Subjective experience of 'Stream of Consciousness Impairment' in three patients with severe amnesia.

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 examine an unusual phenomenon in which severely amnesic patients recurrently report the belief that they have just awakened from an unconscious state. A famous case illustrating this phenomenon was that of Clive Wearing who repeatedly wrote 'I am now awake' in his diary. This unique cognitive phenomenon has not been specifically studied until now. We report three new patients who described similar subjective experiences. All three patients suffered from autoimmune encephalitis and showed 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, we experience an uninterrupted flow of consciousness. This condition should be added to the spectrum of neurological symptoms that contribute to the study of memory and consciousness in humans.