Lesions of the brain stem and related disorders of autonomous regulation systems have been the "Leitmotiv" of the scientific work in the Neurosurgical Department of the Giessen University under the leadership of the late Professor Hans Werner Pia. Some of the results have already been published in supplement volumes of Acta Neurochirurgica. The first one of these was Vol. 4 with the monograph written by H. W. Pia on "Die Schadigungen des Hirnstammes...