Can my unsteadiness and imbalance be due to only spine issues or Parkinson’s or both?

I am 46 years male. I have been experiencing unsteadiness and imbalance for about 2 years now. This is the main symptom. I also have severe sleep apnea. My right hand has a reduced swing while walking. I have a postural tremor, but it has been there for many years. My speech sometimes chokes up suddenly while talking, and i have to clear my throat to continue. I also feel light headed once in a way, this is diff from the unsteadiness and is independent of posture etc.

My doctors suspects it is early Parkinson’s.

A spine MRI showed cervical compression in c6-c7, c5-c6 with myelopathic changes last year. This year I repeated MRI, but now it says myelomalacic changes in c6 c7. A spine surgeon advised me surgery.

Can my symptoms be due to only spine issues or Parkinson’s or both? What are myelomalacic changes? What will it lead to if I do not have surgery? I don’t have any significant pain symptoms. But hand is slightly weaker (weaker grip). Doctor says 4 out of 5 (strength).