James is your patient

James is your patient over the past few months he has had increasing

difficulty sleeping, difficulty getting up from his chair on his own, a mild tremor usually to his hand, has been taking small quick unsteady steps and often needs to be aided to start moving or steadied to stop, and has been speaking softer lately. His face has been increasingly expressionless when speaking to them.

What do you suspect could be wrong? What is your rationale for your response