoisomerase inhibitor (inhibits DNA synthesis)
- Only FDA approved med for primary progressive MS
- Adverse Effects
- Nausea
- Hair loss
- Hypotension
- Rashes
- Urinary tract infection
- Menstrual disorder
- CARDIOTOXICITY - requires close observation
Risk factors (5) and triggers (2) for multiple sclerosis
Risk factors
- Northern lattitude environmental exposure before age 15
- Vitamin D deficiency
- Caucasian population
- Females (2:1 M:F)
- family history of MS (5-10x)
- Identical twins = 25% chance
Triggers
- Viral exposures
- EBV (90-95% of MS patients are EBV positive)
- canine distemper virus
- faroe island
2.
Genes that can increase your risk for MS (3)
HLA-DR2
IL-2R
IL7Ralpha
Test to order in Teenage girl with eye pain worsening with movement and lack of color vision
MRI with Fat-suppression of orbits (for Optic neuritis)
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Spinal cord symptoms that should raise suspicion for MS (6+1)
- L’hermitte’s sign” (barber’s chair phenomenon)
- Numbness / sensory level
- “GBS” like presentation with genitourinary signs (incontinence, urgency, erectile dysfunction)
- progressive, asymmetric paraplegia
- Deafferentated hand
- partial myelopathy
if patient is numb from neckline to navel, it’s SC lesion until proven otherwise
Charactersistic MS lesions of spine
Small
love to hug up against periphery
love the dorsal column
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MRI shows this lesion:
Risk of MS with:
No CNS lesions
1+ CNS lesion
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No CNS lesions: 25%
1+ CNS lesions: 72%
Treatment options for clearly evident primary progressive MS
(trick question)
Nothing: AAN
- interferon-beta and glatieramir do not prevent development of permanent disability n progressive forms of MS
- These medicaiton sincrease costs and have frequent side effects that may adversely affect quality of life
MRI lesions suggestive of MS
(picture)
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What are these suggestive of?
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Multiple Sclerosis
MRI buzzwords to suggest MS (5)
- Corpus callosum lesion
- Optic radiation lesion
- Brainstem lesion abutting 4th ventricle
- incomplete / partial enhancement
- T1 “black holes”
Known MS patient has Oligoclonal bands on CSF
what does this tell you?
Higher rate of relapse
Diseases which can show oligoclonal bands other than MS
(10)
- Viral infections (HIV/SSPE)
- NMO
- SLE
- ADEM
- Vasculitis
- Adrenaleukodystrophy
- Syphillis
- Lyme
- CADASIL (+/-)
- Sarcoid (+/-)
If Transverse myelitis patient fails to respond after course of high-dose steroids, what should you consider for acute treatment?
PLEX
“may be considered in pateints with TM who fail to improve after corticosteroids)
Pre-treatment studies for Fingolimod
Surveilance studies for Fingolimod
(2)
Precautions for fingolimod
(2)
(5)
CBC (due to lymphopenia)
VZV titer (due to immunosuppression)
LFT (due to risk of transamitis)
EKG (due to 1st dose bradycardia / conduction block)
ophtho exam (due to risk of macular edema)
Ophthomalogic exam every 3-4 months (more if DM or uveitits)
LFTs
6 hour observation after first dose (for conduction block)
avoid live viruses (immunosuppression)
Fingolimod
MoA (2) Adverse Effects (6)
MoA
- Sphingosine-1-phosphate moderator
- Prevents egress of immune cells into circulation
Adverse Effects
- 1st dose bradycardia / sinus block
- CI in patients with someheart diseases
- Decreased WBC
- Macular Edema
- Decreased PFTs
- Increased LFT’s
- Teratogen
Teriflunomide:
MoA (2)
Adverse Effects (4)
MoA
- Dihydroorotate dehydrogenase inhibitor
- Decreased immune cell replication
Adverse effects
- Immunosuppresssion (will need to ensure no TB)
- Hair loss
- hair loss
- Teratogen
Dimethyl Fumarate
MoA
(2)
Adverse effects
(3)
MoA
- immunomodulator, induces apoptosis and reduces expression of IL-4, IL-2, and TNF-alpha
- May also decreased adhesion molecules
Adverese Effects
- GI
- flushing
- Headaces
Mitoxantrone:
MoA
Adverse Effects
(2)
MoA
- Topoisomerase Inhibitor (inhibits DNA synthesis)
Adverese effects
- Systolic dysfunction
- Dose-dependent cardiotoxicity
- will need yearly cardiac function tests, even after finishing treatment
Big adverse effects you should worry about for Natalizumab (1) and relative risk (2)
PML!
After 24 doses and (+) JC virus: 1:200
After 24 doses and (+) JC virus, and prior immunosppressive treatment: 1:100
Pregnancy categories for MS drugs
- Glatiramer Acetate
- Interferons
- Fingolimod
- Natalizumab
- Mitoxantrone
- Teriflunomide
- Glatiramer: category B
- Interferons: Category C
- Fingolimod: Category C
- Natalizumab: Category C
- Mitoxantrone: Category D
- Teriflunamide: Category X
Patient with MS with personality changes comes in with this MRI
What medication is she likely taking?
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Natalizumab
(PML)
Optic neuritis / Transverse Myelitis in MS versus NMO
How are they different?
(4)
Compared to MS, NMO attacks are:
- More intense
- have more radicular signs
- More readicular symptoms
- (transverse myelitis) more likely to show longitudinally extensive lesions
Ab helpful in differentiating NMO from MS (1)
Sensitivity / specificity
How often is it present?
related prognostic note
Aquaporin-4 (anti-NMO)
Sensitivty: 73%
specificity: 90%
Present in:
38% with first-ever attack of Longitudinally extensive lesion
55% of these will have a relaps wof either TM or ON during the next year
Diagnostic criteria for NMO
(5)
- Optic neuritis
- Transverse Myelitis
- 2 of the following 3
- MRI lesion not suggestive of MS
- Longitudinally extensive transverse myelitis (3+ spinal vertebral segments)
- (+) NMO serology
Treatment for NMO
Acute (1+2)
Chronic (2)
- Steroids, Plasmapharesis if doesn’t respond
- Better response if:
- optic neuritis (opposed to TM)
- Onset of treatment <20 days from symptoms
- Better response if:
- Chronic
- Azathioprine + steroids
- Rituximab
ADEM
Typical population
Features (5)
Usually in young childrens / adolescences (peak age 3-10 years)
Features
- typically 7-14 days after infection (very rarely after vaccine)
- Headache / Vomiting
- Meningisumus
- Altered mental status
- multifocal neurologic signs
- ataxia
- tremors
- dysarthria
- hemiparesis, etc
- seizures (10-30%)
Child comes in with altered metnal status and multifocal neurologic findings following illness.
This is his MRI
How do you treat?
what is his prognosis?
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Acute disseminated encephalomyelitis (ADEM)
- Treatment
- Steroids (high-dose IV methylprednisolone) for 3-5 days
- afterwards oral prednisolone tapered over 4-6 weeks
- Prognosis
- long-term follow up is good
- many fully recover by 1-6 months
Patient comes in with ataxia, interstitial keratitis, and hearing loss:
What is your highest item on differential?
what should you exclude (2)?
what should you look for (2)
how do you treat (2)?
likely diagnosis: Cogan syndrome
Rule out:
syphillis
Sarcoid
Look for:
vascular diseases
(vasculitis, especially aortic insufficiency)
Treatment:
keratitis: topical steroids / atropine
hearing loss: oral steroids
Features of Neurosarcoidosis
Clinical (4)
CSF (1)
MRI (3)
Clinical
- multiple cranial nerves affected
- MC facial palsy (VII), occulomotor palsy (III, IV)
- hearing loss
CSF
- “asceptic meningitis” (elevated WBC and protein)
MRI
- give-away = non-caseating granulomas
- diffuse minengial enchancement
- possibly hydrocephalus
man comes in with oral / genital ulcers and anterior uveitis
What is his most likely race?
What test should you order and what should it show?
Behcet disease
- Typically japanese ar mediterranean men
- MRI features
- restricted diffuseion in:
- Brainstem
- diencephalon
- basal ganglia
- restricted diffuseion in:
Young adult comes in with “ADEM” like picture
What similarly presenting but potentially fatal condition should you rule out?
How?
If present, how do you treat it?
Acute hemorrhagic leukoencephalitis
- MRI Shows
- Asymemtric, large, edematous white matter lesion
- Punctate hemorrhages
- Treatment
- steroids
- PLEX
- IVIG
Alemtuzumab
What does it target?
why is it not commonly used?
Targets CD52 cells
due to adverse effects:
mainly that it can produce secondary autoimmune disorders (currently approved only for those who failed 2+ disorders)
Tremor most commonly seen in MS
Intention tremor
Patient with MS drug presents with seizure
What med is likely to blame?
What is the mechanism of action?
What is it used for?
What could increase their risk?
Dalfampridine
increases walking speeds in MS patients
Thought to work by facilitating conduction of action potentials via potassium channel blockade
Increases with renal impairment.
Risk of MS in patient’s with Clinically isolated syndrome (CIS)
30%
Alemtuzumab
Mechanism of action
Adverse effects
MOA: monoclonal antibody to CD52
Adverse effects (Cancer, cancer, cancer, kidney, clotting, and…can you stop the infusion because there’s a reaction)
- Melanoma
- thyroid malignancies
- blood malignancies
- thrombocytopenia
- anti-GBM disease
- life-threatening infusion reactions
Drug used to treat pendular nystagmus
Memantine
MS drug to avoid in:
Depression
Heart block
Heart Failure
+ JC virus Ab
Beta Blockers
Liver disease
Pregnancy
Depression: Interferons
Heart block: Fingolimod
Heart Failure: Mitoxantrone
+ JCV: natalizumab
Beta Blocker: Fingolimod
Liver disease: Fingolimod, Interferon, teriflunomide
Pregnancy: everything but Copaxone,
Patient presents with PML
Test to suggest related to MS therapy
MRI is of cerebellar peduncles is enhancing (in about 50% of patients)
Dissemination-in-space criteria for MS (4)
- Periventricular
- juxtacortical/cortical
- infratentorial
- Spinal cord
Need 2 of 4
Antibody associated with miller-fisher varient of GBS
GQ1b