Skeletal Pathology Flashcards
Carnitine palmityl transferase def.
cannot metabolize long chain fatty acids. Muscular pain after exercising with myoglobinuria. Biopsy normal
Carnitine def
carnitine transfers long chain fatty acids into mitochondria. Proximal muscle weakness and atrophy, denervation and peripheral neuropathy. Biopsy - accumulation of lipid in sarcoplasm outside mito
Ragged red fibers
mitochondrial diseases - accumulation of mitochondria. often def in cytochrome oxidase
Werdnig-Hoffman
spinal muscular atrophy. infants show progressive weakness and don’t live beyond 1 year.
Pompe disease
inherited glycogen storage disease. severe form. severe hypotonia and areflexia. affects skeletal and cardiac muscle, CNS and liver.
Mcardle dx
inherited glycogen storage disease. more common and less severe. cramping during exercise, cannot make lactate. tx. avoid vigorous exercise. biopsy –> non membrane bound glycogen (pompe is membrane bound glycogen)
Myotonic Dystrophy
most common adult form of muscular dystrophy. autosomal dom. via expansion of trinucleotide repeats. slow muscle relaxation and progressive weakness and wasting. ATROPHY OF TYPE I AND HYPERTROPY OF TYPE II. assoc with DM. may also see cataracts, testicular atrophy, cardic issues.
Central core disease
Ryanodine receptor issue. Causes malignant hyperthermia from succinylcholine.
Dermatomyositis
heliotrope rash, macular rash, grotton’s papules. all ages. high serum CK. autoimmune. IgG and IgM microagiopathy. Immune complexes deposit in walls and cause ischemic injury of individual fibers– perifasicular atrophy and perimysial inflammation (outtermost layer of muscle bundle). acquired disorder w/ symm proximal weakness and non supp inflamm.
Polymyositis
Cytotoxic t-cell mediated autoimmunity. Anti Jo. endomysial inflammation w/ necrotic muscle fibers. acquired disorder w/ symm proximal weakness and non supp inflamm.
Inclusion body myositis
like polymyositis w/ granular material in vacuoles (rimmed vacuoles). b amyloid. acquired disorder w/ symm proximal weakness and non supp inflamm.
Myasthenia Gravis
autoantibodies against post-synaptic Ach receptor. muscle weakness that worsens with use and improves with rest. Associated with THYMIC issues. improves with AchE inhibitors
Lambert-Eaton Syndrome
paraneoplastic syndrome. antibodies against presynaptic ca+ channels. muscle weakness and fatigability which improves with use. Eyes usually spared.
side effect of corticosteroids
atrophy of type II muscle fibers (fast twitch)
Schwannoma vs. Neurobromas
Sch – pushes nerve to side and is well circumscribed. usually CN VII unilaterally.
NF - grow within nerve and within perineural sheath
