In an advanced stage, distal impairment may become apparent, but respiratory, bulbar, and facial muscles are spared.
The diaphragm, tongue and extraocular muscles are spared from FOP. Cardiac muscle and smooth muscle are not affected (Connor and Evans, 1982).
2 3 One case control study demonstrated that MV results in increased proteolysis and atrophy in the diaphragm muscle, while other skeletal muscles are spared.
We therefore conclude that muscle wasting appears to be a generalized response to tumor-burden, even though we cannot exclude that some muscles are spared (which would be demonstrated only by a systematic analysis on virtually the entire musculature).
For example, oculopharyngeal muscular dystrophy is associated with severe atrophy restricted to FG fibers, while oxidative fibers in the soleus muscle are spared [49].
In the late-onset forms, caused by a partial enzyme deficiency, cardiac muscle is spared, but slowly progressive skeletal muscle weakness leads to wheelchair and ventilator dependence, and premature death from respiratory insufficiency [3].
However, the soleus muscle was spared from tumor-induced atrophy.
Skeletal muscles are also involved in the ossification process; however, smooth muscle and cardiac muscle are spared [ 28].
Interestingly, the Soleus muscle showed a smaller, non significant decline in the fatigue time, indicating that resistance of this muscle is spared in cachexia.
