Predictors of pulmonary failure following severe trauma: a trauma registry-based analysis.

BACKGROUND: The incidence of pulmonary failure in trauma patients is considered to be influenced by several factors such as liver injury. We intended to assess the association of various potential predictors of pulmonary failure following thoracic trauma and liver injury. METHODS: Records of 12,585 trauma patients documented in the TraumaRegister DGU® of the German Trauma Society were analyzed regarding the potential impact of concomitant liver injury on the incidence of pulmonary failure using uni- and multivariate analyses. Pulmonary failure was defined as pulmonary failure of ≥ 3 SOFA-score points for at least two days. Patients were subdivided according to their injury pattern into four groups: group 1: AIS thorax < 3; AIS liver < 3; group 2: AIS thorax ≥ 3; AIS liver < 3; group 3: AIS thorax < 3; AIS liver ≥ 3 and group 4: AIS thorax ≥ 3; AIS liver ≥ 3. RESULTS: Overall, 2643 (21%) developed pulmonary failure, 12% (n= 642) in group 1, 26% (n= 697) in group 2, 16% (n= 30) in group 3, and 36% (n= 188) in group 4. Factors independently associated with pulmonary failure included relevant lung injury, pre-existing medical conditions (PMC), sex, transfusion of more than 10 units of packed red blood cells (PRBC), Glasgow Coma Scale (GCS) ≤ 8, and the ISS. However, liver injury was not associated with an increased risk of pulmonary failure following severe trauma in our setting. CONCLUSIONS: Specific factors, but not liver injury, were associated with an increased risk of pulmonary failure following trauma. Trauma surgeons should be aware of these factors for optimized intensive care treatment.

Delayed neuromotor recovery and increased memory acquisition dysfunction following experimental brain trauma in mice lacking the DNA repair gene XPA.

OBJECT: This study investigates the outcome after traumatic brain injury (TBI) in mice lacking the essential DNA repair gene xeroderma pigmentosum group A (XPA). As damage to DNA has been implicated in neuronal cell death in various models, the authors sought to elucidate whether the absence of an essential DNA repair factor would affect the outcome of TBI in an experimental setting. METHODS: Thirty-seven adult mice of either wild-type (n = 18) or XPA-deficient ("knock-out" [n = 19]) genotype were subjected to controlled cortical impact experimental brain trauma, which produced a focal brain injury. Sham-injured mice of both genotypes were used as controls (9 in each group). The mice were subjected to neurobehavoral tests evaluating learning/acquisition (Morris water maze) and motor dysfunction (Rotarod and composite neuroscore test), pre- and postinjury up to 4 weeks. The mice were killed after 1 or 4 weeks, and cortical lesion volume, as well as hippocampal and thalamic cell loss, was evaluated. Hippocampal staining with doublecortin antibody was used to evaluate neurogenesis after the insult. RESULTS: Brain-injured XPA(-/-) mice exhibited delayed recovery from impairment in neurological motor function, as well as pronounced cognitive dysfunction in a spatial learning task (Morris water maze), compared with injured XPA(+/+) mice (p < 0.05). No differences in cortical lesion volume, hippocampal damage, or thalamic cell loss were detected between XPA(+/+) and XPA(-/-) mice after brain injury. Also, no difference in the number of cells stained with doublecortin in the hippocampus was detected. CONCLUSIONS: The authors' results suggest that lack of the DNA repair factor XPA may delay neurobehavioral recovery after TBI, although they do not support the notion that this DNA repair deficiency results in increased cell or tissue death in the posttraumatic brain.

Outcome after operative treatment of Vancouver type B1 and C periprosthetic femoral fractures: open reduction and internal fixation versus revision arthroplasty.

INTRODUCTION: The rate of periprosthetic femoral fractures after hip arthroplasty is rising and the estimated current lifetime incidence is 0.4-2.1%. While most authors recommend revision arthroplasty in patients with loose femoral shaft components, treatment options for patients with stable stem are not fully elucidated. METHOD: Against this background we performed a retrospective chart analysis with clinical follow-up examination of 32 cases that sustained a Vancouver type B1 or C periprosthetic fracture (stable stem). PATIENTS: Overall 16 cases were treated by open reduction and internal fixation (ORIF) by plate osteosynthesis and 16 cases by revision arthroplasty (RA). Both groups were comparable regarding age, gender, follow-up time interval, time interval from primary hip arthroplasty to fracture and rate of cemented femoral components, but more type C fractures were treated by ORIF. RESULTS: Functional outcome expressed by the median timed "Up and Go" test did not differ significantly (30 s ORIF vs. 24 s RA, P = 0.19). However, by comparable systemic complications surgery-related complications were significantly more frequent in plate osteosynthesis (ORIF n = 10 vs. RA n = 3, P = 0.03). Based on our results, further studies, preferable via a multicenter approach, should focus on identifying patients that benefit from ORIF in periprosthetic fractures. A misinterpretation of type B2 fractures with loose implant as type B1 fractures may cause implant failure in case of ORIF. CONCLUSION: The use of angular stable implants, additional cable wires or bone enhancing means is recommended.

Prehospital and Early Clinical Care of Infants, Children, and Teenagers Compared to an Adult Cohort : Analysis of 2,961 Children in Comparison to 21,435 Adult Patients from the Trauma Registry of DGU in a 15-Year Period.

BACKGROUND: Although the incidence of pediatric patients in emergency services is as low as 5-10%, trauma remains one of the leading causes of death during childhood. Only a few reports exist about the quality of the initial treatment of pediatric trauma patients. Therefore, we tested the hypothesis of whether prehospital treatment and emergency management in pediatric trauma patients is similar to the treatment that is provided for adult patients. MATERIALS AND METHODS: We performed a retrospective data analysis of the German Trauma Registry of the DGU from January 1993 to December 2007. Exclusion criteria were missing information about injury severity and/or age and patients older than 50 years. All pediatric patients were subdivided into five groups (infants 0-1 year, toddlers 2-5 years, children 6-9 years, pupils 10-13 years, teenagers 14-17 years) with regard to their age and were compared with the adult cohort (18-50 years). From 24,396 patients, 2,961 were below 18 years of age, thus, about 12% of the whole population of injured patients below the age of 50 years. RESULTS: 66.4% of infants sustained relevant head injuries (Abbreviated Injury Scale [AIS] ≥3), and this rate declined with increasing age. The mean Injury Severity Score (ISS) increased from 21.0 (±11.6) in the group of infants to 26.7 (±13.9) in the adult cohort. In all groups, the majority of patients were male. The injury pattern differed according to age, with predominant traumatic brain injury (TBI) in infants. During the preclinical treatment, infants were less often intubated and this was contrasted by a higher rate of cardiopulmonary resuscitation in this group (infants 16.2%, toddlers 6.8%, adults 3.1%). Diagnostic multislice computed tomography (CT) examination was less often performed in infants as compared to the other groups (infants 57.1%, toddlers 77.2%, adults 77.8%). Mortality and quality indicators such as timelines show no significant differences between children and adults. CONCLUSION: We observed typical age-dependent differences regarding the injury pattern and severity and differences referring to the preclinical and initial treatment. With respect to the high rate of serious TBI in the infants and toddlers age groups, a more focused education and training of emergency physicians and paramedics should be considered.

Periprosthetic humeral fractures after shoulder arthroplasty: operative management and functional outcome.

BACKGROUND: Currently, little information is available on functional outcome of periprosthetic humeral fractures after shoulder arthroplasty. This investigation aimed to evaluate functional and radiological outcome and patients' satisfaction following this type of injury treated by open reduction and internal fixation. METHODS: Retrospective chart analysis of patients treated at two level-I trauma centers. Patients were examined clinically and radiologically. Additionally, functional outcome was assessed using the established DASH-questionnaire and standardized examination for calculation of the Constant score. RESULTS: Five out of six patients showed complete fracture consolidation with satisfying functional results (mean follow up time 62 weeks). One patient showed major complications with poor outcome. DASH and Constant scores were comparable to those described after primary shoulder arthroplasty. CONCLUSIONS: Periprosthetic humeral fractures after shoulder arthroplasty can be treated by angular stable plating with low complication rates and acceptable results.

Early versus late onset of multiple organ failure is associated with differing patterns of plasma cytokine biomarker expression and outcome after severe trauma.

Although multiple organ failure (MOF) remains the leading cause of death after trauma, the pathogenic cellular and molecular mechanisms underlying MOF are poorly understood. In addition to proinflammatory and anti-inflammatory mediator cascades, the temporal onset of MOF has generated recent interest because the organ systems involved into MOF seem to deteriorate in a time-dependent fashion after trauma. We therefore investigated the temporal course of MOF in traumatized human patients and evaluated and compared the distribution patterns of cytokine expression, including interleukin (IL) 6, IL-8, IL-10, and the soluble tumor necrosis factor-[alpha] receptors sTNF-R p55 and sTNF-R p75 in early-onset versus late-onset MOF. In addition, we analyzed the predictive value of cytokine biomarkers of MOF and lethal outcome. In a prospective observational cohort study conducted at three trauma centers, all patients (n = 352) admitted to two level 1 trauma centers in Germany were enrolled in the study based on the following inclusion criteria: severe traumatic brain injury (TBI) with a Glasgow Coma Scale (GCS) score of 8 or lower and/or distinct changes in cranial computed tomography and/or multiple injuries (MT) to the body (at least two regions had Abbreviated Injury Scale score of 3 or higher). The incidence of MOF was evaluated using the modified Goris-MOF score. The temporal onset of MOF was divided into early-onset MOF (EMOF, developing on days 0-3), late-onset MOF (LMOF, developing on days 4-10), combined early-onset and late-onset MOF (CMOF), and patients never showing signs of MOF during the observation period. In addition, the levels of the serum cytokine markers IL-6, IL-8, IL-10, sTNF-R p55, and sTNF-R p75 were analyzed at specific posttraumatic time points using established enzyme-linked immunosorbent assay techniques. A total of 352 patients (274 men and 78 women; TBI, 101; TBI + MT, 125; MT, 126) were enrolled into the study. Patients assigned to the EMOF group showed specific disruption of pulmonary and cardiocirculatory function, whereas LMOF was significantly associated with hepatic failure. The patients without signs of MOF and the EMOF patients had the same risk of lethal outcome (8.2% vs. 7.5%); LMOF and CMOF were found to be associated with a 3- to 4-fold increase in mortality (38.5% vs. 30.6%, respectively). Analysis of cytokine serum biomarkers revealed that patients with LMOF showed a biphasic elevation of IL-6 and significantly higher sTNF-R concentrations than did all other subgroups (P < 0.001). In addition, the initial values (days 0-1) of sTNF-R p55 and sTNF-R p75 expression levels had a good predictive capacity for the development of LMOF (p55, 0.75; p75, 0.72); values greater than 0.65 were accepted to have a predictive capacity. These results demonstrate that mortality differs significantly between the development of EMOF and LMOF after traumatic injury. Our results also suggest that serum cytokine measurements may be important early biochemical markers for predicting the development of delayed MOF.

Changes in cortical and subcortical energy metabolism after repetitive and single controlled cortical impact injury in the mouse.

In the present investigation we examined regional ATP, glucose, and lactate content in the cortical and subcortical region, in a mouse model of controlled cortcal impact (CCI) injury. In serial tissue sections, bioluminescence imaging of ATP, glucose, and lactate was performed 1 h after a single CCI injury or sham surgery and 15 min, 1, 24, and 48 h after the induction of a second CCI injury 24 h later or sham surgery. Bioluminescence images were analyzed by computer-assisted densitometry at the lesion site, at the contralateral site, and in a subcortical region. After repetitive CCI injury, the cortical ATP content decreased bilaterally at 15 min and 1 h, and reached a significant minimum at 24 h, as compared with sham. At 48 h the ATP content bilaterally reached base level again. No significant changes in ATP were found in the subcortical region. After repetitive CCI injury, the lactate content increased bilaterally, reached a significant level at 15 min at the trauma site, and bilaterally reached a significant maximum at 1 h. Thereafter, lactate content decreased below base level without reaching significance and reached baseline again at 48 h. In the ipsilateral subcortical region, lactate content increased transiently above the baseline at 1 h and decreased to a significant minimum at 24 and 48 h. No significant changes were found in the contralateral subcortical area. No significant differences between glucose content in sham animals and the cortical and subcortical area could be measured over time; the subcortical glucose content was bilaterally lower than cortical content at all time points and reached a significant minimum bilaterally at 48 h after repetitive CCI injury compared with cortical glucose content. Single CCI injury did not affect ATP, glucose, and lactate contents at any time point. Repetitive CCI injury caused a more severe depression in cerebral metabolism at early time points after trauma compared with a single CCI injury and indicates that lactate might be an early indicator of post-traumatic metabolic disruption.

Biphasic elevation in cerebrospinal fluid and plasma concentrations of endothelin 1 after traumatic brain injury in human patients.

Severe traumatic brain injury (TBI) is characterized by a high mortality and poor outcome. The pathomechanisms involved are cytokine-mediated proinflammatory and anti-inflammatory reactions and significant cerebral microcirculatory disorders. The role of endothelin 1 (ET-1), a very potent vasoconstrictive peptide, in the deterioration of cerebral perfusion after trauma is still unclear. The presented study investigated the changes in ET-1 in the cerebrospinal fluid (CSF) and plasma after TBI in humans, with special regard to the presence of subarachnoid hemorrhage (SAH) and clinical outcome. Twenty patients with TBI were consecutively enrolled into the study, 10 patients without SAH (TBI group) and 10 patients with SAH (TBI-H group). Paired samples of plasma and CSF were collected for 10 days after trauma. Analysis of the ET-1 concentrations showed that TBI is associated with initially increased ET-1 values in plasma (TBI, day 1; TBI-H, days 2-3) and significantly increased (P < 0.05, vs. control) CSF concentrations (TBI, days 1-2; TBI-H, days 1-3) in the first days after trauma. In the further time course, ET-1 values declined in both groups, reaching reference values in plasma. The CSF values remained significantly (P < 0.05 vs. control) elevated. Both groups showed a second peak on the beginning of the second week after trauma in plasma and CSF. Whereas plasma concentrations failed to reach significance, CSF values showed a significant peak on day 7 in both groups. The TBI-H patients had significantly (P < 0.05) higher values in the secondary peak compared with patients of the TBI group. The kinetics of traumatic SAH-dependent ET-1 needs to be assessed in further investigations.

Delayed elevation of soluble tumor necrosis factor receptors p75 and p55 in cerebrospinal fluid and plasma after traumatic brain injury.

Recent studies have reported a significant inflammatory reaction in the brain and the systemic circulation after traumatic brain injury (TBI). Although there is growing knowledge and understanding of the mechanisms and mediators involved in the proinflammatory reaction, little is known about the anti-inflammatory mediators in the brain. As tumor necrosis factor alpha (TNF-alpha) plays a detrimental role in the initiation and promotion of the proinflammatory reactions after TBI, the endogenous scavenger system, represented by the soluble TNF receptors (sTNFRs) p55 and p75, seems to have an important anti-inflammatory capacity by binding to circulating TNF-alpha. To evaluate this potentially anti-inflammatory response to trauma, we analyzed sTNFR p55 and p75 in paired plasma/cerebrospinal fluid (CSF) samples of 29 patients who encountered TBI. Values were compared with reference values obtained from healthy volunteers (n = 91). Patients with TBI showed significantly (P < 0.001) elevated sTNFR p55 and p75 values starting from day 2 and lasting until day 10 if compared with reference values. In contrast to the early increased plasma values p55 and p75 showed slowly increasing CSF values starting on day 4 and 3, respectively. Significantly (P < 0.001) increased CSF values of p 55 were determined on days 4 to 6 and day 9. p75 showed significantly (P < 0.001) elevated values if compared with control values on days 7 and 9. The sTNFR p55 and p75 show a distinct and long-lasting elevation in plasma of patients after TBI. In contrast, CSF values display a delayed and less intense elevation of both receptors in patients with TBI. These findings are suggestive of an imbalance of the proinflammatory and anti-inflammatory reactions of the central nervous system after trauma, with an emphasis on the proinflammatory mechanisms and a slow increase of potentially anti-inflammatory mediators such as the soluble TNFRs after TBI.

Fracture and retrosternal dislocation of the medial clavicle in a 12-year-old child--case report, options for diagnosis, and treatment in children.

We report a retrosternally displaced epiphysiolysis in a 12-year-old child and discuss options for the most appropriate diagnostic and therapeutic approach. If a standard anteroposterior view of the shoulder girdle shows abnormalities or if appropriate clinical suspicion is present, we strongly favor an magnetic resonance imaging study for further workup instead of a computed tomographic scan, which is currently the diagnostic method of choice in clinical algorithms. Radiation exposure is thereby limited and maximum information about possible mediastinal soft tissue complications is obtained using a single diagnostic tool. If open reduction is indicated, retention of the joint or approximation of physeal fracture or treatment of ligamentous injury should be performed without metal devices. These suggestions for future management of these patients should further reduce the use of x-rays in children. In addition, applying a suture instead of using metal for stabilization can avoid the extensively described complications in literature that can potentially result from metal devices. In addition, sutures circumvent the need for a second operation for metal removal.

Temporal window of vulnerability to repetitive experimental concussive brain injury.

OBJECTIVE: Repetitive concussive brain injury (CBI) is associated with cognitive alterations and increased risk of neurodegenerative disease. METHODS: To evaluate the temporal window during which the concussed brain remains vulnerable to a second concussion, anesthetized mice were subjected to either sham injury or single or repetitive CBI (either 3, 5, or 7 days apart) using a clinically relevant model of CBI. Cognitive, vestibular, and sensorimotor function (balance and coordination) were evaluated, and postmortem histological analyses were performed to detect neuronal degeneration, cytoskeletal proteolysis, and axonal injury. RESULTS: No cognitive deficits were observed in sham-injured animals or those concussed once. Mice subjected to a second concussion within 3 or 5 days exhibited significantly impaired cognitive function compared with either sham-injured animals (P < 0.05) or mice receiving a single concussion (P < 0.01). No cognitive deficits were observed when the interconcussion interval was extended to 7 days, suggestive of a transient vulnerability of the brain during the first 5 days after an initial concussion. Although all concussed mice showed transient motor deficits, vestibulomotor dysfunction was more pronounced in the group that sustained two concussions 3 days apart (P < 0.01 compared with all other groups). Although scattered degenerating neurons, evidence of cytoskeletal damage, and axonal injury were detected in selective brain regions between 72 hours and 1 week after injury in all animals sustaining a single concussion, the occurrence of a second concussion 3 days later resulted in significantly greater traumatic axonal injury (P < 0.05) than that resulting from a single CBI. CONCLUSION: These data suggest that a single concussion is associated with behavioral dysfunction and subcellular alterations that may contribute to a transiently vulnerable state during which a second concussion within 3 to 5 days can lead to exacerbated and more prolonged axonal damage and greater behavioral dysfunction.

Transient loss of microtubule-associated protein 2 immunoreactivity after moderate brain injury in mice.

Microtubule-associated protein 2 (MAP2) is important for microtubule stability and neural plasticity and appears to be among the most vulnerable of the cytoskeletal proteins under conditions of neuronal injury. To evaluate the acute effects of moderate severity traumatic brain injury on MAP2, anesthetized, adult male C57BL/6 mice were subjected to controlled cortical impact brain injury. At 5 min, 15 min, 90 min, 4 h, and 24 h following brain injury (n = 4 injured and n = 1 sham-injured per time point), mice were sacrificed and immunohistochemistry was performed on coronal brain sections. Profound decreases in MAP2 immunolabeling were observed in the ipsilateral cortex and hippocampal dentate hilus at 5 min postinjury and in the ipsilateral hippocampal CA3 area by 4 h postinjury. Decreases in MAP2 labeling occurred prior to notable neuronal cell loss. Interestingly, cortical MAP2 immunoreactivity returned by 90 min postinjury, but the recovery was short-lived within the core in comparison to the periphery of the impact site. Partial restoration of MAP2 immunoreactivity was also observed in the ipsilateral CA3 and dentate hilus by 24 h postinjury. Our data corroborate that MAP2 is an early and sensitive marker for neuronal damage following traumatic brain injury. Acute MAP2 loss, however, may not necessarily presage neuronal death, even following moderate severity traumatic brain injury. Rather, to the best of our knowledge, our data are the first to suggest an intrinsic ability of the traumatized brain for MAP2 recovery after injury of moderate severity.

Effects of underwater sound exposure on neurological function and brain histology.

To evaluate the safety of sonar exposure from a neurological perspective, the vulnerability of the central nervous system to underwater exposure with high-intensity, low-frequency sound (HI-LFS) was experimentally examined. Physiological, behavioral and histological parameters were measured in anesthetized, ventilated rats exposed to brief (5 min), underwater HI-LFS. Exposure to 180 dB sound pressure level (SPL) re 1 microPa at 150 Hz (n = 9) did not alter acute cardiovascular physiology (arterial blood pH, pO(2), pCO(2), heart rate, or mean arterial blood pressure) from that found in controls (n = 11). Rats exposed to either 180 dB SPL re 1 microPa at 150 Hz (n = 12) or 194 dB SPL re 1 microPa at 250 Hz (n = 12) exhibited normal cognitive function at 8 and 9 days after sound exposure. Evaluation of neurological motor function revealed a minor deficit 7 days after 180 dB SPL/150 Hz exposure that resolved by 14 days, and no deficits after 194 dB SPL/250 Hz exposure. No overt histological damage was detected in any group. These data suggest that underwater HI-LFS exposure may cause transient, mild motor dysfunction.

Transplanted neural stem cells survive, differentiate, and improve neurological motor function after experimental traumatic brain injury.

OBJECTIVE: Using the neural stem cell (NSC) clone C17.2, we evaluated the ability of transplanted murine NSCs to attenuate cognitive and neurological motor deficits after traumatic brain injury. METHODS: Nonimmunosuppressed C57BL/6 mice (n = 65) were anesthetized and subjected to lateral controlled cortical impact brain injury (n = 52) or surgery without injury (sham operation group, n = 13). At 3 days postinjury, all brain-injured animals were reanesthetized and randomized to receive stereotactic injection of NSCs or control cells (human embryonic kidney cells) into the cortex-hippocampus interface in either the ipsilateral or the contralateral hemisphere. One group of animals (n = 7) was killed at either 1 or 3 weeks postinjury to assess NSC survival in the acute posttraumatic period. Motor function was evaluated at weekly intervals for 12 weeks in the remaining animals, and cognitive (i.e., learning) deficits were assessed at 3 and 12 weeks after transplantation. RESULTS: Brain-injured animals that received either ipsilateral or contralateral NSC transplants showed significantly improved motor function in selected tests as compared with human embryonic kidney cell-transplanted animals during the 12-week observation period. Cognitive dysfunction was unaffected by transplantation at either 3 or 12 weeks postinjury. Histological analyses showed that NSCs survive for as long as 13 weeks after transplantation and were detected in the hippocampus and/or cortical areas adjacent to the injury cavity. At 13 weeks, the NSCs transplanted ipsilateral to the impact site expressed neuronal (NeuN) or astrocytic (glial fibrillary acidic protein) markers but not markers of oligodendrocytes (2'3'cyclic nucleotide 3'-phosphodiesterase), whereas the contralaterally transplanted NSCs expressed neuronal but not glial markers (double-labeled immunofluorescence and confocal microscopy). CONCLUSION: These data suggest that transplanted NSCs can survive in the traumatically injured brain, differentiate into neurons and/or glia, and attenuate motor dysfunction after traumatic brain injury.

Changes in regional energy metabolism after cortical cold lesion in the rat brain.

In the present investigation, regional ATP, glucose, and lactate contents were examined in the cortical and subcortical structures after cold lesion in rats. Bioluminescence imaging of ATP, glucose, and lactate was performed in serial tissue sections at 4 h (n = 4), 12 h (n = 4) and 24 h (n = 4) after cold injury or sham surgery. Bioluminescence images were analyzed by computer-assisted densitometry, at the lesion site, in cortical areas, in the hippocampus, and in the thalamus. ATP and glucose content were significantly decreased at the lesion site as well as on the contralateral side after 4, 12, and 24 h postinjury Lactate content increased significantly in the hippocampal area on the ipsilateral side at 12 h. Cortical lactate was bilaterally unchanged. The cold lesion injury led to a characteristic ischemic profile in the hippocampus signaled by low ATP and glucose content paralleled by high lactate levels. The otherwise global depletion of glucose and ATP suggests that other factors besides cerebral blood flow may contribute to the impairment of energy metabolism.

Rapid loss and partial recovery of neurofilament immunostaining following focal brain injury in mice.

Neurofilaments (NF), the intermediate filaments of the neuronal cytoskeleton, provide mechanical stability to the cell. High-molecular-weight NF (NFH) comprises a heavily phosphorylated carboxyl terminal ("sidearm") domain which helps determine interfilament spacing distances. Experimental evidence suggests that dephosphorylation greatly increases the rate and extent of proteolysis of NFH. Because NF proteolysis has been implicated as one pathogenic mechanism underlying cell death following traumatic brain injury (TBI), we analyzed the patterns of acute NFH damage in relation to phosphorylation state following focal, concussive, controlled cortical impact (CCI) brain injury in mice. Brains from C57BL/6 male mice (n = 4 injured and n = 1 sham per time point) were evaluated 5 min, 15 min, 90 min, 4 h, and 24 h following CCI injury (1 mm depth, 5 m/s). Immunohistochemistry was performed using antibodies that recognize epitopes on either dephosphorylated (d-NFH) or phosphorylated (p-NFH) sidearms or on the core (c-NFH) domain. As early as 5-15 min postinjury, immunoreactivity for d-, p-, and c-NFH decreased in the ipsilateral cortex, and hippocampal CA3, CA1, and dentate areas. This marked decrease of NFH labeling occurred in the absence of notable cell loss. Furthermore, partial recovery of NFH labeling was observed as early as 90 min postinjury in the cortex and by 24 h postinjury in hippocampal CA3 and dentate. The results of this study suggest that both phosphorylated and dephosphorylated NFH are vulnerable almost immediately following focal brain injury in mice, but that injured neurons may have an adaptive capability to partially restore this important cytoskeletal protein.