What is the theme in The Man Who Mistook His Wife for a Hat and Other Clinical Tales by Oliver Sacks?

The self and mental illness work into the themes. By depicting the lives of his patients in story form, Sacks brings back an important element many mental patients are stripped of: the self. The reader must question who or what robs the mental patient of the self. Is it the disease or the medical world which professes to want to help these individuals?