Experimental neurological syndromes and the new drug therapies in psychiatry.

C ONSIDERING the fact that encephalitis lethargica practically disappeared before its virus was identified, the disease would have been important only out of historical interest and also because of the progress in neurology which it led to. However, the illness developed fresh significance as result of the striking similarities which cxist between the sequelae of the disease and the nervous syndromes induced, in reversible and ahnost experimental fashion, by those drugs which we call "neuroleptics." Somnolence or changes of the sleep pattern, modifications of psychomotility and of the neuromuscular tonus, and production or reduction of abnormal mental phenomena are the three factors common to the action of neuroleptic agents and to the pathology of encephalitis which we will consider in their mutual relationship. Ever since wc first, in 1952, together with Jean Delay, experimented with Chlorprolnazinc, we have observed that this drug produces a very unique syndrome of psychomotor indifference which is today generally known. Since then we found in the literature a very similar condition, described under the name of "'Syndrome akineliqtte sans hypertonie'" (akinetie syndrome without hypcrtonia) by j. Lhermitte a~ in Iris 19"9_3 report on sequelae of cnceplmlitis lethargica. If one compares this description with the one of the effects of chlorpromazine given by us/ one might ahnost get the impression that one has been copied from the other. From the fact that this condition is not yet accompanied by hypertonia, the author infers tlmt the akinesia of the patient suffering from parkinsonism is more than anything else a disorder of psychomotility. At the same time, he stresses the generalized slowing of motion (bradykinesia), the loss of natural associated movements, the condition of "dencrvation musculaire" (diificulty of relaxation of antagonists), the micrography (again found in patients treated with neuroleptic drugs) and 'Tasthenie" (low energy level). Since, however, his patients were "tunaed into stone" in an attitude of complete indifference or stupor and had lost all initiative and all movement, the syndrome of Lhermitte appeared more intense and severe than the condition usually observed with neuroleptics. Today, of course, we possess new, more powerfid neuroleptics which can, in a few hours, produce the akinetie syndrome in all its intensity. The psychiatric application of reserpine, on the other hand, with indications almost overlapping those of chlorpromazine, became known in 1954. Althougl~ the administration of reserpine is followed by asthenia rather than indifference, its different and at times opposite autonomic actions have effects upon the same functions and are also important. Similarities between the two drugs