Ok there genius. The medical term is Radiculopathy and the result is Myopathy. i.e. The nerve is affected and the muscle that it innervates atrophies as a result.
However, since the most common cause of a radiculopathy is a herniated disc or degenerative changes in the cervical spine (which undoubtedly Ronnie has from years of intense training) the likelyhood that he has affected the C4 on down to the T-spine , in order to knock off the triceps c8, Biceps c67 and Lat Dorsi including errectors is incredibly low. The only condition i'm aware of that would do such is a stroke. And, we will never know if he has had one, because, sad to say his speech was exactly coherent before any of these changes. 
THANK YOU JACKASS
Like I said ass the problem is nerve compression whether you like to hear it or not and having experienced it myself and all of its effects I can speak from personal experience where as you are speaking ignorance...as expected.
A nerve compression from a herniated disk or inflammation can effect a nerve root or the spinal cord. A cord compression is the most severe and can have an adverse effect on a vast area of the body involving multiple limbs or areas. I did not go into all the details on myself, because for those who know (unlike yourself) it is clear. I am sure ALL of the issues he is experiencing is from the compression be it multiple nerve roots or the spinal cord; and once the compression is relieved either through physical therapy, spinal decompression (intermittent traction) or surgery he will get better. I just hope he doesn't have any long lasting effects from this compression. Treating a spinal compression as soon as possible is best to keep from having long term if not life long nerve damage and trouble. So far as muscle atrophy is concerned that is not that case with him...his muscle have flattened out..which is the result of reduced nerve signal from the compression. For atrophy to occur he would have had to have lost all use of the limb:Triceps, for it to really atrophy. But obviously since he is still able to bench, shoulder press and do triceps workouts as well as back, that shows the muscle is still receiving nerve signals, but at a reduced level, which makes the muscle appear smaller or torn away (flattened). Once the compression is relieved the muscle will literally spring back to size...I know, because it happened to me.
Oh and so far as any STROKES go...I believe it is you who has had the stroke with this level of ignorance. For a stroke to go so deep as to effect ones speech...I hardly think that the person would be able or willing to continue working out let alone using the drugs and hard dieting necessary to do another BB show.... But if there was any chance in HELL that a stroke was the case, THEN RONNIE IS ONE BADASS MUTHA FUCKA for being able to do it.
