Regulation of spinal blood flow under physiological and pathological conditions.

three cases of spontaneous haemorrhage in the spinal canal, and the history of this condition, as it appears in the literature, was presented. In none of the cases did the haemorrhage result from an angioma; in two cases the bleeding was subdural and in one case extradural. The authors felt that slight trauma, which was usually held responsible for these episodes, was probably coincidental and that the origin, not only of extradural bleeding but also of subdural bleeding, was probably from a venous anomaly. One of their cases was due to a defect of blood coagulation due to anticoagulant therapy. In two cases spinal cord compression was severe and operation was undertaken later than would otherwise have been the case if the patient had initially been seen in a Department of Medical or Surgical Neurology.