Myasthenia Gravis Support Group
Myasthenia gravis (MG) is a neuromuscular disease leading to fluctuating muscle weakness and fatiguability. The hallmark of myasthenia gravis is muscle weakness that increases during periods of activity and improves after periods of rest. Although myasthenia gravis may affect any voluntary muscle, muscles that control eye and eyelid movement, facial expression, and...
MG is sometimes difficult to diagnose as there appear to be several variations including two that are found by blood tests.
The first blood test will be AChR-Ab looking for the most common antibodies indicating MG. If that is negative, a second test may be performed, MuSK-Ab looking for a different set of antibodies.
However, if the first test is negative, you may have a test to determine muscle fatigue next.
You can read about various tests at http://www.myasthenia.org/WhatisMG/TestDiagnosticmethods.aspx
and all about MG at the same site -- www.myasthenia.org
Good Luck