title: Early identification of secondary brain damage in subarachnoid hemorrhage: a role for glial fibrillary acidic protein.
abstract: Secondary ischaemic deficit adversely affects outcome in patients with subarachnoid hemorrhage (SAH). Astrocytes are vulnerable to ischemia, releasing glial fibrillary acidic protein (GFAP) when challenged. In this study, we followed nine patients with SAH who underwent extra-ventricular drainage for the management of secondary hydrocephalus. Cerebrospinal fluid (CSF) was collected daily for up to 14 days. CSF GFAP was quantified using a standard ELISA. In the patients, we found that the CSF GFAP values were pathologically elevated in 83/89 (93%) of the CSF samples. The levels were highest on day 1 (median = 47.64 ng/mL) and decreased to 11.19 ng/mL on day 3, leveling out at approximately 1 ng/mL after 10 days. In non-survivors, a secondary rise of GFAP levels became significant during the high-risk period for vasospasm, with median levels of 21.76 ng/mL compared to 2.62 ng/mL in the survivors (p = 0.037) on day 6. This study suggests that CSF GFAP levels are of prognostic value in SAH. Additionally, the difference in the slope of GFAP levels between survivors (rapid wash-out) and non-survivors (secondary peaks) may allow difierentiation between primary brain injury from secondary brain damage due to delayed cerebral ischaemia.
authors.affiliation: Department of Neuroimmunology, Institute of Neurology, University College London, London, United Kingdom. a.petzold@ion.ucl.ac.uk
authors.forename: Axel
authors.initials: A
authors.lastname: Petzold
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Keir
authors.forename: Mary
authors.initials: M
authors.lastname: Kerr
authors.forename: Andrew
authors.initials: A
authors.lastname: Kay
authors.forename: Neil
authors.initials: N
authors.lastname: Kitchen
authors.forename: Martin
authors.initials: M
authors.lastname: Smith
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Thompson
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000134:cerebrospinal fluid* / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000134:cerebrospinal fluid* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013345:Subarachnoid Hemorrhage / Q000134:cerebrospinal fluid* / Q000150:complications / Q000401:mortality; D017741:Survivors; D013997:Time Factors
chemical_list: D005904:Glial Fibrillary Acidic Protein