These drugs have only a few clinical uses, mainly in augmenting gastric and intestinal contractions (in treatment of obstructions of the digestive tract) and in augmenting muscular contractions in general (in the treatment of myasthenia gravis).
Approximately 75 percent of individuals with myasthenia gravis have an abnormal thymus.
It can also result from muscular diseases (such as muscular dystrophy or myasthenia gravis) or damage to the oculomotor nerve from diabetes, hypertension, atherosclerosis, trauma, or direct compression.
Such agents include physostigmine and neostigmine, which are used to help augment muscle contraction in certain gastrointestinal conditions and in myasthenia gravis.
In myasthenia gravis, autoantibodies bind to the receptors, preventing acetylcholine from binding to them and thus preventing the muscle from responding to the nerve signal.
Treatments for myasthenia gravis include anticholinesterase medications, which stimulate the transmission of nerve impulses, and corticosteroids, such as prednisone, which dampen the immune response.
Causes of binocular diplopia include myasthenia gravis, inflammatory processes, thyroid eye disease (Graves ophthalmopathy), small blood vessel disease (e.g., diabetes mellitus), trauma, infections, and various tumours.
The autoimmune reaction underlying myasthenia gravis results from a malfunction in the immune system in which the body produces autoantibodies that attack specific receptors located on the surface of muscle cells.
One group of acetylcholinesterase inhibitors (anticholinesterase drugs) is used to treat myasthenia gravis, a disorder characterized by muscle weakness.
Local lesions of the brainstem may also cause paralysis of eye movement, as may severe myasthenia and myopathies affecting the eye muscles.
Causes of bulbar palsy include motor neuropathies, such as diphtheria, poliomyelitis, and botulism, motor neuron diseases, myasthenia gravis, certain muscle diseases, and compression of the nerves by tumours.
