Flashcards in Muscle Deck (96)
Enzyme activities to assess muscle damage
Creatine kinase (CK)
Aspartate aminotransferase (AST)
Lactate dehydrogenase (LDH)
What is Serum CK a sensitive indicator for?
myonecrosis in both skeletal and heart muscle
When does Serum CK activity increase?
Increased within hours of a muscle insult and peaks within 4-6 hours after injury
When can CK elevate?
What enzyme has high activity in skeletal and cardiac muscle as well as Liver, RBCs, and other tissues?
When is the peak time for AST levels after an insult?
What do elevations in CK and AST reflect?
recent or active myonecrosis
What do elevations of CK reflect?
myonecrosis is likely going on
What do elevated AST and decreasing or normal CK levels indicate?
Myonecrosis not continuing
Elevations in LDH specify what?
What tests assess concurrent renal disease?
Urine specific gravity
White blood cell count
Red Blood cell count
Evaluation of cast formation
What does a positive Hemastix test in the absence of hemolysis or RBCs in urine indicate?
Exercise Challenge test
15 mins of slow trot with CK activity sampled before and 4-6 hours after
What do elevations of greater than 5-fold CK indicate?
to detect spontaneous or evoked potentials of neurogenic or myogenic
What do horses with abnormalities show on electromyography?
Spontaneous electrical activity
Fibrillation potentials: spontaneous firing of muscle fibers
Positive sharp waves
Myotonic discharges: bursts of complex high-frequency potentials
Complex repetitive discharges
What are EMG and NCVs used to classify?
classify the disease Neuropathic or Myopathic
Use of Nuclear Scintigraphy
ID some forms of muscle damage
area of deep muscle damage
How does Nuclear Scintigraphy work?
Technetium 99 m methylene diphosphonate is taken up in inflamed and damaged muscle
How is muscle fiber disruption seen on Ultrasonography?
hypoechoic area with loss of the normal fiber striation
How do es a defect in muscle/hematoma appear on ultrasonography?
How does increased connective tissue or loss of muscle appear on ultrasonography?
How does mineralization or gas pockets appear on ultrasonography?
Hyperechoic shadowing artifacts
suprascapular nerve is damaged and muscle over the scapula are atrophied
How long does it take for denervation to result in 50% muscle mass loss?
2 - 3 week period
What are the causes of Atrophy?
Malnutrition and cachexia
Hyperkalemic Periodic Paralysis
What causes HYPP?
inherited defect in the skeletal muscle sodium channel
What type of trait is HYPP?