Biochemical changes in the injured brain

Table 1 Serum and cerebrospinal fluid biomarkers of cerebral injury

	Structure effected	Findings in brain injury
		Cerebro spinal fluid	Blood/serum
Tau protein	Axon	Levels peak 4-8 d after injury[111,112]	Elevated levels in hypoxic injury[113,114]
Myelin basic protein	Axon	Precise measurement difficult[115]	Elevated levels in brain injury[116]
γ-enolase	Neuron	Confounded by blood contaminated CSF[117]	Serum levels are very sensitive to lysis of RBC in blood contaminated CSF[117], elevated levels in brain injury[116]
S-100 β	Astrolglial cells	Elevated levels but less sensitive[108]	Confounded by release from extracerebral tissue[118]
GFAP	Astroglial cells	Elevated levels but less sensitive[107,108]	Serum levels correlate with changes in brain imaging[119], no extracerebral sources detected[120]
UCH-L1	Neuron	NA	Only one pilot study[98]

GFAP: Glial fibrillary acidic protein; UCH-L1: Ubiquitin c terminal hydrolase; NA: Not available; CSF: Cerebrospinal fluid; RBC: Red blood cell.