Disease Summary - Sheet1 Flashcards
Malignant hyperpyrexia (malignant hyperthermia)
Caused by mutation in gene for VG Ca2+ ion channel.
Mutation causes uncontrolled release of calcium from SM cells. Triggered by inhalational anesthetics.
Treat by blocking Ca++ induced Ca++ release: Dantrolene.
Amyotrophic lateral sclerosis
Spinal chord lesion, maybe caused by defect in superoxide dismutase.
Lambert Eaton Syndrome
AI neuromuscular junction disease causing autoantibodies to presynaptic Ca++ channels causing a decrease in ACh release. uncommon.
Muscle weakness improves with use.
Commonly known as Lou Gehrig’s disease. Stephen Hawking is a well-known patient who highlights the lack of cognitive deficit.
Botulism
Botulinum is from bad bottles of food and honey (causes a flaccid paralysis, honey = floppy baby syndrome).
Myasthenia gravis
AI disease which results in destruction of nicotinic receptors on skeletal muscle.
Treat with something prolonging ACh release–anticholinesterases– (augment muscle contraction):
Neostigmine, Pyridostigmine, Edrophonium (short acting/diagnostic).
Muscular dystrophy
Duchenne’s: X-linked frameshift mutation –> deletion of dystrophin gene.
Becker’s: X-linked mutated dystrophin gene. Less severe than Duchenne’s.
Diagnose muscular dystrophies by increased CPK and muscle biopsy.
Muscle spasms, cosmetic
Treat w/ something blocking ACh release: Botulinum toxin.
Surgical paralysis
Block nicotinic receptors (blocks muscle depolarization and contraction): d-tubocurarine or Mivacurium)
What is the most common cause of septic arthritis in sexually active people?
Neisseria gonorrhoeae
spinal muscular dystrophy
autosomal recessive motor neuron diseases that present in childhood or adolescence.
All forms associated with motor neuron 1 (SMN1) mutations.
The most common form of SMA is known as Werdnig-Hoffmann disease.
myotonic dystrophy
autosomal dominant disorder, with increased CTG trinucleotide repeat sequences on chromosome 19 (trinucelotide repeat disorder), which affects the mRNA for dystrophia myotonia protein kinase (DMPK).
Dermatomyositis
inflammatory disorder of skeletal muscle and skin.
Involves malar rash (similar to SLE), Gottron’s papules, and heliotrope rash (violaceous discolored rash of upper eyelids associated with periorbital edema), accompanied by scaling erythematous eruption or dusky red patches over the knuckles, elbows, and knees.
Polymyositis
No skin involvement, but similar otherwise to Dermatomyositis.
Progressive symmetric proximal muscle weakness, characterized by endomysial inflammation with CD8+ T cells.
Most often involves shoulders.
Pathogenesis: T-cell mediated injury of myocytes
Inclusion body myositis
Begins with the involvement of distal muscles, in contrast to dermatomyositis and polymyositis. No beneficial effect with immunosuppressive agents in contrast to Dermo– and Poly–.
What are the causes of elevated creatine kinase?
MI–diagnose with CK-MB isoenzyme and troponin I.
Skeletal muscle diseases–muscular dystrophies or muscle trauma.
