pH

pH measurement in brain tissue is a good indicator of premortem events in brain tissue and it signals limitations for post mortem investigations 1).

1)
Shrey DW, Griesbach GS, Giza CC. The pathophysiology of concussions in youth. Phys Med Rehabil Clin N Am. 2011 Nov;22(4):577-602, vii. doi: 10.1016/j.pmr.2011.08.002. Epub 2011 Sep 25. Review. PubMed PMID: 22050937; PubMed Central PMCID: PMC3211100.