Assigning cause for sudden unexpected infant death.

We have reached a conundrum in assigning cause of death for sudden unexpected infant deaths. We summarize the discordant perspectives and approaches and how they have occurred, and recommend a pathway toward improved consistency. This lack of consistency affects pediatricians and other health care professionals, scientific investigators, medical examiners and coroners, law enforcement agencies, families, and support or advocacy groups. We recommend that an interdisciplinary international committee be organized to review current approaches for assigning cause of death, and to identify a consensus strategy for improving consistency. This effort will need to encompass intrinsic risk factors or infant vulnerability in addition to known environmental risk factors including unsafe sleep settings, and must be sufficiently flexible to accommodate a progressively expanding knowledge base.

Brain biomarkers for identifying excited delirium as a cause of sudden death.

Excited delirium (ED) syndrome is a serious medical condition associated with acute onset of agitated violent behavior that often culminates in a sudden unexplained death. While the contribution of restraint, struggle and the use of conductive energy devices (CED) to the cause and manner of death raise controversy, a CNS dysfunction of dopamine signaling may underlie the delirium and fatal autonomic dysfunction. We conducted a mortality review for a case series of ninety excited delirium deaths and present results on the association of a 2-protein biomarker signature. We conducted quantitative analyses of the dopamine transporter and heat shock protein 70 validated for specificity and degree of interindividual variation. Incident circumstances, force measures, autopsy and toxicology results were determined for all subjects. A majority of the victims in this case series tested positive for cocaine in blood and brain, although four had no licit or illicit drugs or alcohol measured at autopsy. Mean core body temperature where recorded was 40.7 degrees C. The expression of the heat shock protein HSPA1B transcript was elevated 1.8-4-fold in postmortem brain. The elevation of Hsp70 in autopsy brain specimens confirms that hyperthermia is an associated symptom and often a harbinger of death in these cases. Dopamine transporter levels were below the range of values measured in age-matched controls, providing pathologic evidence for increased risk of chaotic dopamine signaling in excited delirium. When combined with descriptions of the decedents' behavior prior to death, a 2-protein biomarker signature can serve as a reliable forensic tool for identifying the excited delirium syndrome at autopsy.