My Mother Fell Backwards And Punched A Whole In The

My mother fell backwards and punched a whole in the drywall behind her. She had a CAT scan and the conclusion was possible concussion, no bleeding or bruising or bump on the head. She is 93 years old. A week after the fall she started getting lightheaded. She had not told me of the fall so I thought she had low blood sugar (her eating habits are not good, says she's not hungry). I get her to drink Boost for snacks sometimes 2 times a day and we eat "regular meals". Is this lingering concussion, age, low blood sugar? She had recent labs and all is "normal". Also had a recent EKG and is good.