For the differential diagnosis of psycho-neuroses from definite organic conditions, the most important element is the patient's previous history and a knowledge of the condition of the nervous system. Where this is known the diagnosis is comparatively easy, but when the patient is seen for the first time it may often be extremely difficult. It is, above all, important not to jump to conclusions, for every nervous specialist knows of cases in which the diagnosis was considered to be surely a neurosis, yet a fatal termination showed that a serious organic condition was at work. It must not be forgotten either that neurotic patients may develop serious organic disease in the midst of their neurotic symptoms and care must be taken not to miss the significance of special symptoms. When the patient is not well known, the presence of certain stigmata, as they have been called, enable the physician to recognize the probability that a neurotic condition is present. Patients who are subject to neuroses are likely to have certain areas of the skin surface and of the palpable mucous membranes more or less sensitive than normal. There are likely to be spots of hyperesthesia or hypesthesia or even complete anesthesia somewhere on the skin. These should be carefully looked for and in serious cases an examination of the whole skin surface should be made. Not infrequently anesthesia or a decided lack of sensitiveness to irritation will be found in the throat or in the nose. Occasionally the conjunctiva is much less sensitive than usual.

These used to be called hysterical stigmata. The word hysteria carries an innuendo of imaginativeness or occasionally of affection of the sexual organs that is unfortunate. It would be better, therefore, not to use the term in any way. The presence of these areas of hyperesthesia, hypesthesia and anesthesia indicates that association fibers are abnormally connected in the brain for the moment at least, and that as a consequence there is over-attention to certain portions of the body with lack of ordinary attention to others. This will account very readily for the occurrence of painful conditions in certain cases and palsies in others. When over-attention is paid, there may be a {591} hyperesthesia corresponding to that seen in the skin in any organ of the body. When, for any reason, there is a disturbance in a particular part, there may be a lack of motility due to nervous influences, just as there is a lack of sensation. In all of these cases the one essential element is to correct the nervous state through the mind as far as possible. Experience has shown that this can be done in nearly all cases. It must be the principal effort of the physician.