S100B protein (S100B) has been described as a marker of brain injury. Various cytokines also increase in the cerebrospinal fluid (CSF) of patients with severe traumatic brain injury (TBI). Thus, we investigated early changes in the concentrations of CSF S100B and various cytokines after TBI and evaluated the relations of both S100B and cytokines to intracranial pressure (ICP) and prognosis. Twenty-three patients with severe TBI and a Glasgow Coma Scale score of 8 or less on admission were included in this study. CSF and serum samples were obtained on admission and at 6, 12, 24, 48, 72, and 96 h after injury. CSF concentrations of S100B and CSF and serum concentrations of five cytokines (IL-1beta, TNF-alpha, IL-6, IL-8, and IL-10) were measured and compared. The CSF S100B concentration was increased for 6 h after injury and decreased thereafter. The CSF concentrations of IL-6 and IL-8 peaked within 6 h after injury; other cytokines (IL-1beta, TNF-alpha, and IL-10) were elevated for 24 h after injury and gradually decreased thereafter. Peak CSF S100B concentrations correlated significantly with ICP determined at the time CSF samples were taken (r = 0.729, P < 0.0001). For the cytokines investigated, only the peak CSF IL-1beta concentration correlated significantly and positively with the peak CSF S100B concentration (r = 0.397, P < 0.005). Peak CSF concentrations of S100B (1649 +/- 415 microg/L, mean +/- SEM) and IL-1beta (16.5 +/- 3.3 pg/mL) in the 6 patients with high ICP were significantly higher than those (233 +/- 67 microg/L, 7.6 +/- 1.7 pg/mL, respectively) in the 17 patients with low ICP (P < 0.05). The CSF S100B concentration (1231 +/- 378 microg/L) in eight patients with an unfavorable outcome was significantly higher than that (267 +/- 108 microg/L) in 15 patients with a favorable outcome (P < 0.05). The CSF IL-1beta concentration (14.8 +/- 3.4 pg/mL) in eight patients with an unfavorable outcome tended to be higher than that (7.3 +/- 1.5 pg/mL) in 15 patients with a favorable outcome (P = 0.057). CSF concentrations of S100B and cytokines peak within 24 h after severe TBI and decrease gradually thereafter. CSF S100B and IL-1beta may be useful as predictors of outcome in cases of severe TBI.

In our previous study of patients with early-phase severe traumatic brain injury (TBI), the anti-inflammatory interleukin (IL)-10 concentration was lower in cerebrospinal fluid (CSF) than in serum, whereas proinflammatory IL-1beta and tumor necrosis factor (TNF)-alpha concentrations were higher in CSF than in serum. To clarify the influence of additional injury on this disproportion between proinflammatory and anti-inflammatory mediators, we compared their CSF and serum concentrations in patients with severe TBI with and without additional injury. All 35 study patients (18 with and 17 without additional injury) had a Glasgow Coma Scale score of 8 or less upon admission. With the exception of additional injury, clinical characteristics did not differ significantly between groups. CSF and serum concentrations of two proinflammatory mediators (IL-1beta and TNF-alpha,) and three anti-inflammatory mediators (IL-1 receptor antagonist [IL-1ra], soluble TNF receptor-I [sTNFr-I], and IL-10) were measured and compared at 6 h after injury. CSF concentrations of proinflammatory mediators were much higher than the corresponding serum concentrations in both patient groups (P < 0.001). In contrast, serum concentrations of anti-inflammatory mediators were much higher than the paired CSF concentrations in patients with additional injury (P < 0.001), but serum concentrations were lower than or equal to the corresponding CSF concentrations in patients without additional injury. CSF concentrations of IL-1beta, IL-1ra, sTNFr-I, and IL-10 were significantly higher (P < 0.01 for all) in patients with high intracranial pressure (ICP; n = 11) than in patients with low ICP (n = 24), and were also significantly higher (P < 0.05 for all) in patients with an unfavorable outcome (n = 14) than in patients with a favorable outcome (n = 21). These findings indicate that increased serum concentrations of anti-inflammatory mediators after severe TBI are mainly due to additional extracranial injury. We conclude that anti-inflammatory mediators in CSF may be useful indicators of the severity of brain damage in terms of ICP as well as overall prognosis of patients with severe TBI.

Mild hypothermia should not be used for the treatment of severely head injured patients with low ICP because this therapy conveys no advantage over normothermia in such patients.

The authors recommend normothermia therapy for the treatment of severely head injured patients in whom ICP can be maintained at lower than 20 mm Hg by using conventional therapies, because mild hypothermia therapy does not convey any advantage over normothermia therapy in such patients.

We studied cerebral blood flow (CBF) in the transition from the acute to the chronic phase of severe head injury in order to determine patterns of change in relation to neurological outcome. We measured CBF with stable xenon-enhanced computed tomography (Xe-CT) in 20 consecutive patients at 1, 2, 3, 4, and 6 weeks after severe head injury, and analyzed the relation between the pattern of change in CBF and neurological outcome at 6 months after injury. CBF values were significantly lower in the brain-injured patients than in 14 healthy volunteers, except at 3 weeks after injury, when CBF increased in the patients to a value that did not differ significantly from that in the normal volunteers. We therefore focused on the change in CBF at 3 weeks after injury. We separated the 20 brain-injured patients into two subgroups, of which the first (subgroup A) consisted of nine patients whose CBF had returned to normal by week 3 post-injury, while the second (subgroup B) consisted of 11 patients whose CBF was subnormal at week 3 post-injury. CBF was significantly higher in subgroup A than in subgroup B at 2 weeks post-injury (p < 0.05). CBF in subgroup B remained significantly lower than that in subgroup A throughout the study period. At 6 months post-injury, subgroup A had a significantly better neurological outcome than did subgroup B (p < 0.05). We conclude that patients whose CBF returns to normal at 2-3 weeks following severe traumatic brain injury after being abnormally low in the acute phase of injury can be expected to achieve a good neurological outcome.

Recent experimental studies have revealed that traumatic brain injury as well as ischemic brain injury can cause chronic progressive neuronal damage. In the present study, we demonstrate previously unreported delayed cerebral atrophy on computerized tomography (CT) scans in severely head-injured patients. Seventeen severely head-injured patients who required mild hypothermia to control intracranial hypertension after the failure of conventional therapies were retrospectively analyzed. All 17 patients survived more than 1 year. Delayed neuronal loss (DNL) was observed in only eight of the 17 patients. Eight patients with DNL required longer durations of mild hypothermia to control intracranial hypertension than nine patients without DNL. Six of these eight patients with DNL achieved functional recovery despite progressive atrophic changes demonstrated on CT scans. On CT scans, DNL was characterized by (1) the sudden appearance at several months postinjury of a low-density area in the hemisphere ipsilateral to the injury; (2) the preservation of essential cortical structure although related white matter structures showed severe atrophic changes; and (3) no spread of the low-density area to the contiguous territory of the other main cerebral artery. It is concluded that focal primary injury to underlying brain, if severe enough, can result in delayed hemispheric atrophy.

No abstract

The potential for tissue hypoxia is likely to be increased during hypothermia when the circulation becomes unstable and oxygen delivery decreases.