We present the case of a 22-year-old asthmatic woman, who had undergone high-pressure servo-ventilation as part of the therapy of an otherwise untreatable asthmatic attack. Ventilation-pressures reached peaks of 80 mg H2O while under relaxation and sedation arterial blood pressure fell to 50/30 mm Hg. Treatment was complicated by pulmonary ruptures, pneumothorax and massive cutaneous emphysema. After successful completion of this treatment phase (day 14), the patient was allowed to regain consciousness and was found to be in a subtotal tetraplegic state: muscles of the neck, shoulders and left leg were slightly less atonic than others. Facial muscles, different qualities of sensitivity, intellectual functions and sense organs did not seem to be afflicted. Restitution of the tetraplegia was complete by day 50 of treatment, a neurological follow up six months after discharge from hospital showed no residual deficit. We hypothesize that the extreme ventilation-pressures together with the decrease of arterial blood-pressure have impaired the blood-flow in the system of the anterior spinal arteries. Together with concordant oedema this effected a localized dysfunction mainly of the ventral medullary areas corresponding to the functions of the anterior spino-cortical tract. Diagnostically we do not fully exclude steroid myopathia, but think in this case the cumulated steroid doses were too small and the course of remission indicates a localized haemodynamic lesion.