A PERSPECTIVE ON NEUROPATHOLOGIC FINDINGS IN VICTIMS OF THE SUDDEN-INFANT-DEATH-SYNDROME - THE TRIPLE-RISK MODEL

Neuropathologic studies in SIDS victims support the concept that they are not entirely 'normal' prior to death, but rather possess underlyin g vulnerabilities which put them at risk for sudden death. This concep t forms a key link in a triple-risk model for the pathogenesis of SIDS proposed by us. According to this model, sudden death in SIDS results from the intersection of three overlapping factors: (1) a vulnerable infant; (2) a critical developmental period in homeostatic control, an d (3) an exogenous stressor(s). An infant will die of SIDS only if he/ she possesses all three factors; the infant's vulnerability lies laten t until he/she enters the critical period and is subject to an exogeno us stressor. According to this model, heterogeneous disorders may make the infant vulnerable to sudden death during the critical period, as potentially exemplified by two previously reported lesions in SIDS bra ins (arcuate nucleus hypoplasia and subtle hypomyelination). Neverthel ess, the triple-risk model does not preclude the possibility that the majority of SIDS deaths will be explained by a single common pathway u pon which multiple stressors impinge to produce sudden death during th e critical period.