Myasthenia Gravis：重症肌无力.ppt

* * * * * * * * * * * * * * * * * * * * * * * * Myasthenia Gravis Mike Willcut Myasthenia What? My-as-thee-nee-ah Grr-a-vis Auto immune disease Hereditary genetic mutation Causes muscle weakness Where have I heard that? Contraindication for Versed Fentanyl Precaution for sux Pathophysiology Auto Immune Antibodies attack Ach Receptors Decreased cell excitement Electrical threshold No action potential Weakness Cell with MG This might be on the Quiz How does MG affect the body? A – Blocks motor receptors causing weakness B - Increases stimulus threshold C - Decreases stimulus threshold D - Reduces amount of Ach released causing weakness Classification 1: Eye muscle weakness (EMW) 2: EMW and other mild muscle weakness Predominantly limb or axial muscles Predominantly bulbar or respiratory muscles 3: EMW and other moderate weakness Predominantly limb or axial muscles Predominantly bulbar or respiratory muscles 4: EMW and other severe weakness Predominantly limb or axial muscles Predominantly bulbar or respiratory muscles 5: Intubation needed to maintain airway Who’s at Risk Females 20-40 Males 60-80 Those with another AI Disease Penicillamine users (rheumatoid med) Enlarged Thymus or thymoma 20 in 100,000 or 2 in 1million (discrepancy) Diseases Typically Associated With MG Diabetes Type 1 Rheumatoid Arthritis Lupus Demyelination CNS Disease Other Auto immune diseases What will we see? Hallmark S/S Eye lid drooping (ptosis) Impaired speech (dysarthria) Difficulty Swallowing (dysphagia) Double Vision (dipoplia) Easily fatigued, quick recovery with rest Waddling gait Physical Exam Test for muscle fatigueability Look up and to the side for 30 sec If supine, look at feet for 1min Arms stretched forward for 1min 10 deep knee bends or squats Look for ptosis and ask about diplopia Myasthenia Crisis Requires immediate assistance Shortness of breath Extreme muscle weakness General fatigueablility Respiratory muscle paralysis MG in Pregnancy Many mothers get worse 1