Speaking of her pain at her mother's gradual decline before her death in 1990, Rowling said: "When I left home, she was walking unaided. By the time I graduated, she was in a wheelchair and in the house she needed a walking frame.
"It was awful to watch."
Rowling, whose Harry Potter novels have been transformed into a globally successful film series, said her mother had shown marked signs of the illness for six or seven years before she was diagnosed.
A numbness in her right arm had spread over half her torso in a year.
In 2006, multi-millionaire Rowling made a major cash donation towards a multiple sclerosis research centre at Edinburgh University to help find a cure.
She has now hit out at a perceived general lack of funding for, and interest in the condition, which affects about one in every 500 people in Scotland.
"It's a Cinderella of illnesses, you hear this all the time, because it's under-funded, because it's ignored," she said.
"I think it's possibly common to a lot of neurological conditions. It just seems to be an area that has not seemed very sexy for funding."
Rowling, patron of the Multiple Sclerosis Society Scotland, added: "People get diagnosed and sent home. It's a frustration to those of us whose family members do have MS that so little is being done, because it is a life-altering condition and a lot can be done now, so why isn't that happening?"
Scotland's Hidden Epidemic: The truth about MS, will be broadcast on Wednesday 23 July, on BBC One Scotland at 2245 BST.
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