Sandbox Myopathy

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Differentiating Various Muscle Weakness

	Symptoms								History	Physical Examination	Diagnosis
	Age of onset	Muscle weakness		Fatigue	Muscle pain	Neuropathy	Myoglobinuria	Other features			Laboratory Findings		Creatine Kinase	Muscle Biopsy	Electromyogram
		Proximal	DIstal
Medications
Corticosteroids	Variable	+	-	-	+	-	-	Central obesity Excessive sweating Insomnia Reduced libido  Amenorrhea Infertility  Psychological disturbances	+ History of medications	Facial and sphincter muscles usually are spared	+ ACTH Stimulation test
Statins	60+	+	-	-	+	-	-/+(rhabdomyolysis)		Positive medication history	Tenderness Muscle aches			↑↑	Necrosis Degeneration, and regeneration of fibers Phagocytic infiltration	-
Anti-Thyroid
Chemotherapeutic
Organophosphate intoxication
Alcohol	Variable	+								Change in mental status Telangiectasia Peripheral neuropathy
Endocrine
Cushing's disease
Adrenal insufficiency
Secondary hyperparathyroidism
Hyperthyroidism
Hypothyroidism
Inflammatory / Rheumatologic
Dermatomyositis
Polymyositis
Inclusion body myositis
Fibomyalgia
Polymyalgia Rheumatica
Chronic Pain Syndrome
Genetic
Becker muscular dystrophy
Limb-girdle muscular dystrophies
Myotonic dystrophy type 1
Infectious
Lyme disease
Infulenza
Polio
Syphilis
HIV
Neurologic
ALS
Stroke
GBS
Multiple Sclerosis
Neuro-muscular
Botulisim
Lambert-Eaton myaes
Myasthenia gravis
Paraneoplastic
Metabolic
Glycogen storage disease
Lipid storage disease
Mitochondrial