Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

1. Rheum RC > Myositis > Flashcards

Myositis Flashcards

1
Q

Myositis classification

A

Adult onset DM: DM, Amyotrophic DM
Adult onset PM
Overlap myositis: ASA, Myositis assoc’d w/ CTD
Immune mediated necrotizing
IBM
Juvenile onset
Other: focal, giant cell, assoc’d w/ eosinophilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

**PM/DM diagnostic criteria **

A

Weakness
- Proximal painless weakness (no ocular/facial),
- Neck flexor weaker than extensor
- Pharyngeal (dysphonia),
- Upper esophageal (dysphagia)

  • Characteristic rash (Heliotrope, Gotton’s)
  • Elevated CK, aldolase, myoglobin, AST, ALT, LDH
  • MSAs/MAAs: Jo1
  • Abnormal EMG
  • Muscle biopsy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

DM rash biopsy*

A

Interface dermatitis with mucin (similar to SLE)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

** IIM EMG**

A
  1. Increased insertional activity w/ SPONTANEOUS FIBRILLATION and complex repetitive discharge
  2. LOW AMPLITUDE and SHORT DURATION POLYPHASIC motor unit action potential. EARLY RECRUITMENT
  3. Positive SHARP waves (initial down spike then wide up wave)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

** DM Derm Manifestations & where **

A

Heliotrope (eyelid, malar, forehead, nasolabial)
-V sign (chest/neck)
-Shawl sign (shoulders, prox arms)
-Holster sign (lat thigh)
-Gottrons (dorsal MCP/IP, extensor wrist elbow, knee)
- Mechanic’s hands - thickened crackened skin on dorsal/ventral surfaces of hands

-Nailfold: periungal erythema, cuticular overgrowth, dilated capillary loops
-Photosensitivity

-Subcutaneous calcification (JDM)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

DM mimics

A

Trichinosis
-Allergic contact dermatitis
-Drug reactions (hydroxyurea, pencillamine, diclofenac, anti TNF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Biopsy tips to max yield

A

MRI to direct

-Biopsy weak muscle opposite to that of EMG

-Do not biopsy muscle within 2-4weeks of EMG or within 3 mo of rhabdo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Adult onset DM clinical features

A

Rash (NO mechanic hands)
-Muscle disease (20% amyotrophic)
-MSA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

** DM muscle biopsy pathology **

A

COMPLEMENT mediated (vs T cell mediated in PM): C5b-9 MAC found on cells

-Perimysial and/or PERIVASCULAR inflamm (VASCULATURE = primary target vs endomysial myocyte in PM)

-PERIFASCICULAR ATROPHY of muscle fibers

  • Endomysial infiltration of mononuclear cells but NOT INVADING myofibers
  • B cells, pDC, and CD4+ NOT CD8 like in PM
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

DM MSA’s and characteristics*

A

Mi-2 - rash, periungal/cuticle growth, weakness. NO CANCER OR ILD, good prognosis. ANA+

-SAE - rash, myositis, DYSPHAGIA, ILD; CANCER

-MDA5 - ULCERATION (nailfold, over joints, oral), palmar papules, arthritis, fever, RAPID ILD, often AMYOPATHIC, ANA negative, NO CANCER

-Tif1Gamma - rash, low titre ANA, CANCER

-NXP2 - rash, fingertip ulcers, JDM,subcutaneous calcification, CANCER

-*all can have CADM except MI-2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Antisynthetase (ASA) characteristics

A
  • Proximal muscle weakness w/ elevated CK (5-10x ULN)
  • Raynauds
  • Mechanic’s hands (+/- Heliotrop/gottron)
  • ILD
  • Arthritis
  • Fever
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Antisynthetase (ASA) muscle pathology

A

Similarto DM but WITHOUT complement deposition

Perimysial pathology +/- perifasciular atrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Myositis assoc w/ CTD
-Which CTD and MAA

A

SSc: PM-SCl, RNP, Ku, U3RNP
-MCTD/SLE (RNP)
-Sjogrens (Ro)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

ASA MSA’s and assoc’d manifestations

A

*all have myositis and ILD

Jo1: rash, seroneg arthritis, Raynaud, fever, negative cancer association
-PL7: ILD> myositis, mechanic hand, arthritis, Raynaud, esophageal
-PL12: ILD > myositis, Raynaud, pHTN
-EJ: rash,
-OJ: rash, arthritis, fever

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Adult onset PM clinical features

A

Prox muscle weakness w/ elevated CK without other cause
-Cardiac (conduction, CHF)
-Increased cancer risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

** PM muscle histology **

A
  • Endomysial > perimysial inflammation (CD8+ T cells)
  • Endomysial infiltrates invade NON-NECROTIC fibers
  • MHC class 1 on sarcolemma
  • Vasculature SPARED
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

** Cancers assoc’d w/ DM/PM **

A

Adenocarcinoma:
- Breast, Ovary
- Lung
- GI: pancreas, stomach, colon,
- Taiwanese (nasopharyngeal and cervical)

-Hematologic: hematopoeitic cancer, and Hodgkin’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

** High risk for Cancer in IIM**

A

-Dermatomyositis
-TIF1γ
-NXP2
->40yo at IIM onset
-Persistent high dz activity despite tx (including relapse of previously controlled disease)
-Dysphagia (moderate to severe)
-Cutaneous necrosis or ulceration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Intermed Risk factors for Cancer in IIM

A

-Male sex
-IMNM: Anti-HMGCR
-PM: Anti-Mi2, SAE
-Anti-MDA5, CADM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Immune-mediated necrotizing myopathy (IMNM) clinical characteristics

A

-Myositis (prox weakness)
-MYALGIA
-HIGH CK 10-50xULN, rhabdo
-NO ILD/rash
-Rare assoc w cancer, HIV, ASA, another CTD
-Can be REFRACTORY to tx, bad prognosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

** Immune-mediated necrotizing myopathy (IMNM) muscle histology **

A

-Necrotic fibers
-Macrophage INVASION
-MINIMAL CD8+ T cells or lymphocyte infiltrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Immune-mediated necrotizing myopathy (IMNM) MSA and manifestations*

A

BOTH have severe myositis
NEITHER have ILD, rash

-SRP - PAIN (necrosis), myocarditis, dysphagia. ANA neg

-HMGCR (aka 200/100) - Statin exposure (lovastatin, simvastatin) or cancer or red yeast rice or oyster/shitake mushroom.
DRB1*11:01 HLA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

** IBM vs PM **
Demographic
Muscle involvement
Other organs
ANA
MSA
EMG
Response to therapy

A
  • MC IIM >50
  • SLOW onset
    -Proximal AND DISTAL muscle (Knee/foot extensor, finger flexor); Asymmetric
    -NO RASH, ILD, CANCER
    -Other organs: neuropathy (vs ILD, arthritis, cardiac in PM)
    -No MSA; sometimes ANA, C1NA
    -EMG: myopathic and neuropathic
    -POOR RESPONSE Tx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

** IBM muscle biopsy histology pathology**

A

Similar to PM
-CD8+ T cell infiltrate
- No perifascicular atrophy
- MHC class 1 expressed

Unique:
-Rimmed vacuoles
-Ragged red fibers
-Amyloid deposits
-Eosinophilic cytoplasmic inclusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

IIM DDx

A

Drug/Toxin: statin, interferon alpha, colchicine, amiodarone, antimalarias, AZT, alcohol, GC, cocaine, antifungal, anti TNF

-Neuromuscular: muscular dystrophy, NMJ d/o (MG, ELS), Denervating (ALS)

-Endocrine: hypo/hyperTSH, acromegaly, cushing, addison
-Infectious: bacterial (staph, strep, borrelia), viral (HIV, adenovirus, influenza), parasitic (toxo, trichinella, taenia)

-Metabolic: Glycogen storage, abN lipid metabolism, mitochondrial myopathy, nutritional d/o (vit D/E), electrolyte d/o (hypoCa/Ca/K/PO4)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

DM/PM Poor prognostic features

A

-Severe weakness
-Dysphagia
-Respiratory muscle involvement
-ILD
-Myocardial involvement
-Cancer
-MDA5
-Pathology: necrotizing myopathy

27
Q

** Myositis Tx - nonpharm and pharm **

A

Pred 1-1.5mg/kg (up to 80mg/d) divided dose until remission (normal CK and strength ~4-6wk) - taper 20% monthly until 20mg, then 5mg monthly until 10mg x3-6mo before taper

-MTX 25mg/wk
-AZA 2-3mg/kg/d
-MMF 1-1.5g BID (ILD/rash)
-LFN
-CYC only if severe (eg MDA5 ILD) and JDM w/ vasculitis

-Tacrolimus 0.1mg/kg/kd; 2-5mg BID if resistant T cell mediated PM and lung dz
-Cyclosporine 3-5mg/kg/d

-IVIG 2g/kg x5d → monthly 2g/kg over 3d for severe refractory DM (esp dysphagia and HMGCR)

-RItux - 1g d1 and d15 → 1g q6mo

-Repository corticotropin injection - 80USP units SC twice a week x3 mo

-Nonpharm:
-rehab - passive/active assisted x4-6 weeks until strength and inflamm improves
-Vaccines
-OP
-PJP

28
Q

** Steroid myopathy vs IIM exacerbation **

A

Steroid myopathy
- NO elevated CK/aldolase,
- NO MRI inflammation
- Acute (eg ICU) - prox + distal
- Chronic - proximal - pelvic > arms
- Biopsy - nonspecific atrophy of type 2b fibers WITHOUT inflamm infiltrate

29
Q

** Risk factors for statin myopathy**

A

Statin characteristics: higher dose, lovastatin/simvastatin > others
-Other drugs inhibiting CYP3A4
-Other neuromuscular d/o: eg ALS
-Hypothyroidism
-Hypovitamin D

30
Q

** 3 drugs which increase risk of statin myopathy**

A

CYP3A4 inhibitors: cyclosporin, macrolides, azole antifungals, HIV/HCV protease inhibitors
-Competitive CYP3A4 binders: colchicine with simvastatin.
-Drugs that also cause myopathy (gemfibrozil)

31
Q

** Nonpharm contributor to statin myopathy **

A

Grapefruit consumption
-Strenuous exercises
-Hypothyroidism
-Vitamin D def (myalgia)

32
Q

** FIVE elements that indicate a non-inflammatory cause in myopathies**

A

Muscle involvement: proximal AND distal, facial
-No inflammation: normal CK, ESR, CRP, no inflamm infiltate on bx
-Trigger: Exercise
-Not responding to steroids
-FamHx or early childhood
-EMG not showing myopathic

33
Q

** Statin MSK manifestations**

A

Myalgia
-Asymptomatic hyperCK (neg MRI)
-Myositis
-Rhabdo (CK, myoglobinuria, AKI)

34
Q

** 5 ways you can distinguish adult myotonic dystrophy from an inflammatory myositis**

A

Muscular dystrophy vs IIM
– Genetic vs Inflammatory
– Childhood (mostly) vs Adult (mostly)
– Proximal and distal vs Proximal
– Steroid response: none vs responsive
– Cardiomyopathy: Often vs not often
– AB: none vs myositis AB
– Biopsy: low/no dystrophin staining vs perimysial/perivascular inflamm
– Genetic testing for muscular dystrophy

35
Q

Myositis antibody, name specific clinical finding: Jo1

A

MC AB for Antisynthetase
-PM/DM w/ ILD

36
Q

Myositis antibody, name specific clinical finding: PL7

A

Antisynthetase
-PM/DM w/ ILD
ILD> myositis, mechanic hand, arthritis, Raynaud, esophageal

-OJ:

37
Q

Myositis antibody, name specific clinical finding: PL12

A

Antisynthetase
-ILD more often than Myositis (clinically amyopathic)
-Raynaud
-pHTN

38
Q

Myositis antibody, name specific clinical finding: EJ

A

Antisynthetase
-PM>DM w/ ILD

39
Q

Myositis antibody, name specific clinical finding: OJ

A

Antisynthetase
-PM/DM w/ ILD
-Fever

40
Q

Myositis antibody, name specific clinical finding: KS

A

Antisynthetase
-ILD more often than Myositis

41
Q

Myositis antibody, name specific clinical finding: Zo

A

Antisynthetase
-ILD with Myositis

42
Q

Myositis antibody, name specific clinical finding: Ha

A

Antisynthetase
-ILD with Myositis

43
Q

Myositis antibody, name specific clinical finding: Mi2

A

DM w/ rash > muscle symptoms
-NO cancer or ILD
-Good prognosis (tx RESPONSIVE)
- ANA+

44
Q

Myositis antibody, name specific clinical finding: MDA5

A
  • DM (gottron, helitrope, shawl, V, holster)
  • **Often AMYOPATHIC, CADM **
  • Palmar papules
  • Polyarthritis, fever,
  • Alopecia
  • ULCERATION (nailfold, over joints, oral),
  • Less cancer but possible
    -DM w/ rapidly progressive ILD
    -Pneumomediastinum
  • ANA negative,
45
Q

Myositis antibody, name specific clinical finding: Tif1G

A

-DM
-Classic DM Rash
-Low titre ANA
-MOST associated with cancer

46
Q

Myositis antibody, name specific clinical finding: NXP2

A

DM - classic rash, finger tip ulcer,
-Subcutaneous calcification
-Juvenile DM
-Cancer associated

47
Q

Myositis antibody, name specific clinical finding: SAE

A
  • DM + mild ILD
    -Cancer associated
    -Dysphagia
48
Q

Myositis antibody, name specific clinical finding: SRP

A

Severe, acute, resistant necrotizing myopathy

49
Q

Myositis antibody, name specific clinical finding: HMG COA reductase

A

Necrotizing myopathy related to statin use in majority

50
Q

DDX ILD with skin features, and NO muscles weakness

A
  • SLE
  • Sjogren’s
  • ANCA vasculitis (especially MPO+)
  • DM - MDA5/CADM
  • DM - SAE (ILD is rare however)
  • Antisynthetase syndrome (often have weakness)
  • IPAF (interstitial PNA w/ autoimmune features)
51
Q

** Causes of necrotizing myositis**

A
  • Anti-SRP, HMGCR necrotizing myopathy (+/- statin exposure)
  • Antisynthetase syndrome w/ necrotizing myopathy
  • Cancer associated myositis
  • Viral necrotizing myopathy: HIV, HCV
  • Overlap syndrome necrotizing myopathy (SSc features/antibodies)
52
Q

** Antisynthetase AB’s and their target**

A

Jo1
PL2/7
EJ/OJ
KS
Zo
Ha

**target against amino-acyl t-RNA synthetase
(eg Jo1 against cytoplasmic protein histidyl tRNA synthetase 1)

53
Q

** Treatment for resistant skin dz in IIM**

A

Aggressive sun protection
Topical
Antipruritic
Antimalaria

Aza, MMF, MTX
Dapsone, IVIG, RTX, CNI
Tofa

54
Q

** Causes of high CK **

A

Transient: exercise, trauma, seizure, psychosis

Cardiac: MI, arrhytmia, myocarditis

Neurogenic: radiculopathy, motor neuron disease (ALS), mononeuritis multiplex

Myopathic - acquired:
- Drugs (statin, EtOH, cocaine, chloroquine, colchicine, statins)
-Endocrine (hypo/hyperthyroid, hypoPTH, hypoK/PO4),
-IIM (PM, DM, IMNM)
- Infection: viral/fungal myositis

Myopathic - Inherited:
- Muscular / myotonic dystrophies,
- Metabolic myopathies

55
Q

**Drugs causing muscle disease or elevated CK

A
  • Antidepressants: TCA, venlafaxine, sertraline, escitalopram
  • Antipsychotics: Seroquel, haldol, clozapine, olanzapine
  • Antiretrovirals: tenofovir, abicavir, ralegravir
  • Antimalarials
  • Daptomycin
  • Lithium
  • Colchicine
  • Statin
56
Q

**Enzymes elevated in IIM
-Which is most sensitive vs specific **

A

-CK = most sensitive and specific
-Aldolase,
-Myoglobin,
- AST, ALT,
- LDH

57
Q

** Extramuscular & extraderm Sx of DM/PM**

A

Constitutional symptoms

MSK
- Arthralgias,
- Arthritis (20-70%); associated with antisynthetase syndrome

Pulmonary:
- ILD (70% of patients with antisynthetase antibodies);
- Aspiration pneumonia;
- Respiratory muscle weakness,
- pHTN

GI:
- Esophageal dysmotility (10-30%);
- Reflux due to lower esophageal sphincter weakness (15-50%);
- Rectal incontinence due to sphincter ani weakness;
- Intestinal perforation due to vasculitis (more juvenile)

Cardiac:
- Arrhythmias,
- Conduction blocks,
- Myocarditis

Vascular:
- Raynaud’s (20-40%)
- Vasculitis (juvenile DM),
- Skin ulcerations (juvenile),
- Livedo reticularis,

58
Q

Hyperthyroid vs Hypothyroid CK levels

A

Normal in Hyperthyroid
Elevated in Hypothyroid

59
Q

** Components of NORMAL EMG (vs in myopathy) **

A

Insertional/spontaneous activity:
-should not have spontaneous activity (vs variable fibrillation and sharp waves in myopathy)

Motor unit analysis (amplitude, duration, # of phases, firing pattern)
- Morphology normal (vs small amplitude, short duration, increased polyphasia)

Recruitment - number of recruitable motor units
- Normal (vs early recruitment)

60
Q

** Indications to order EMG **

A

Localize pathology of neuromuscular disorder: neurogenic vs myopathic, vs NMJ

Determine severity of suspected neuromuscular disorder

61
Q

** How to tell neurogenic vs myopathic conditions apart on EMG **

A

Myopathic: EARLY recruitment = large number of motor units but SMALL amplitude, POLYphasic >4phases in a wave

Neurogenic: REDUCED recruitment bc axon/neuron loss but LARGE amplitudes

62
Q

** How to differentiate demyelinating peripheral neuropathy and an axonal peripheral neuropathy by NCS and EMG **

A

NCS:
- Demyelinating: SLOWED conduction velocities with PRESERVED compound muscle action potential (CMAP)/sensory nerve action potential (SNAP) amplitudes
- Axonal neuropathies have REDUCED CMAP/SNAP amplitudes with PRESERVED conduction velocities.

EMG:
- Axonal neuropathies have EARLY denervation abnormalities
- Demyelinating neuropathies show denervation abnormalities LATER when axons are secondarily affected

63
Q

3 similarities and 3 differences between the pathology for DM/PM

A

3 differences:
- Complement in DM (vs T-cell mediated in PM)
- Infiltrate CD4 predominant and other cells like B-cells, dendritic cells (DM) vs CD8 predominant (PM)
- Perivascular infiltrate (DM) vs endomysial infiltrate (PM)
- Perifascicular atrophy (DM) vs invasion of non-necrotic fibres (PM)

3 similarities:
- Upregulation of MHC1;
- Muscle fibre necrosis;
- Evidence of degeneration and regeneration

1. Rheum RC (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions