Transient pain in head, stumbling,dizziness

My mother-in-law is 75 and for about a year has had stumbling, increased short-term memory problems, and recently,dizziness and a severe pain in the top of her head on and off. Today, she fell in her bedroom. She states that she just loses her balance. Her memory has gotten so bad lately that she is constantly losing items and cannot remember telling you of something and can't remember what has been told her. She does have a diagnosis of autonomic neuropathy.  She had a brain CT or MRI (to determine if she had Alzheimer's or some sort of dementia) a few months ago which they said was OK. Her neurologist keeps just telling her it is her neuropathy, but doesn't give her any new medication or increase any that she presently takes. Also, sometimes her speech is slurred and she sounds weak. These symptoms seem to be transient somewhat. In the AM she may feel fine but in the afternoon she is worse. Any ideas would be appreciated. Thanks!

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You may want to take her to a geriatric specialist, not just any neurologist.
The fact that the decreases in the afternoon is a sign of "sundowning" and they need to take that seriously.
I had a MIL with dementia and trust me, the stages they list do not come in order. Some come fast, some come in parts, and should be used as a guide.
You need to post under Alzheimers disease (which is just one form of dementia) for more info than we can give here. I will have the post moved.
If you contact your local Alzheimers association, they can help you locate a doctor and assist you.