Brain-stem and adrenal abnormalities in the sudden-infant-death syndrome.

Fourteen of 28 sudden-infant-death syndrome (SIDS) victims had an abnormal proliferation of astroglial fibers in their brain stems and an enlarged mass of chromaffin cells in their adrenal medullas. Both of these abnormalities were associated with greater than normal muscle in the small pulmonary arteries, abnormal brown fat retention, and retained extramedullary erythropoiesis. These latter three findings are probably evidences of chronic alveolar hypoventilation and hypoxemia. The brain stem and adrenal abnormalities are probably also secondary to chronic hypoxemia.