Would you consider muscle weakness (M62.81) and back pain (M54.5) integral to Parkinson's?
You would not code the muscle weakness in addition to Parkinson's, because it is integral/a manifestation of Parkinson's. The back pain is a different story. If there is no definitive dx for the cause of the back pain, I would code the back pain in addition to the Parkinson's. back pain is not typically integral to Parkinson's like weakness, tremor, etc. are.