One of the strangest neurological cases occurs when the patient has lost vision, is totally blind, but the patient is not aware of it: in fact, he denies it, and pretend you're looking perfectly.
It is the case that, for example, describes Kathryn Schulz in his book In defense of error, in which he talks about Hannah, a 46-year-old woman who underwent a neurological examination in a hospital in Vienna in 1992.
Hannah had suffered a stroke which had almost completely destroyed her visual cortex and left her almost unable to move due to the loss of muscular coordination and chronic epileptic contractions.
The neurologist, Georg Goldenberg, began by asking Hannah to describe the doctor's face. It was a strange question, but Hannah obeyed. The doctor had slightly tanned hair. Next, Goldenberg asked Hannah for an object that was in front of her. It was a notebook, he replied, of the kind used by schoolboys, with a brown cover and something written in the Latin alphabet that I couldn't distinguish with precision. And then the doctor asked him where exactly the notebook was. He had it in his left hand, Hannah replied, raised at eye level.
Actually, Goldberg's face was hidden behind a screen. And the book that showed him was not such, but a comb. This type of blindness, which consists in being blind to one's blindness, is called Anton syndrome.
It is part of a collection of neurological problems called collectively as anosognosia or denial of the disease. For example, there are patients who deny suffering paralysis even if they are suffering from it.
An illustrious (and illustrative) victim of this strange syndrome, the late William Douglas, Supreme Court judge, said he had no physical problems and happily invited a journalist who reported his stroke to take a walking tour with him.
Denial of paralysis, in any case, is more common than Anton syndrome, which it is certainly a very rare disorder. Usually other neurological symptoms are present that are very variable depending on the cause and extent of the brain injury. There may be symptoms of dementia, delirium and amnesia if the temporal lobe is affected.