Myasthenia Gravis
Also written as MG.
Ptosis IS associated with myasthenia gravis — the exam statement saying it's not is false
Myasthenia Gravis
- An autoimmune disorder where antibodies block or destroy acetylcholine receptors at the neuromuscular junction, leading to a disruption in communication between nerves and muscles.
- Protein Affected : Acetylcholine receptors (AchR)
- Symptoms : Muscle weakness, ptosis , double vision , and difficulty speaking or swallowing.
Read this in Genetic and Autoimmune Causes with Focus on Affected Proteins
Myasthenia Gravis (MG)
- Prevalence 150–200/million; bimodal distribution (young F M; older M F)
Read this in Pathology of Demyelinating Diseases: MS, NMO, ADEM, CPM
What our notes say
- Ptosis IS associated with myasthenia gravis — the exam statement saying it's not is false (High-Yield Clinical Exam Notes: Cranial Nerves, Respiratory, Cardio)
- Fluoroquinolones inhibit DNA gyrase and topoisomerase IV and are contraindicated in children, pregnant women, and patients with myasthenia gravis due to tendinopathy and cartilage toxicity. (Pharmco Notes)
- Neuromuscul Myasthenia gravis, neuropathies, muscular ar dystrophies, Gullain-Barre syndrome (GBS) (Examination of Respiratory system — Past Paper Questions & Answers)
- Many myasthenia gravis patients have either a thymoma or thymic hyperplasia. (Immunopathology complete mcqs — Past Paper Questions & Answers)
- Myasthenia gravis vs Lambert-Eaton — opposite mechanisms (Bone & Soft Tissue Tumour Pathology: Must-Know Diagnoses)
- Myasthenia gravis: antibodies attack acetylcholine receptors AFTER the nerve-muscle junction (postsynaptic); weakness gets WORSE with repeated muscle use (Bone & Soft Tissue Tumour Pathology: Must-Know Diagnoses)
Study material on Myasthenia Gravis
Practice questions on Myasthenia Gravis
Mr. Otieno has been diagnosed with myasthenia gravis. You are considering treatment with pyridostigmine and neostigmine. Which adverse effect is associated with these two drugs?
- Bronchoconstriction
- Irreversible action
- Constipation
- Diarrhea
- Reduced gastric secretions
Answer: D. Pyridostigmine and neostigmine are acetylcholinesterase inhibitors that increase acetylcholine levels at all cholinergic sites, including the GI tract. This leads to increased GI motility and secretions, causing diarrhea. Other cholinergic effects include bronchoconstriction, increased secretions, and bradycardia. --- ---
A person with myasthenia gravis notes increased muscle strength when he is treated with an acetylcholinesterase (AChE) inhibitor. The basis for his improvement is increased ---
- Amount of acetylcholine (ACh) released from motor nerves
- Levels of ACh at the muscle end plates
- Number of ACh receptors on the muscle end plates
- Amount of norepinephrine released from motor nerves
- Synthesis of norepinephrine in motor nerves
Answer: A.