Biomarkers of Cerebral Damage in Fatal Hypothermia: Preliminary Results.

The identification of hypothermia as the cause of death remains challenging in forensic pathology because of unspecific radiological, morphological, and biochemical results. Hyperemia, edema, and petechial hemorrhages within the cerebral parenchyma were described in cases of death by hypothermia. On the other hand, the effect of low temperatures in the brain has been speculated to cause local injuries on a cellular level with potential occurrences of necrosis and inflammation. In the study herein described, endocan, alkaline phosphatase, neuron-specific enolase, S100 protein subunit B, glial fibrillary acidic protein, and C-reactive protein were measured in postmortem serum from femoral blood and cerebrospinal fluid in a series of hypothermia fatalities and control cases. The combination of data collected failed to identify a specific biochemical profile for death by hypothermia in postmortem serum and/or the cerebrospinal fluid, thus suggesting that an alternative panel of brain damage biomarkers indicative of diffuse hypoxic brain injury needs to be defined in hypothermia fatalities.

NICU admission hypothermia, chorioamnionitis, and cytokines.

OBJECTIVE: To determine whether neonatal intensive care unit (NICU) admission hypothermia is associated with an intrauterine inflammatory response. METHODS: We analyzed a cohort of 309 very low birthweight infants to determine relationships between admission hypothermia, chorioamnionitis, and serum and cerebrospinal fluid (CSF) interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α. RESULTS: Admission hypothermia <36°C occurred in 72% of patients <26 weeks and 44% of patients ≥26 weeks gestational age. NICU admission hypothermia was not associated with histologic chorioamnionitis or with elevated serum cytokine concentrations. CSF IL-6 concentrations ≥6.3 pg/mL were associated with admission hypothermia in infants <26 weeks' gestation. Clinical chorioamnionitis was associated with a lower risk of admission hypothermia, while cesarean section delivery was associated with increased risk. CONCLUSIONS: NICU admission hypothermia is common among preterm infants and is not associated with the fetal inflammatory response syndrome. Hypothermia is less common in the setting of clinical chorioamnionitis and more common in cesarean section deliveries, identifying two groups in whom extra attention to appropriate thermoregulation is warranted.

Evaluation of postmortem serum and cerebrospinal fluid levels of thyroid-stimulating hormone with special regard to fatal hypothermia.

The aim of the present study was to undertake, during routine forensic work, a comprehensive analysis of the serum and cerebrospinal fluid (CSF) levels of thyroid-stimulating hormone (TSH) and to examine hypophyseal TSH immunopositivity in relation to the cause of death, with particular regard to fatal hypothermia. Medicolegal autopsy cases (n=120; within 48 h postmortem; survival time, <24 h), including cases of blunt injury (n=9), sharp instrument injury (n=8), fire fatality (n=18), mechanical asphyxiation (n=10), drowning (n=21), poisoning (n=6), hypothermia (n=10), and acute ischemic heart disease (n=38), were examined. Serum and CSF TSH concentrations were measured using an electrochemiluminescence immunoassay. TSH immunoreactivity in adenohypophysis was quantitatively analyzed. Serum and CSF TSH levels were significantly lower in cases of hypothermia than in the other groups (p<0.05 and p<0.001, respectively). TSH immunopositivity in adenohypophysis was significantly lower in cases of hypothermia, but exhibited a large case-to-case variation for poisoning. These observations suggest that a decrease in serum and CSF TSH levels in hypothermia is related to hypothalamic adenohypophyseal dysfunction.