Estimation of time since death from CSF electrolyte concentration in Bhopal region of central India.

Estimation of time since death from sodium and potassium ion concentration levels in CSF (cerebrospinal fluid) was carried out in 100 medico legal autopsies with known time of death in the department of Forensic medicine, Gandhi Medical College in Bhopal region of Central India. CSF was aspirated from lateral ventricles after opening the skull and dura, and concentration of these ions were estimated by flame photometry. Results revealed a significant correlation of sodium and potassium ions in CSF up to 25 h of time since death, with average per hour rise of 1.21 meq/h for potassium and fall of 1.115 meq/h for sodium ions. A useful relationship between sodium potassium ion ratio and PMI (post-mortem interval) was also elicited. The study concludes that changes in CSF electrolyte is a significant parameter to estimate time since death.