Out of this chaos of symptoms the “trembling” neurosis stands out through its frequency and conspicuousness. You all know those pathetic creatures who hobble along through the streets with shaking knees, uncertain gait and peculiar motor disturbances. They give the impression of being helpless and incurable invalids; and yet experience shows that also this traumatic form of illness is purely psychogenic. A single treatment with electricity and suggestion, a few hypnotic sittings are often sufficient in rendering these men capable of doing some work, if only temporarily and under certain conditions. Erben has made the most careful investigation into these disturbances of innervation; he found that these disturbances are only suspended or increased when the respective group of muscles carry out an action or intend to do so. His explanation for this is, that here the “volitional impulse makes a path for the spasm”, which, however, is only the physiological paraphrase of the facts of the case. Psycho-analysis suspects here a psychical motivation: the activity of an unconscious contrary wish which puts itself in the way of the consciously wished act. This is indeed most striking in those patients of Erben who are prevented from going forward through the most violent attacks of shaking, but can carry out the much more difficult task of going backwards without trembling. Erben also here has a complicated physiological explanation ready, but forgets that the movement backwards, which removes the patient from the dangerous goal of the forward movement—and finally from the front line—does not need to be disturbed by any contrary wish. The remaining kinds of motor disturbances demand a similar interpretation, in particular the striking, uncontrollable running of many neurotics, so like the propulsion in paralysis agitans. These are the men who do not recover from the effect of the terror and are still always flying from dangers to which they were once exposed.
Many investigators, including non-psycho-analysts, came to the conclusion from these and similar observations, that these disturbances are not the direct effects of the trauma, but psychical reactions to it and act in the service of the instinct of self-preservation against the repetition of the unpleasant occurrence. We know that also the normal organism has at its disposal such protective measures. The symptoms of the terror, such as the immovable legs, the tremblings, the hesitating speech, seem to be useful automatisms; one is reminded by them of certain animals which simulate being dead when danger threatens. And if Bonhoeffer looks upon these traumatic disturbances as fixations of the means of expression of the terrible emotion which has been suffered, Nonne goes further and discovers that “the hysterical symptoms represent partly a reminiscence of inborn guard and defence mechanisms, the suppression of which in those individuals whom we call hysterical has not taken place in the normal degree or not at all”. According to Hamburger the most frequently occurring type of disturbances of standing, walking and speech associated with shaking tremors represents a “complex of ideas of feebleness, weakness, refusal and exhaustion”, and Gaupp sees in the same symptoms the lapse into infantile and puerile states of obvious helplessness. Some authors actually speak of the “fixation” in the traumatic posture of the body and innervation.