Harry Potter and Back to the Future star Drew Struzan has been diagnosed with Alzheimer’s disease, his wife has confirmed.

Best known for his illustration work on films including the Star Wars series, E.T., The Shawshank Redemption, and Blade Runner, Drew was responsible for creating the cover art for the Harry Potter films.

Born in 1947, the 78-year-old has won numerous awards for his artwork.

His wife, Dylan, addressed his Instagram followers with an emotional post, writing:

“Good morning all. I’m Drew’s wife, Dylan Struzan. I come to you with a heavy heart. Several years ago, Drew was diagnosed with Alzheimer’s Disease. As you may know, the early stages are a slow progression of forgetfulness. This happens in the brain when the proteins in the neurones begin to fold improperly. They are called tau tangles. Neurotransmitters can no longer transmit a thought. Think of it as a log jam. Forgetfulness is often what we think of when this disease is mentioned, the brain malfunctioning.

“As the disease progresses, the hippocampus (seat of memory) begins to fail. Think of all the things you learned throughout life, simple things like how to stand (balance), how to walk, how to talk, how to control your bodily functions, how to make decisions, how to do most everything we do. The hippocampus forgets.”