A Perspective on Neuropathologic Findings in Victims of the Sudden Infant Death Syndrome: The Triple-Risk Model

TLDR

Neuropathologic studies in SIDS victims reveal underlying vulnerabilities that predispose infants to sudden death, yet the triple‑risk model allows for a common pathway where multiple stressors converge during a critical period. The authors propose a triple‑risk model linking latent infant vulnerability to sudden death. The model posits that sudden death occurs only when an infant’s latent vulnerability coincides with a critical developmental period in homeostatic control and an exogenous stressor. The model suggests that disorders such as arcuate nucleus hypoplasia and subtle hypomyelination can render infants vulnerable during the critical period.

Abstract

Neuropathologic studies in SIDS victims support the concept that they are not entirely 'normal' prior to death, but rather possess underlying vulnerabilities which put them at risk for sudden death. This concept 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, and (3) an exogenous stressor(s). An infant will die of SIDS only if he/she possesses all three factors; the infant's vulnerability lies latent until he/she enters the critical period and is subject to an exogenous 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 brains (arcuate nucleus hypoplasia and subtle hypomyelination). Nevertheless, the triple-risk model does not preclude the possibility that the majority of SIDS deaths will be explained by a single common pathway upon which multiple stressors impinge to produce sudden death during the critical period.