[Central regulation of breathing in idiopathic scoliosis (author's transl)]

Idiopathic scoliosis is in nearly 80% associated with an EEG deviating from a normal pattern. Therefore a possible cerebral dysfunction as one of the etiologic factors in the development of idiopathic scoliosis is discussed. In consequence, we studied the central respiratory regulation in 26 patients with idiopathic scoliosis by means of CO2 response with the CO2 rebreathing technique, also vital capacity (VC), maximal voluntary ventilation (MVV), respiratory minute volume at 50, 60 and 70 mm Hg arterial pCO2 and EEG. The CO2-index (1/min/mm Hg CO2) was significantly lower in patients with idiopathic scoliosis (0.92 +/- 0.43) than in normals (1.5 +/- 0.3). The decrease of CO2-index is mainly associated with the smaller VC of the patients (76 +/- 26% of predicted). There is no sign of an additional influence of cerebral dysfunction. Patients with idiopathic scoliosis are able to utilize 70% of the individual breathing reserve like normals when stimulated with CO2. The EEG and the VC show a negative correlation. This may possibly be due to a compensation of the preexisting cerebral dysfunction. VC however decreases during the natural course of disease. No significant correlation could be found between CO2-index and the angle of scoliosis, indicating the absence of a causal relation between the degree of deformation itself and the function of the center of respiratory regulation.