The polyneuritic psychosis or Korsakoff's diseasel is an affection characterized by the association of phenomena of polyneuritis with specific mental disturbances among which amnesia of diverse forms constitutes a preponderant feature. Although it occurs most frequently on a basis of chronic alcoholism, it is also sometimes observed independently of chronic alcoholism, following a profuse hemorrhage or an infectious disease, such as influenza.

Symptoms

In some cases the symptoms of the polyneuritic psychosis appear gradually, without any striking phenomena at the onset; much more often the onset is acute: agitation, numerous hallucinations, and anxiety render the resemblance to delirium tremens so marked as to lead frequently to errors in diagnosis. After several days the agitation subsides, but the disorientation persists and the characteristic amnesia appears together with the phenomena of polyneuritis.

1 Congres De Mekiecine, 1889

Luckerath. Beitrag zu der Lehre von der Korsakow'schen Psychose. Neurol. Centralblatt, April, 1900.

The amnesia is both anterograde and retrograde.

The anterograde amnesia results from the total abolition, or at least a marked diminution, of the power of fixation. The patient forgets in a few moments a visit which he has received or the gist of what he has just read. On leaving the table he asks whether it is not almost time for dinner and complains of having no appetite.

The retrograde amnesia is purely functional, by default of reproduction; in the course of time old representations reappear intact.

The effacement of representations occurs in conformity to the law of retrogression. Depending upon the severity of a particular case, the amnesia involves the events of a more or less considerable period of time.

Pseudo-reminiscences, illusions and hallucinations of memory fill the gaps created by the amnesia. Thus quite frequently the patient is totally unconscious of his disorder of memory and unhesitatingly replies to all questions put to-him. Often also, modifying facts of which his impression is more or less vague, adjusting some details and suppressing others, the patient narrates imaginary occurrences the principal features of which are their mobility, their easy modifiability by appropriate suggestion, and their being usually limited to the bounds of possibility. The latter characteristic is, however, not constant, for the fabrications in the polyneuritic psychosis may be altogether improbable or even absurd.

The following specimen has been taken from an observation made upon a case of polyneuritic psychosis due to absinthe:

Q. How long have you been here? A. Since this morning. Q. What were you doing yesterday?

A. I went to the market to buy some eggs. After that I went to see my sister and took dinner with her.

Q. Don't you ever go to the theatre?

A. Oh, that's true, ... I went there after work last night . . . it was very beautiful.

Q. What play did you see?

A. Really . . . just wait a minute ... it was very beautiful . . . they sang . . . they had superb costumes ... I cannot recollect the name of the play.

In reality the patient, who had been in the hospital during the three weeks previous, had not left his bed since his admission on account of very marked paresis of both lower extremities.

To these pathognomonic disturbances of memory are added also complete loss of orientation of time and place, numerous illusions which often lead to mistakes of identity and occasional hallucinations which are more or less fleeting.

The emotional tone is usually one of indifference; sometimes there is slight euphoria or undue irritability.

In spite of their intensity the psychic symptoms are in many cases not very apparent at first. The patients are quiet, understand well the questions put to them, and reply in a calm and often even in an intelligent manner. They often appear to be normal because a conversation of several minutes may not suffice to reveal the pathognomonic amnesia and disorientation.

The signs of polyneuritis, paresis of the lower extremities, abolition of the tendon reflexes, paresthesias, pains, hyperesthesias of circumscribed muscular masses - to mention only the principal ones - vary widely in intensity. They are at times mild, while the mental disturbance may be quite marked. Possibly they may be even entirely wanting in certain cases that are perfectly typical from the psychic standpoint.

The general health is usually affected to some extent. Occasionally cachexia may develop and end fatally. Also cardiac disturbances are often noted, feeble action, irregularity, etc., which in a number of cases are dependent upon a neuritis of the pneumogastric nerve.

Duration, Prognosis, Diagnosis

The duration of the active period of the disease is usually several months, seldom over a year. There then remains a characteristic state of mental deterioration dependent upon a persisting and more or less pronounced impairment of the power of retention, with resulting disorientation and amnesia for recent occurrences. The tendency toward active fabrications and pseudo-reminiscences becomes less marked and often disappears.

In some few cases there is partial restoration, so that the patients are again able to keep track of dates and current events, but complete recovery is a rare exception in alcoholic cases, though it is said to be common in cases with a different etiology.

Another mode of termination, also infrequent, is death, which results either from cachexia or from some complication: influenza, pneumonia, tuberculosis.

The diagnosis is based on (a) the very marked and characteristic disorders of memory; (b) apparent lucidity of the patient, contrasting with the real disorientation; (c) coexisting signs of polyneuritis.

Treatment

Treatment in the acute stage of the disease consists chiefly of rest in bed combined with a reconstructive diet.

It is scarcely necessary to add that abstinence from alcohol should be rigorously enforced, especially where alcoholism is the cause.