Changes in the H-reflex during a preparatory brain potential in hemiparetics with a focal ischaemic brain lesion

Abstract

1.One hundred and five cases of general paralysis were inoculated subcutaneously (very rarely intravenously) with malaria—ninety-eight with simple tertian, six with quartan, and one with malignant tertian. Information is given regarding the incubation period and character of the fever, and the mode and result of treatment.2.During the last twenty months a strain of P. vivax has been transmitted by direct subcutaneous inoculation through twenty-three passages involving seventy cases. This procedure has apparently not been attended by any change in the parasite.3.Forty-one cases of general paralysis were infected with P. vivax by the bites of infective Anopheles. Information is given regarding the incubation period, and the mode and result of treatment.4.Both A. maculipennis and A. bifurcatus were used for this purpose and proved equally susceptible to infection with P. vivax, and equally capable of transmitting the parasite to man.5.Evidence is adduced which, in our opinion, renders the unicity hypothesis of the malaria parasites of man untenable.6.The malaria infections, whether induced by inoculation of virulent blood or by the mosquito, proved extraordinarily susceptible to treatment, a short course of quinine, grs. 30 for three consecutive days, being sufficient to sterilise the infection in sixty of sixty-one inoculated cases and in twenty-seven of thirty-one mosquito-infected cases. These successes are contrasted with the frequent failures obtained in the treatment of simple tertian malaria during the war and in ordinary practice.7.Various hypotheses which have been advanced to explain the susceptibility of the induced malaria to treatment are considered, and found to be unsatisfactory.8.Evidence is produced to show that the susceptibility to treatment in the induced malaria is bound up with the fact that in these cases one is concerned with the treatment of primary infections.9.The mechanism by which a cure is obtained in malaria is considered at length, and the conclusion reached that the essential factor for the production of cures is the capacity of the host to produce immune-body in response to antigen formation, resulting from the destruction of a considerable number of parasites by a medicament. If, for any reason, the immune-body formation is insufficient, the infection is not sterilised and a relapse occurs.10.The failure of treatment in chronic relapse cases is explicable on the same hypothesis; the parasites in such cases are not quinine resistant, but immune-body resistant.11.Observations on the value of quinine prophylaxis showed that administration of the drug before infection is useless; that its administration must be continued for at least ten days after the infecting feed, to prevent infection from developing; and that the daily dose given has but little influence apart from the fact that with very large doses (30 grains) the period for which the drug has to be given to prevent development of infection is a little shortened. It is concluded from these observations that quinine has little, if any, action on sporozoites, and that the mechanism by which development of infection is prevented is similar to that by which a cure is effected.12.So far as can be judged at present, the results obtained with the malaria treatment of general paralysis are most satisfactory. Of the eighty-four paretics, who have been observed for a sufficient time after treatment to warrant any conclusion, twenty-three (27·4 per cent.) have been, or are about to be, discharged as provisionally cured, seventeen (20·2 per cent.) have showed distinct mental and great physical improvement, and many of the remainder have improved physically.