A neurologist involved in many different areas of study. A large part of his work was concerned with the effect of brain trauma on consciousness and perception (see The Man Who Mistook His Wife For A Hat).

He was dramatised by Robin Williams in the film Awakenings, based on Sach's book of the same name, detailing his treatment of encephalitis, commonly known at the time as 'Sleeping Sickness'.

He has also done work with Parkinson's Disease and Tourettes Syndrome, and filmed a documentary entitled 'Shane' following the life of a Tourette's Syndrome sufferer. Shane himself made a small cameo in the film Awakenings as a Tourette's Syndrome patient.