Despite the fact that Feodor's hand shakes, and he has a difficult time walking and positioning and moving his body to get in and out of chairs, he remains mentally sharp. Feodor appears to have

Parkinson's disease.

Explanation:

Parkinson's disease is a progressive nervous system disease that comes as a disorder and affects its victim's movement. The symptoms start in a gradual form, sometimes the starting symptoms will be a barely noticeable tremor in just one hand. Tremors are the most common trait, but some victims might experience disorder and stiffness or slowing of movement.

Although Parkinson's disease is one of the most incurable diseases, judicious medications might drastically improve improve the situation positively. Occasionally, doctor may recommend going for surgery to normalize certain parts of your brain thereby improving your state.