G70.0 - Myasthenia gravis

Clinical Information

• Myasthenia Gravis-. a disorder of neuromuscular transmission characterized by fatigable weakness of cranial and skeletal muscles with elevated titers of acetylcholine receptors or muscle-specific receptor tyrosine kinase (musk) autoantibodies. clinical manifestations may include ocular muscle weakness (fluctuating, asymmetric, external ophthalmoplegia; diplopia; ptosis; and weakness of eye closure) and extraocular fatigable weakness of facial, bulbar, respiratory, and proximal limb muscles. the disease may remain limited to the ocular muscles (ocular myasthenia). thymoma is commonly associated with this condition.
• Myasthenia Gravis, Autoimmune, Experimental-. any autoimmune animal disease model used in the study of myasthenia gravis. injection with purified neuromuscular junction acetylcholine receptor (achr) (see receptors, cholinergic) components results in a myasthenic syndrome that has acute and chronic phases. the motor endplate pathology, loss of acetylcholine receptors, presence of circulating anti-achr antibodies, and electrophysiologic changes make this condition virtually identical to human myasthenia gravis. passive transfer of achr antibodies or lymphocytes from afflicted animals to normals induces passive transfer experimental autoimmune myasthenia gravis. (from joynt, clinical neurology, 1997, ch 54, p3)
• Myasthenia Gravis, Neonatal-. a disorder of neuromuscular transmission that occurs in a minority of newborns born to women with myasthenia gravis. clinical features are usually present at birth or develop in the first 3 days of life and consist of hypotonia and impaired respiratory, suck, and swallowing abilities. this condition is associated with the passive transfer of acetylcholine receptor antibodies through the placenta. in the majority of infants the myasthenic weakness resolves (i.e., transient neonatal myasthenia gravis) although this disorder may rarely continue beyond the neonatal period (i.e., persistent neonatal myasthenia gravis). (from menkes, textbook of child neurology, 5th ed, p823; neurology 1997 jan;48(1):50-4)
• Myasthenic Syndromes, Congenital-. a heterogeneous group of disorders characterized by a congenital defect in neuromuscular transmission at the neuromuscular junction. this includes presynaptic, synaptic, and postsynaptic disorders (that are not of autoimmune origin). the majority of these diseases are caused by mutations of various subunits of the nicotinic acetylcholine receptor (receptors, nicotinic) on the postsynaptic surface of the junction. (from arch neurol 1999 feb;56(2):163-7)

Specific Coding for Myasthenia gravis

Non-specific codes like G70.0 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10 codes with a higher level of specificity when coding for myasthenia gravis:

Patient Education

Myasthenia Gravis

Myasthenia gravis is a disease that causes weakness in your voluntary muscles. These are the muscles that you control. For example, you may have weakness in the muscles for eye movement, facial expressions, and swallowing. You can also have weakness in other muscles. This weakness gets worse with activity, and better with rest.

Myasthenia gravis is an autoimmune disease. Your body's immune system makes antibodies that block or change some of the nerve signals to your muscles. This makes your muscles weaker.

Other conditions can cause muscle weakness, so myasthenia gravis can be hard to diagnose. Tests used to make a diagnosis include blood, nerve, muscle, and imaging tests.

With treatment, the muscle weakness often gets much better. Medicines can help improve nerve-to-muscle messages and make muscles stronger. Other drugs keep your body from making so many abnormal antibodies. These medicines can have major side effects, so they should be used carefully. There are also treatments which filter abnormal antibodies from the blood or add healthy antibodies from donated blood. Sometimes, surgery to take out the thymus gland helps.

Some people with myasthenia gravis go into remission. This means that they do not have symptoms. The remission is usually temporary, but sometimes it can be permanent.

NIH: National Institute of Neurological Disorders and Stroke

Code History

• FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
• FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
• FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
• FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
• FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
• FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
• FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
• FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016 (First year ICD-10-CM implemented into the HIPAA code set)