The quadrant-syndrome (Q.S.) is a functional disturbance of the vegetative system, characterized by the distribution of subjective and objective lesions to a quarter of the body (quadrant). The neurological aspect of the Q.S. varies so much in character, that it may mistakenly be considered to be psychogenic in origin. All qualities of peripheral nerve function can be affected singly or collectively and in varying degree. The duration of illness cannot be predicted; it may last from some weeks up to more than 10 years. The patients age seems to play some role in the duration of the syndrom. On account of symptomatological and pathogenetical similarities with the dystrophy of Sudeck and the causalgic state, it appears that the Q.S. would be observed more frequently, if its characteristic principle of distribution to a quarter of the body is taken into consideration. Out of the many possible causes of this syndrom the common lesions of the extremities are pointed out. These peripheral lesions act as focus, which affects a specially predisposed central vegetative nervous system. A case report is given of an 18 year-old girl suffering from a median nerve compression in the elbow region (pronator teres syndrom) and developing a Q.S. with complete anaesthesia and analgesia. Six weeks after surgical decompression of the median nerve, she was free of symptoms and remained free of symptoms after a follow up control six months later. Besides sanitation of the peripheral focus, sympathectomy is critically discussed, and the possibility of preventive treatment in common lesions of the extremities is ventilated.