Why does my loved one all of a sudden have no strength?

It definitely sounds neurological...I am surprised that they ruled out stroke. When something comes on this swiftly it is usually a stroke. The other thing to consider is a virus...they also move quickly and can have a variety of symptoms.
I have had good luck by using medical websites and typing in sypmtoms.
Has he traveled recently? Does he have a history of high blood pressure? Did he have a brain scan?
I am hoping that another forum member who has had this exact thing happen, pipes in.

The hospital stay ruled out virus things. He has not traveled or have high blood pressure. They ruled it out because he didn't have other signs such as slurred speech, or any signs of stroke on one side of the face or body. Anyway he is home, requires more assistance, and is doing better. Still doesn't want to bathe, brush teeth, exercise, and other signs of dementia/alzheimers.

Keep you eyes and ears open for Ischemic Stroke. Slurred speech may not be present. Speaking in a foreign language, or jibberish is also a sign of stroke.
I assume he has had an Echo and an EKG. Passive exercise of his legs might help a lot....that's when someone else moves the patient's legs for him.

My dad experienced similar symptoms. He had a severe bacterial infection in his blood stream. He was very ill for about 6 weeks. This too should have been ruled out during your dads hospital stay. Hope He continues to get better.

Readan article on the web one time, a younger man with similar symptoms, after diqgnosing him with binswangers dementia, found out he had an allergy to glutin. A substance found in lots of foods. He improved dramaticaly after being treated and given a gluten free diet.

N1k2R3-He did have an echo done and they still ruled out tia stroke, which is a mini stroke. I will watch him. His home health nurses are also watching him. He can dress, eat, etc. Problem-he thinks he is now able to drive me to work. I'm not ready for him to. When should I trust his ability to drive. I think after the heart doctor visit on the 18th. Thanks for your input!

He can never drive again.

You just said he could never drive again. You didn't say whether he needs a doctor to say that, or how I am to tell him that, or anything else. The stroke was ruled out, on what basis do you mean he can't drive again?

I'm glad he is improving. I hope he improves completely, back to his old baseline. Driving is a serious responsibility with risks to other people. When my husband's ability to return to driving was in question I took him to a rehabilitative services place with specialized testing. Their services include helping people with physical handicaps but normal mental capabilities determine the need for adaptive modifications to their vehicles, and determining if injured or ill people have regained the needed skills and abilities to drive safely. I think that the suggestion that your husband undergo such an evaluation would be best coming from a medical professional rather than you. Do you have someone you can talk to about that?