If the person with Huntington's disease stumbles frequently look to see if your furniture is strong enough to help them prevent falling when they reach out to grab it. While we are on the subject of grabbing, table lamps are easily knocked over. Try to move them to the corners of the room. With two walls to bounce off of or to use for support, many people with Huntington's disease do not have trouble in hallways. However, pictures on the walls can be easily knocked off the hook by someone stumbling against them.
Grab rails can help a person to move down the hall with a stable means of support.
The grab rail should be firmly anchored to a wall stud, not to the plaster of the wall. Use either wooden railings or metal grab bars from a medical supply house. Do not use towel racks or holders. They are not meant to be used as supports. Stairs are not a good place for someone who has trouble walking.