Myasthenia gravis（MG） is a chronic autoimmune neuromuscular disorder that is characterized by fluctuating weakness of the voluntary muscle groups. In the most common cases, muscle weakness is caused by circulating antibodies that block acetylcholine receptors at the postsynaptic neuromuscular junction, inhibiting the excitatory effects of the neurotransmitter acetylcholine on nicotinic receptors at neuromuscular junctions.
Myasthenia gravis is treated with medications such as acetylcholinesterase inhibitors or immunosuppressants, and, in selected cases, thymectomy (surgical removal of the thymus gland).
ALS, , the term is commonly used as motor neurone disease In the United Kingdom.
Multiple sclerosis (MS) is a demyelinating disease in which the insulating covers of nerve cells in the brain and spinal cord are damaged.
重症肌無力（Myasthenia Gravis）並非神經退化，而是神經肌肉接頭的突觸後膜的乙酰膽堿受體被阻斷。該病可用乙酰膽堿酯酶抑製劑或免疫抑製劑藥來治療。
肌萎縮性側索硬化（Amyotrophic lateral sclerosis ）導致運動神經元退化，目前無藥可治。
多發性硬化症（Multiple Sclerosis）導致神經鞘退化，目前無藥可治，但有要可延緩。
後兩者與神經退化病變有關。寒枝的病人，神經萎縮型肌無力應屬於肌萎縮性側索硬化。
