My stepfather had the same issue turned out to be a stroke, but it could also be muscle atrophy or something else... Take it seriously and see a doctor.
What Causes Droopy Left Eye, Tenderness On Left Side Of Scalp, And Lack Of Sweat?
Could possibly be a stroke, I would seek medical attention for what you describe sounds serious, I watched as my grandpa had several of these little strokes and I think if he would not have been so stubborn and seen a doctor, he would still be with us today