CATECHOLAMINE NEURONS ALTERATION IN THE BRAIN-STEM OF SUDDEN-INFANT-DEATH-SYNDROME VICTIMS

Background. Sudden infant death syndrome (SIDS) is a leading cause of postneonatal infant death. The pathogenesis of sudden death is still u nknown, but an abnormality in the central nervous regulation of breath ing during sleep has been suggested. Objective. The aim of study is to confirm the brainstem disorder of SIDS victims. In order to do this, it is necessary to investigate the alterations of brain neurotransmitt er systems thought to be involved in respiratory control. Design. Neur opathologic study performed on the brainstem of SIDS victims. Subject/ Methods. The disorders of catecholaminergic systems in 22 SIDS victims were examined on the substantia nigra in the midbrain, locus coeruleu s in the pens, vagal nuclei, and area reticularis superficialis ventro lateralis with the immunohistochemical method. Immunoperoxidase staini ng was performed with the antityrosine hydroxylase (TH) and the glial fibrillary acidic protein antibodies. Immunoreactivity was compared wi th 13 age-matched control infants. For statistical analysis, the chi(2 ) test and the Student's t test were performed. Results. The main find ing was diminished TH immunoreactivity in the vagal nuclei and area re ticularis superficialis ventrolateralis of SIDS victims, suggesting th at adrenaline and noradrenaline neurons are altered in SIDS. In additi on, this decrease in TH was closely correlated with brainstem gliosis. Conclusion. These catecholaminergic changes may be caused by chronic hypoxia or ischemia, and also may underlie alterations in respiratory and cardiovascular control in sleep.