My Mom Is 77 And Has ALS. A Really Bizarre

My mom is 77 and has ALS. A really bizarre thing has started to occur to her scalp/hair. We started to notice that her hair is becoming really oily like less than 24 hours after showering. Nothing has changed with hair products and she isn't bedridden or laying on her head all day. I washed it on Saturday and by sunday it looked as if it hadnt been washed in a week??