title: Neuro-inflammatory Sequelae of Minimal Trauma in the Non-traumatized Human Brain: A Microdialysis Study.
abstract: Cytokine measurement directly from the brain parenchyma by means of microdialysis has documented the activation of certain proceduresin vivo, after brain trauma in humans. However, the intercalation of the micro-catheter insertion with the phenomena triggered by the head trauma renders the assessment of the findings problematic. The present study attempts to elucidate the pure effect of minimal trauma, represented by the insertion of the micro-catheter, on the non-traumatized human brain. Microdialysis catheters were implanted in 12 patients with drug-resistant epilepsy, and subjected to invasive electroencephalography with intracranial electrodes. Samples were collected during the first 5 days of monitoring. The dialysate was analyzed using bead flow cytometry, and the concentrations of interleukin (IL)-1, IL-6, IL-8, IL-10, IL-12, and tumor necrosis factor-α (TNF-α) were measured. The levels of IL-1 and IL-8 were found to be raised until 48 h post-implantation, and thereafter they reached a plateau of presumably baseline values. The temporal profile of the IL-6 variation was different, with the increase being much more prolonged, as its concentration had not returned to baseline levels at the fifth day post-insertion. TNF-α was found to be significantly raised only 2 h after implantation. IL-10 and IL-12 did not have any significant response to micro-trauma. These findings imply that the reaction of the neuro-inflammatory mechanisms of the brain exist even after minimal trauma, and is unexpectedly intense for IL-6. Questions may arise regarding the objectivity of findings attributed by some studies to inflammatory perturbation after head injury.
authors.affiliation: Department of Neurosurgery, Evaggelismos Hospital, University of Athens, Athens, Greece.
authors.forename: Triantafyllos
authors.initials: T
authors.lastname: Bouras
authors.affiliation: Department of Neurosurgery, Evaggelismos Hospital, University of Athens, Athens, Greece.
authors.forename: Stergios-Sylianos
authors.initials: SS
authors.lastname: Gatzonis
authors.affiliation: Department of Neurosurgery, Geniko Kratiko Hospital, Holargos, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Georgakoulias
authors.affiliation: Laboratory of Biochemistry, Evaggelismos Hospital, University of Athens, Athens, Greece.
authors.forename: Marilena
authors.initials: M
authors.lastname: Karatza
authors.affiliation: Department of Neurosurgery, Evaggelismos Hospital, University of Athens, Athens, Greece.
authors.forename: Anna
authors.initials: A
authors.lastname: Siatouni
authors.affiliation: Department of Neurosurgery, Evaggelismos Hospital, University of Athens, Athens, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Stranjalis
authors.affiliation: Department of Neurosurgery, Evaggelismos Hospital, University of Athens, Athens, Greece.
authors.forename: Efstathios
authors.initials: E
authors.lastname: Boviatsis
authors.affiliation: Laboratory of Biochemistry, Evaggelismos Hospital, University of Athens, Athens, Greece.
authors.forename: Spyridoula
authors.initials: S
authors.lastname: Vasileiou
authors.affiliation: Department of Neurosurgery, Evaggelismos Hospital, University of Athens, Athens, Greece.
authors.forename: Damianos E
authors.initials: DE
authors.lastname: Sakas
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D000069279:Drug Resistant Epilepsy / Q000378:metabolism* / Q000601:surgery; D000069280:Electrocorticography / Q000009:adverse effects* / Q000295:instrumentation; D004567:Electrodes, Implanted / Q000009:adverse effects*; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D008297:Male; D017551:Microdialysis / Q000379:methods*; D013997:Time Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators