22 results
Autoimmune Myositis
Necrotizing myopathy is associated with higher CK levels, greater level of muscle weakness, less systemic
Autoimmune Myositis ... Necrotizing myopathy ... anti-synthetase syndrome ... and anti-HMGCR myopathy ... #Myositis #diagnosis
Idiopathic Inflammatory Myopathies (IIM's)

RASH + MUSCLE WEAKNESS → Consider idiopathic inflammatory myopathies (IIM's)

 • Overlap Myositis
Any inflammatory myopathy ... antisynthetase syndrome ... Inflammatory myopathy ... #IIMs #diagnosis ... #dermatology #Myopathy
Creatine Kinase - Causes of Elevated CK Levels
Acute CK Elevation (Pain > Weakness):
 • RHABDOMYOLYSIS
Critical Illness Myopathy ... - Inflammatory myopathy ... polymyositis, necrotizing myopathy ... - Autoimmune ... Inclusion body myositis
Myositis Specific Antibodies (MSAs)

Dermatomyositis: MDA5, TIF1y, NXP2, Mi-2, SAE
Anti-Synthetase Syndrome: Jo-1, PL7, PL12, EJ, OJ
Immune Mediated
Myositis Specific ... Anti-Synthetase Syndrome ... Mediated Necrotizing Myopathy ... MSAs #clinical #diagnosis ... #rheumatology #table
Weakness - Differential Diagnosis Framework

Approach To Weakness:
 • Non-neuromuscular disorder (Cardiac, pulmonary etc)
 • CNS ->
- Differential Diagnosis ... Lack of UMN/LMN signs ... proximal weakness Myopathy ... mediated necrotizing myopathy ... • Autoimmune:
Causes of Neuromuscular Weakness
 • Spinal Cord: Demyelinating Disease (MS), Epidural abscess, Infarction, Syringomyelia, Tetanus, Transverse
Causes of Neuromuscular ... Tetanus, Transverse Myelitis ... Motor Nerves: ALS ... Mitochondrial myopathy ... #differential #diagnosis
Important Causes of Diplopia 
TIER 1-CRITICAL
Basilar artery thrombosis, Botulism, Basilar meningitis, Aneurysmn
TIER 2-EMERGENT:
Vertebral dissection, Myasthenia gravis,
Important Causes ... , Orbital apex syndrome ... sclerosis, Thyroid myopathy ... neuropathy, Orbital myositis ... #differential #diagnosis
Systemic Lupus Erythematosus (SLE): Musculoskeletal Manifestations

 • Immune Complex Deposition
    - Arthralgia, Arthritis
Normal CK - Myositis ... femoral heads • Myopathy ... (Also caused by ... pathophysiology #signs ... #symptoms #diagnosis
Generalized Weakness - Differential Diagnosis Framework
"l feel weak":
 • Infectious: Influenza, EBV, PNA, Bacteremia, Sepsis
 •
- Differential Diagnosis ... I am weak": • Myopathy ... Polyneuropathy, ALS ... Inflammatory/Rheum: Myositis ... #causes #neurology
Inflammatory Myopathies
Dermatomyositis
 • Onset: Subacute
 • Pattern: Proximal
 • CK: Up to 50X ULN
 • Autoantibodies:
Inflammatory Myopathies ... heliotrope, shawl sign ... exclusion Necrotizing Autoimmune ... Myositis • Onset ... #rheumatology #table