Elevation of Postmortem Cerebrospinal Fluid Sodium and Chloride Levels Is a Potential Adjunct Test in the Diagnosis of Salt Water Drowning.

Postmortem vitreous humor biochemistry is a useful test in the diagnosis of salt water drowning (SWD). A significant limitation of vitreous humor is the potential effect of prolonged immersion. A recent animal study and case report suggested that cerebrospinal fluid biochemistry may be an alternative to vitreous because it is more resistant to the effects of immersion, given its protected anatomical location. This study compared postmortem cerebrospinal fluid sodium and chloride (PMCSC) levels collected via ventricular aspiration (PMCSC_V) and via lumbar puncture (PMCSC_L) in 13 SWD and 31 nonimmersion deaths. It showed a significant elevation in PMCSC levels in SWD deaths for both PMCSC_V and PMCSC_L (P < 0.05). The areas under the curve on the receiver operating characteristic curves for PMCSC_V and PMCSC_L were 0.73 and 0.83, respectively. The optimal cutoff for PMCSC_V was 216 mmol/L (sensitivity, 0.60; specificity, 0.72; likelihood ratio, 1.80; positive predictive value, 0.45) and for PMCSC_L was 241 mmol/L (sensitivity, 0.78; specificity, 0.73; likelihood ratio, 2.89; positive predictive value, 0.46). This study supports PMCSC levels as another biochemical test that can potentially aid in the diagnosis of SWD, particularly in cases where vitreous humor samples are unavailable or uninterpretable.

Neisseria meningitidis Isolated in Vitreous Humor in a 5-Month-Old Infant Death From Meningococcal Sepsis.

Diagnosing sepsis at postmortem is challenging. With respect to meningococcal sepsis, the postmortem microbiological identification of Neisseria meningitidis is nearly always due to true infection, including in cases of decomposition. Previous case series and case reports were able to isolate N. meningitidis in vitreous humor in adult deaths from meningococcal sepsis when blood and/or cerebrospinal fluid was unavailable. It was suggested that vitreous humor polymerase chain reaction (PCR) may be useful in the diagnosis of meningococcal sepsis. We describe a fatal case of meningococcal sepsis in a 5-month-old infant where N. meningitidis was detected in vitreous humor, cerebrospinal fluid, and blood through PCR. The presented case report gives further evidence in the potential use of vitreous PCR analysis in suspected meningococcal sepsis, particularly in the pediatric population.

Biochemical Differences Between Vitreous Humor and Cerebral Spinal Fluid in a Death From Diabetic Ketoacidosis.

Biochemical analysis of cerebrospinal fluid (CSF) and vitreous humor (VH) forms an important diagnostic ancillary test at autopsy. Cerebrospinal fluid can be sampled from the ventricular system (VA) and from lumbar puncture (LP), whereas VH can be sampled from the orbits. Biochemical electrolytes seem to vary between VH and CSF collected from different sites, but whether there is any difference in glucose and ß-hydroxybutyrate is unclear. We present a case report of a 21-year-old man who died of diabetic ketoacidosis confirmed at autopsy. Ventricular system, LP, and VH were biochemically analyzed and showed that glucose was highest in VH (41 mmol/L) and was 6 and 8 mmol/L higher than CSF in the LP and VA, respectively. ß-Hydroxybutyrate was also highest in VH (20 mmol/L) and was 5 and 6 mmol/L higher than LP and VA, respectively. Our findings suggest that postmortem CSF glucose and ß-hydroxybutyrate may not truly reflect that of VH and vary between CSF sampling sites.