10.3 Treatments and Nutrition
3 min read•june 18, 2024
Myasthenia gravis is an autoimmune disorder that messes with your muscles. It attacks the connection between nerves and muscles, making it hard for your brain to tell your body to move. This can lead to weakness and fatigue in various muscle groups.
The disease causes a range of symptoms, from droopy eyelids to trouble breathing. It's diagnosed through blood tests, nerve stimulation, and muscle activity measurements. Understanding how it works helps explain why rest can improve symptoms and why certain treatments are effective.
Overview of Myasthenia Gravis
Mechanism of myasthenia gravis
Top images from around the web for Mechanism of myasthenia gravis
Frontiers | Autoimmune Pathology in Myasthenia Gravis Disease Subtypes Is Governed by Divergent ... View original
Is this image relevant?
Frontiers | Autoimmune Pathology in Myasthenia Gravis Disease Subtypes Is Governed by Divergent ... View original
Is this image relevant?
Frontiers | Myasthenia Gravis: Autoantibody Specificities and Their Role in MG Management View original
Is this image relevant?
Frontiers | Autoimmune Pathology in Myasthenia Gravis Disease Subtypes Is Governed by Divergent ... View original
Is this image relevant?
Frontiers | Autoimmune Pathology in Myasthenia Gravis Disease Subtypes Is Governed by Divergent ... View original
Is this image relevant?
1 of 3
Top images from around the web for Mechanism of myasthenia gravis
Frontiers | Autoimmune Pathology in Myasthenia Gravis Disease Subtypes Is Governed by Divergent ... View original
Is this image relevant?
Frontiers | Autoimmune Pathology in Myasthenia Gravis Disease Subtypes Is Governed by Divergent ... View original
Is this image relevant?
Frontiers | Myasthenia Gravis: Autoantibody Specificities and Their Role in MG Management View original
Is this image relevant?
Frontiers | Autoimmune Pathology in Myasthenia Gravis Disease Subtypes Is Governed by Divergent ... View original
Is this image relevant?
Frontiers | Autoimmune Pathology in Myasthenia Gravis Disease Subtypes Is Governed by Divergent ... View original
Is this image relevant?
1 of 3
- Autoimmune disorder targeting the neuromuscular junction
- Antibodies attack and destroy acetylcholine receptors (AChRs) on the postsynaptic membrane of the neuromuscular junction reducing the number of functional AChRs
- Impaired neuromuscular transmission results from decreased sensitivity to acetylcholine (ACh) released by the presynaptic nerve terminal
- Reduced ability of ACh to bind to AChRs and generate action potentials in the muscle fiber
- Muscle weakness and fatigue occur due to insufficient muscle fiber activation from impaired neuromuscular transmission
- Muscles require stronger and more frequent nerve impulses to contract effectively
- Weakness worsens with repetitive muscle use (typing) and improves with rest
- Primarily affects skeletal muscles, which are responsible for voluntary movement
Symptoms of myasthenia gravis
- Ocular symptoms manifest as diplopia (double vision) and ptosis (drooping eyelids)
- Bulbar symptoms include
- Dysarthria (slurred or nasal speech)
- Dysphagia (difficulty swallowing)
- Facial muscle weakness
- Limb weakness affects proximal muscle groups more than distal causing fatigue with repetitive movements
- Difficulty climbing stairs, lifting objects, or raising arms above the head
- Respiratory muscle weakness leads to
- Dyspnea (shortness of breath)
- Orthopnea (breathing difficulty when lying flat)
- Fluctuating nature of symptoms where weakness worsens with activity (chewing) and improves with rest
Causes and diagnosis of myasthenia gravis
- Causes
- Autoimmune disorder (most common)
- Exact trigger unknown but genetic predisposition and environmental factors may play a role
- Thymoma (tumor of the thymus gland) present in 10-15% of patients may trigger autoimmune response
- Autoimmune disorder (most common)
- Diagnostic tests
- Acetylcholine receptor antibody test detects presence of antibodies against AChRs in the blood
- Positive in 80-90% of patients with generalized myasthenia gravis
- Edrophonium (Tensilon) test uses a short-acting acetylcholinesterase inhibitor administered intravenously to temporarily increase ACh levels at the neuromuscular junction
- Positive test shows brief improvement in muscle strength
- Electromyography (EMG) with repetitive nerve stimulation measures electrical activity in muscles during nerve stimulation
- Decremental response in muscle action potential with repetitive stimulation suggests myasthenia gravis
- Single-fiber EMG is a highly sensitive test for detecting impaired neuromuscular transmission
- Abnormal jitter and blocking of muscle fiber action potentials occur in myasthenia gravis
- Acetylcholine receptor antibody test detects presence of antibodies against AChRs in the blood
Autoimmune and Neurotransmitter Aspects
- Myasthenia gravis is one of several autoimmune diseases where the immune system mistakenly attacks the body's own tissues
- The disease affects the transmission of neurotransmitters (specifically acetylcholine) at the neuromuscular junction
- The thymus gland, which plays a crucial role in the immune system, may be involved in the production of antibodies that attack AChRs
Key Terms to Review (38)
$Fe^{2+}$: $Fe^{2+}$ is the chemical symbol for the ferrous ion, which is the divalent form of the iron (Fe) element. This ion is an important component in various biological processes and plays a crucial role in the context of treatments and nutrition.
$Fe^{2+}$ is the reduced form of iron, meaning it has a charge of 2+ and is involved in numerous redox reactions within the body. It is essential for the proper functioning of the human body, particularly in the transport and storage of oxygen, the production of energy, and the maintenance of a healthy immune system.
$Fe^{3+}$: $Fe^{3+}$ is the ferric ion, a positively charged iron ion with a charge of +3. It is an important component in various biological processes and medical treatments related to nutrition and health.
Anemia: Anemia is a condition characterized by a reduced number or impaired function of red blood cells, leading to a decrease in the oxygen-carrying capacity of the blood. This can have significant implications for an individual's overall health and wellness, particularly in the context of nursing practice and the management of various medical conditions.
Anticoagulants: Anticoagulants are medications that help prevent the formation of blood clots by interfering with the normal clotting process. They are commonly used to treat and prevent conditions like deep vein thrombosis, pulmonary embolism, and atrial fibrillation, where there is an increased risk of clot formation.
Bone Marrow: Bone marrow is the soft, spongy tissue found inside the hollow cavities of bones. It is responsible for the production of various blood cells, including red blood cells, white blood cells, and platelets, which are essential for hematological wellness across the lifespan and can be impacted by nutritional strategies and treatments.
Coagulation Cascade: The coagulation cascade is a complex series of enzymatic reactions that lead to the formation of a fibrin clot, which helps stop bleeding and promote wound healing. This process is crucial in the context of treatments and nutrition, as it can be affected by various factors and interventions.
Deferasirox: Deferasirox is an iron chelation therapy used to remove excess iron from the body in patients who require regular blood transfusions, such as those with thalassemia or sickle cell disease. It works by binding to iron in the bloodstream and facilitating its elimination through the urine and feces, helping to prevent iron overload and associated complications.
Deferoxamine: Deferoxamine is a medication used to treat iron overload, a condition where excess iron accumulates in the body's tissues, particularly in individuals who have received frequent blood transfusions or have certain genetic disorders. It functions as an iron chelator, binding to and removing excess iron from the body, preventing the harmful effects associated with iron overload.
Electrolytes: Electrolytes are minerals that carry an electric charge when dissolved in body fluids such as blood, urine, and other bodily fluids. They are essential for maintaining proper hydration, regulating nerve and muscle function, and supporting cardiovascular and renal health.
Elemental iron: Elemental iron is the amount of pure iron available for absorption in dietary supplements and foods. It is crucial for the production of hemoglobin and red blood cells, impacting overall hematologic health.
Erythropoietin: Erythropoietin (EPO) is a glycoprotein hormone produced primarily by the kidneys that stimulates the production of red blood cells (erythrocytes) in the bone marrow. It plays a crucial role in the regulation of red blood cell production and is closely linked to the hematological system and renal function.
Folate Antagonists: Folate antagonists are compounds that interfere with the utilization or absorption of folate, a essential B vitamin necessary for various metabolic processes in the body. These antagonists can disrupt normal folate metabolism, leading to potential health consequences.
Hematologic malignancies: Hematologic malignancies are cancers that affect the blood, bone marrow, and lymphatic system. Common types include leukemia, lymphoma, and multiple myeloma.
Hypogonadism: Hypogonadism is a condition characterized by reduced or absent secretion of sex hormones from the gonads. It can affect both males and females and can lead to various health issues, including impacts on hematologic health.
Hypothyroidism: Hypothyroidism is a condition where the thyroid gland does not produce enough thyroid hormones. This leads to a slower metabolism and can affect various bodily functions, including energy levels and nutrient absorption.
Immunosuppressive Drugs: Immunosuppressive drugs are medications that reduce the strength of the body's immune system, typically used to prevent organ rejection in transplant patients or to treat autoimmune disorders. These drugs work by interfering with the activation and proliferation of immune cells, thereby dampening the overall immune response.
Iron Chelation Therapy: Iron chelation therapy is a medical treatment used to remove excess iron from the body, particularly in individuals with iron overload conditions such as hemochromatosis or those who have received multiple blood transfusions. This therapy involves the use of chelating agents that bind to and facilitate the elimination of excess iron from the body.
Iron overload: Iron overload is a condition where excess iron accumulates in the body, potentially leading to toxic effects and organ damage. It is often caused by genetic disorders or repeated blood transfusions.
Iron Overload: Iron overload is a condition in which the body accumulates excessive amounts of iron, leading to potential health complications. This term is particularly relevant in the context of treatments and nutrition, as managing iron levels is crucial for maintaining overall health and well-being.
Iron is an essential mineral that plays a vital role in the body, but when present in excess, it can cause damage to various organs and tissues. Understanding the causes, symptoms, and management of iron overload is essential for healthcare professionals and individuals seeking to optimize their health.
Iron supplement: Iron supplements are dietary supplements used to treat or prevent iron deficiency anemia. They help in the production of hemoglobin, which is essential for carrying oxygen in the blood.
Iron Supplements: Iron supplements are oral medications or dietary supplements that provide additional iron to the body, typically for the treatment or prevention of iron deficiency anemia. They are an important component in the context of treatments and nutrition.
Low-microbial diet: A low-microbial diet is a specialized dietary approach that aims to minimize the intake of foods containing high levels of microorganisms, particularly pathogenic bacteria, in order to reduce the risk of infection or complications for individuals with weakened immune systems or specific medical conditions.
Malnutrition: Malnutrition refers to a state of nutritional imbalance, where an individual's intake of nutrients is either insufficient, excessive, or imbalanced, leading to adverse effects on their health, growth, and overall well-being. This term is particularly relevant in the context of nursing practice, population health, and the care of vulnerable populations.
Methotrexate: Methotrexate is a medication primarily used to treat certain types of cancer, autoimmune disorders, and inflammatory conditions. It works by interfering with the body's use of folate, a nutrient essential for cell division and growth.
Mucositis: Mucositis is a painful and debilitating condition characterized by inflammation and ulceration of the mucosal lining of the digestive tract, often as a side effect of cancer treatments such as chemotherapy and radiation therapy. It can significantly impact a person's ability to eat, drink, and swallow, making it a critical consideration in the context of treatments and nutrition.
Multiple myeloma: Multiple myeloma is a type of blood cancer that affects plasma cells in the bone marrow. It disrupts normal blood cell production and can impact various bodily functions, including immune response and nutrient absorption.
Myelodysplasia: Myelodysplasia, also known as myelodysplastic syndromes (MDS), is a group of disorders caused by poorly formed or dysfunctional blood cells. It often leads to anemia, infection, or bleeding due to the ineffective production of blood cells in the bone marrow.
Osteoporosis: Osteoporosis is a condition characterized by weakened bones, increasing the risk of fractures. It occurs when bone mineral density and bone mass decrease, or when the quality or structure of bone changes.
Osteoporosis: Osteoporosis is a chronic, progressive skeletal disorder characterized by a decrease in bone mass and deterioration of bone tissue, leading to an increased risk of fractures. This condition is closely linked to various aspects of nutrition, including protein, vitamins, minerals, and supplements, as well as its impact on the musculoskeletal and integumentary systems across the lifespan.
Pulmonary hypertension: Pulmonary hypertension is a condition characterized by high blood pressure in the arteries of the lungs. This leads to increased workload on the right side of the heart and can result in heart failure if untreated.
SCD: Sickle Cell Disease (SCD) is a genetic blood disorder characterized by the production of abnormal hemoglobin, leading to rigid, sickle-shaped red blood cells. These malformed cells can obstruct blood flow and cause various health complications.
Sickle Cell Disease: Sickle cell disease is an inherited blood disorder characterized by abnormal hemoglobin, which can cause the red blood cells to become sickle or crescent-shaped. This shape change can lead to various complications and health issues across the lifespan, requiring specialized nutritional considerations.
Stem Cell Transplantation: Stem cell transplantation is a medical procedure in which stem cells are transplanted into a patient to treat or prevent a disease. Stem cells are undifferentiated cells that have the ability to develop into various cell types in the body, making them a valuable tool in the treatment of a wide range of conditions, including cancer, blood disorders, and autoimmune diseases.
Thalassemia: Thalassemia is a genetic blood disorder characterized by less hemoglobin and fewer red blood cells than normal. This can lead to anemia, fatigue, and other complications.
Thalassemia: Thalassemia is a group of inherited blood disorders characterized by the body's reduced or absent production of hemoglobin, the oxygen-carrying protein in red blood cells. This leads to anemia, which can have significant impacts on an individual's health and wellbeing across the lifespan.
Thrombosis: Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. It can lead to serious health complications such as stroke, heart attack, or pulmonary embolism.
Vitamin K: Vitamin K is a fat-soluble vitamin that plays a crucial role in blood clotting, bone health, and various other physiological processes. It is essential for the proper functioning of the body and is involved in several topics covered in the course, including nutrition, vitamins, supplements, hematological wellness, and the impact of nutrition on the musculoskeletal and integumentary systems.
Warfarin: Warfarin is an anticoagulant medication used to prevent and treat blood clots by reducing the body's ability to form clots. It is commonly prescribed for individuals at risk of developing blood clots, such as those with atrial fibrillation, deep vein thrombosis, or recent heart valve replacement.