“Stream of Consciousness Impairment” in Severe Amnesia: A Novel Aspect of Temporal Disorientation

Orientation in time is a central aspect of human cognition. Because orientation in time is intimately related to autobiographical episodic memory, most amnesic patients suffer from temporal disorientation. Patients with severe anterograde amnesia have been described as "stuck in time"; their mental time travel abilities are altered, and they seem to live in the present. Here, we look at the very special situation of complete temporal disorientation, to the point where the patient seems to have no sense of the passage of time. A famous case illustrating this phenomenon was that of Clive Wearing who repeatedly wrote “I am now awake” in his diary, showing his recurrent belief that he had just awakened from an unconscious state. This unique cognitive phenomenon has not been specifically studied. We report cases involving three patients who described similar experiences. All three patients suffer from autoimmune encephalitis and show massive bilateral hippocampal inflammation causing severe anterograde amnesia. We propose to call this phenomenon “Stream of Consciousness Impairment”, a reference to William James’s theory according to which, normally, there is an uninterrupted flow of consciousness. This condition could be added to the spectrum of neurological disorders that contribute to the study of consciousness in humans.