The influence of individual characteristics of the research subject on the electrical conductivity parameters of cerebrospinal fluid

Background: The analysis of cerebrospinal fluid has been repeatedly recognized in the scientific literature as a promising forensic tool for addressing critical questions related to fatal traumatic brain injuries, such as determining its age and assessing its severity. Conductometry has long been used in medicine as an objective method for studying biological samples. However, the influence of individual characteristics of the object on the conductometric properties of cerebrospinal fluid remains insufficiently studied.

Aim: To investigate the electrical conductivity properties of cerebrospinal fluid in deceased individuals who died from traumatic brain injuries, considering individual characteristics of autopsy material to substantiate the poteвntial of conductometric analysis as a research tool for determining the time of traumatic impact leading to injury formation.

Materials and methods: The experimental conductometric study was carried out on cerebrospinal fluid samples from 124 corps of persons aged 17 to 93 years who had died from traumatic brain injury and its consequences (with post-injury intervals ranging from 0 to 10 days). The electrical conductivity was measured using the AKIP RLC 6109 device, with an error of 0.1%, at frequencies of 0.1 kHz, 1 kHz, and 10 kHz. The study considered the subject’s sex, age, postmortem interval, presence of ethanol in the blood at the time of death, and the ethanol concentration.

Results: The subject’s sex was found to be a significant factor influencing the value of electrical conductivity of cerebrospinal fluid. In contrast, the deceased’s chronological age did not significantly affect the measured cerebrospinal fluid properties, nor did the postmortem interval within the first 24 hours. The absolute ethanol concentration (in ‰) had no substantial effect on cerebrospinal fluid conductivity. However, the mere presence of ethanol in the sample significantly altered its ability to conduct electrical current.

Conclusion: The influence of the above factors must be considered when developing a conductometric method for studying cerebrospinal fluid in those deceased from traumatic brain injury, as it can impact the assessment of injury severity and the age of injury.