Talk to General Physician on Right Side Paralyzed- Gradually Increasing (what's The Diagnosis?)

Dear Drs, my father who has been very active throughout his life, no apparent issue of heart or anyother sort, gradually felt numbness in right arm and right leg. but still he was doing fine for months, very slowly and gradually his ability to walk started reducing. consulted neurologists, but nothing seemed to improve.. instead his health kept on deteriorating. Can someone help to understand what is the actual issue? what's the diagnosis? Can it be the issue with spinal cord? His neck x-ray shows some thinning in disk space.. X-ray report attached. MRI report is also attached.