title: Effects of a small acute subdural hematoma following traumatic brain injury on neuromonitoring, brain swelling and histology in pigs.
abstract: An acute subdural hematoma (ASDH) induces pathomechanisms which worsen outcome after traumatic brain injury, even after a small hemorrhage. Synergistic effects of a small ASDH on brain damage are poorly understood, and were studied here using neuromonitoring for 10 h in an injury model of controlled cortical impact (CCI) and ASDH. Pigs (n = 32) were assigned to 4 groups: sham, CCI (2.5 m/s), ASDH (2 ml) and CCI + ASDH. Intracranial pressure was significantly increased above sham levels by all injuries with no difference between groups. CCI and ASDH reduced ptiO(2) by a maximum of 36 ± 9 and 26 ± 11%, respectively. The combination caused a 31 ± 11% drop. ASDH alone and in combination with CCI caused a significant elevation in extracellular glutamate, which remained increased longer for CCI + ASDH. The same two groups had significantly higher peak lactate levels compared to sham. Somatosensory evoked potential (SSEP) amplitude was persistently reduced by combined injury. These effects translated into significantly elevated brain water content and histological damage in all injury groups. Thus, combined injury had stronger effects on glutamate and SSEP when compared to CCI and ASDH, but no clear-cut synergistic effects of 2 ml ASDH on trauma were observed. We speculate that this was partially due to the CCI injury severity.
authors.affiliation: Institute for Neurosurgical Pathophysiology, University Medical Center of the Johannes Gutenberg-University of Mainz, Mainz, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Meissner
authors.forename: R
authors.initials: R
authors.lastname: Timaru-Kast
authors.forename: A
authors.initials: A
authors.lastname: Heimann
authors.forename: B
authors.initials: B
authors.lastname: Hoelper
authors.forename: O
authors.initials: O
authors.lastname: Kempski
authors.forename: B
authors.initials: B
authors.lastname: Alessandri
mesh_terms: D000818:Animals; D001929:Brain Edema / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D001930:Brain Injuries / Q000150:complications* / Q000473:pathology / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D004195:Disease Models, Animal; D005073:Evoked Potentials, Somatosensory; D018698:Glutamic Acid / Q000378:metabolism; D020199:Hematoma, Subdural, Acute / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D007427:Intracranial Pressure; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D008991:Monitoring, Physiologic; D034421:Sus scrofa
chemical_list: D019344:Lactic Acid; D018698:Glutamic Acid