1. The effect of local instillation of hydrocortisone into the acutely swollen intervertebral disc was tested by combining the injection with a nucleogram.

2. The results, over a maximum follow-up period of eight months, are reported for the first sixty patients injected.

3. Nucleograms made of fifty-five patients demonstrated pathological lesions of the intervertebral discs. Thirty-seven patients (67 per cent) had rapid remission of symptoms after injection of hydrocortisone; eighteen (33 per cent) failed to respond.

4. Surgical exploration of the involved discs has been performed in sixteen of the eighteen failures and the discs in all cases demonstrated irreversible changes.

5. These results suggest a method of not only rapidly interrupting the course of an acute intervertebral disc herniation but also, more significantly, of demonstrating early in the course of the episode which discs are destined to require surgical intervention in spite of adequate conservative care. In this way, much of the morbidity and economic loss characteristic of these cases could probably be averted.

6. It is hoped that an investigation of the more fundamental causes of disc degeneration and of the mechanism of degeneration which underlie the empirical data presented here will help fill large gaps in our understanding of the pathogenesis and therapeutics of the degenerated and herniated intervertebral disc.