Path- Myopathies Flashcards
Floppy baby syndrome and dead withing three years. Disease and mechanism
Werdnig- Hoffman Disease, type I spinal muscular atrophy, LMN lesion and absence of a stretch reflex
Two hallmarks of Werdnig- Hoffman Disease
Grouped atrophy and dead within 3 years
DMD has a ______ gene defect–> _________ deficiency
XP21, dystrophin
Differential diagnosis between DMD and BMD
Age (DMD-kids, BMD- adults) Dystrophin Levels (DMD- absent, BMD- decreased)
Three DMD histological features
Group atrophy
Increase in connective tissue
Regeneration (blue hue)
4 Adverse Effects of DMD
- Cardiac failure—progression to the heart muscle
- Cognitive impairment—mental retardation
- CK increase during 1st decade, then decreases as muscle mass decreases (needed for muscle energy)
- Death from respiratory failure (diaphragm)
Describe the spread of effects of DMD
Begins in pelvic girdle to extends to shoulder girdle
How to diagnose MMD via thenar muscles
percussion –> thumbs moves into opposition and adduction then slowly returns
Impaired muscle relaxation—can contract but can’t let go (hand shake)
MMD
Hallmark of congenital MMD
“tented” or inverted “V” shaped upper lip
3 histological features of MMD
Roughly homogenous fiber size
Centralized nucleus
Fibrosis and strips of nuclei in longitudinal section
Describe progression of Ethanol Myopathies
Rhabdomyolysis– ethanol is so high that it causes muscle breakdown, leads to decreased circulation of myoglobin, easily filtered into urine– myoglobinuria
Hallmark organ dysfunciton of MG
Thymus
3 Differences between MG and Lambert Eaton
Small cell carcinoma of the lung
• Small cell CA of lung (~60%)
DOES NOT improve with acetylcholinesterase
increased nerve conduction with repetitive stimulation in LE
