Ferrari. Mental disorders in combination with multiple neuritis. (Korsakov's Cerebropathia psychica toxaemica, Polyneuritis Psychosis by other authors). —The Alienist and Neurologist, January 1896, no. 1

Under the name Polyneuritis psychosis, Korsakov described a disease that differs from typical polyneuritis by the predominance of disorders on the part of the mental sphere. It begins with somatic symptoms vomiting, difficulty walking, pain and muscle atrophy; the electrical excitability of the muscles disappears, there are contractures; knee reflex disappears early, others remain normal or even increased. Death occurs from paralysis of the respiratory muscles. As for mental disorders, the last ones appear in the beginning of the disease in the form of simple irritability, after which amnesia comes to the fore.