The authors have carried out a clinical study of acute medico-surgical complications occuring in patients hospitalized following psychical stress, myocardial infarction, operatory shock and after the earthquake. In patients with duodenal ulcers and hyperacidity due to vagal neurogenic origins it was noted the presence of a sympatico-adrenergic constitutional background in 38% of the cases. By applying chemical sclerosis of the adrenals medullary the role of the medullary was demonstrated in the production of acute digestive lesions due to stress, as a result of standard electrical stimulus and of their influence on the bioelectrical reactivity of the brain, on the active learning behaviour by conditioned reaction and on the number of the circulating eosinophils following injections of A.C.T.H.