I recommend Diane Ackerman's latest book, One Hundred Names for Love.
I love all of her books but this one is especially poignant and inspiring. Her husband had a stroke and she writes of his movement from immobility and an inability to speak more than "mem" to a man who can swim and go back to writing books.
They shared a rich linguistic legacy and she uses that to bring him back, but it shows, absolutely proves, what can be done when we exercise and stimulate the mind.
They played a game of mental solitaire for two before the stroke. Here is a way to begin.
What can you do with a pencil other than write?
Read the book to get their list and be inspired by your own.