Atlanto-occipital dislocation with concomitant severe traumatic brain injury: A retrospective study at a level 1 trauma center.

BACKGROUND: Traumatic atlanto-occipital dislocation (AOD) is a life-threatening injury. Although traumatic brain injury (TBI) is associated with increased mortality in AOD patients, a detailed individual analysis of these patients is lacking in the literature. METHODS: Patients ≥16 years old who were diagnosed of AOD with concomitant severe TBI from 2010 to 2020 were included in this retrospective study. We examined the epidemiology, injury mechanisms, associated injuries, and outcomes of these patients. RESULTS: Eight patients were included. Six patients died before any intervention could be performed, and two patients underwent an occipito-cervical fixation, showing a notorious neurologic improvement on follow-up. Cardiorespiratory arrest (CRA) was a strong predictor of subsequent death. CT signs of diffuse axonal injury (DAI) were present in most patients and were confirmed by magnetic resonance imaging (MRI) in survivors. Although TBI was not the main cause of death, it was responsible for the delayed neurological improvement and deferred stabilization. The average sensitivity of the different used methodologies for AOD diagnosis ranged from 0.50 to 1.00, being the Basion Dens Interval (BDI) and the Condyle-C1 interval (CCI) sum the most reliable criteria. Non-survivors tended to show greater distraction measurements. The high incidence of condylar avulsion fractures suggests that their visualization on the initial CT study should heighten the suspicion for AOD. CONCLUSIONS: Our data suggest that patients with AOD and concomitant severe TBI might be salvageable patients. In those who survive beyond the first hospital days and show neurological improvement, surgical treatment should be performed as they can achieve an important neurologic recovery.

Efficacy of percutaneous pedicle screws for thoracic and lumbar spine fractures compared with open technique.

BACKGROUND: The objective of this study is to compare percutaneous techniques (MIS) with the open technique in terms of angle correction, long-term maintenance and clinical results. METHODS: The authors collected a prospective database of thoraco-lumbar fractures treated with posterior stabilization without fusion from 2013 to 2019. The statistical analysis has been carried out retrospectively. The patients were classified into Open and MIS group. To compare the two population, samples, treatments and mitigate the differences between the groups, the propensity score (PS) matching was used. RESULTS: One hundred and eight patients with thoraco-lumbar fractures were included. After performing the PS, 21 patients were obtained in the open group and 28 in the MIS group. For operative and perioperative parameters there were no differences in number of patients with posterior decompression, number of instrumented segments, number of total screws, operative time and complications. Postoperative hemoglobin was similar in both groups. However, in the open group a greater loss of hemoglobin was observed; as well as, higher analgesia requirements and length of stay. No statistically significant differences were observed in neurological status in both groups in the preoperative, postoperative period and at follow-up. The Cobb angle showed no differences at admission comparing both groups. A similar angle correction was observed with both surgeries, but in open surgery there was a statistically significant loss of correction. CONCLUSIONS: We observed in this study that the MIS technique for the treatment of thoracolumbar fractures is as effective as the open technique in terms of angle correction; and demonstrated that is better in its maintenance over time. Clinical results were at least as good as with the open technique.

Effects of cranioplasty in cerebral blood perfusion using quantification with 99m-Tc HMPAO SPECT-CT.

BACKGROUND AND PURPOSE: Syndrome of the trephined or sinking skin flap syndrome is an underdiagnosed condition of craniectomized patients that usually improves after cranioplasty. Among the pathophysiological theories proposed, the changes of cerebral blood perfusion (CBP) caused by cranial defects might have a role in the neurological deficiencies observed. We aim to assess the regional cortex changes in CBP after cranioplasty with Technetium 99m hexamethylpropylene-amine oxime (99mTc-HMPAO) SPECT-CT. METHODS: Twenty-eight craniectomized patients subject to cranioplasty were studied with 99mTc-HMPAO SPECT-CT in three different times, before cranioplasty, a week, and 3 months after. The images were processed with quantification software comparing CBP of 24 cortical areas with a reference area, and with a database of controls. A mixed effects model and T-Student were used. RESULTS: CBP increased significantly in both hemispheres after cranioplasty, either using ratio (ß = .019, p-value = .030 first postsurgical SPECT-CT and ß = .021, p-value = .015 in the second study, vs. presurgical) or Z-score (ß = .220, p-value = .026 and ß = .279, p-value = .005, respectively). Nine areas of the damaged side had a significant lower CBP ratio and Z-score than the undamaged. Posterior cingulate showed an increased CBP ratio (p-value = .034) and Z-score (p-value = .028) in the first postsurgical SPECT-CT. These posterior cingulate changes represent a 4.83% increase in ratio and 91.04% in Z-Score (p-value = .035 and .040, respectively). CONCLUSION: CBP changes significantly in specific cortical areas after cranioplasty. Posterior cingulate changes might explain some improvements in attention impairments. SPECT-CT could be a useful tool to assess CBP changes in these patients and might be helpful in their clinical management.

Surgery for acute subdural hematoma: the value of pre-emptive decompressive craniectomy by propensity score analysis.

BACKGROUND: Acute subdural hematomas (ASDH) are found frequently following traumatic brain injury (TBI) and they are considered the most lethal type of mass lesions. The decision to perform a procedure to evacuate ASDH and the approach, either via craniotomy or decompressive craniectomy (DC), remains controversial. METHODS: We reviewed a prospectively collected series of 343 moderate to severe TBI patients in whom ASDH was the main lesion (ASDH volumes ≥10 cc). Patients with early comfort measures (early mortality prediction >50% and not ICP monitored), bilateral ASDH or the presence of another intracranial hematoma with volumes exceeding two times the volume of the ASDH were excluded. Among them, 112 were managed conservatively, 65 underwent ASDH evacuation by craniotomy and 166 by DC (103 pre-emptive DC, 63 obligatory DC). We calculated the average treatment effect by propensity score (PS) analysis using the following covariates: age, year, hypoxia, shock, pupils, major extracranial injury, motor score, midline shift, ASDH volume, swelling, intraventricular and subarachnoid hemorrhage presence. Then, multivariable binary regression and ordinal logistic regression analysis were performed to estimate associations between predictors and mortality and 12 months-GOS respectively. The patients' inverse probability weights were included as an independent variable in both regression models. RESULTS: The main variables associated with outcome were year, age, falls from patient´s own height, hypoxia, early deterioration, pupillary abnormalities, basal cistern effacement, compliance to ICP monitoring guidelines and type of surgical approach (craniotomy and pre-emptive DC). CONCLUSIONS: According to sliding dichotomy analysis, we found that patients in the intermediate or worst bands of unfavorable outcome prognosis seemed to achieve better than expected outcome if they underwent pre-emptive DC rather than craniotomy.

Serum assessment of traumatic axonal injury: the correlation of GFAP, t-Tau, UCH-L1, and NfL levels with diffusion tensor imaging metrics and its prognosis utility.

OBJECTIVE: Diagnosis of traumatic axonal injury (TAI) is challenging because of its underestimation by conventional MRI and the technical requirements associated with the processing of diffusion tensor imaging (DTI). Serum biomarkers seem to be able to identify patients with abnormal CT scanning findings, but their potential role to assess TAI has seldomly been explored. METHODS: Patients with all severities of traumatic brain injury (TBI) were prospectively included in this study between 2016 and 2021. They underwent blood extraction within 24 hours after injury and imaging assessment, including DTI. Serum concentrations of glial fibrillary acidic protein, total microtubule-associated protein (t-Tau), ubiquitin C-terminal hydrolase L1 (UCH-L1), and neurofilament light chain (NfL) were measured using an ultrasensitive Simoa multiplex assay panel, a digital form of enzyme-linked immunosorbent assay. The Glasgow Outcome Scale-Extended score was determined at 6 months after TBI. The relationships between biomarker concentrations, volumetric analysis of corpus callosum (CC) lesions, and fractional anisotropy (FA) were analyzed by nonparametric tests. The prognostic utility of the biomarker was determined by calculating the C-statistic and an ordinal regression analysis. RESULTS: A total of 87 patients were included. Concentrations of all biomarkers were significantly higher for patients compared with controls. Although the concentration of the biomarkers was affected by the presence of mass lesions, FA of the CC was an independent factor influencing levels of UCH-L1 and NfL, which positioned these two biomarkers as better surrogates of TAI. Biomarkers also performed well in determining patients who would have had unfavorable outcome. NfL and the FA of the CC are independent complementary factors related to outcome. CONCLUSIONS: UCH-L1 and NfL seem to be the biomarkers more specific to detect TAI. The concentration of NfL combined with the FA of the CC might help predict long-term outcome.

Reduction of Instrumentation-Related Spine Surgical Site Infections After Optimization of Surgical Techniques. A Single Center Retrospective Analysis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Although surgical risk factors for developing spine surgical site infections (S-SSI) have been identified, the impact of such knowledge in its prevention has not been demonstrated. METHODS: We evaluated in 500 patients undergoing spine surgery between 2011 and 2019 at Hospital 12 de Octubre the changes in S-SSI rates over time. Surgical variables independently related to S-SSI were analyzed by univariate and multivariate analysis using binary logistic regression models. A case-control sub-analysis (1:4), matched by the surgical variables identified in the overall cohort was also performed. RESULTS: Twenty cases of S-SSI were identified (4%), with a significant decrease in the incidence rate across consecutive time periods (6.6% [2011-2014] vs .86% [2015-2019]; P-value <.0001)). Multivariate analysis identified arthrodesis involving sacral levels (odds ratio [OR]: 2.57; 95% confidence interval [95%CI]: 1.02-6.47; P-value = .044) and instrumentation over 4-8 vertebrae (OR: 2.82; 95%CI: 1.1-7.1; P-value = .027) as independent risk factors for S-SSI. The reduction in the incidence of S-SSI concurred temporally with a reduction in instrumentations involving 4-8 vertebrae (55% vs 21.8%; P-value <.0001) and sacral vertebrae (46.9% vs 24.6%; P-value <.0001) across both periods. The case-control analysis matched by these surgical variables failed to identify other factors independently related to the occurrence of S-SSI. CONCLUSIONS: Spinal fusion of more than 4 levels and the inclusion of sacral levels were independently related to the risk of S-SSI. Optimization of surgical techniques by reducing these two types of instrumentation could significantly reduce S-SSI rates.

Hemodynamic alterations following a cerebellar arteriovenous malformation resection: Case report and densitometric quantitative analysis from CT imaging.

BACKGROUND: Cerebellar arteriovenous malformations (cAVMs) are rare and challenging lesions with an aggressive natural history. The mechanisms whereby a patient can worsen clinically after a supratentorial AVM resection include an acute alteration in cerebral hemodynamics, which is a known cause of postoperative hyperemia, edema and/or hemorrhage. These phenomena has not been described for cAVMS. Moreover, the underlying pathophysiology of edema and hemorrhage after AVM resection still remains controversial. METHODS: We report a patient that presented an abrupt neurological deterioration after cAVM surgical resection. Emergent external ventricular drainage to treat incipient hydrocephalus only partially reverted the patient's deterioration. Consecutive post-surgery CT images revealed fourth ventricle compression secondary to cerebellar swelling that concurred with a new neurological deterioration. Densitometric analysis was performed in these CT images to reveal the nature of these changes as well as their evolution over time. RESULTS: Importantly, we demonstrated a dynamic increase in the cerebellum mean density at the interval of Hounsfield values which correspond to hyperemia values. These changes were dynamic, and when hyperemia resolved and cerebellar density returned to basal levels, the fourth ventricle re-expanded and the patient neurologically recovered. CONCLUSIONS: This study demonstrated the utility of quantitative CT image analysis in the context of hemodynamic alterations following cAVM resection. Densitometric CT analysis demonstrated that hyperemic changes, but not ischemic ones, were time-dependent and were responsible for swelling and hemorrhage that conditioned neurological status and patient's evolution.

Clinical improvement after cranioplasty and its relation to body position and cerebral hemodynamics.

Cranioplasty after decompressive craniectomy (DC) has been found to improve the neurological condition. The underlying mechanisms are still unknown. The aim of this study is to investigate the roles of the postural changes and atmospheric pressure (AP) in the brain hemodynamics and their relationship with clinical improvement. Seventy-eight patients were studied before and 72 h after cranioplasty with cervical and transcranial color Doppler ultrasound (TCCS) in the sitting and supine positions. Craniectomy size, shape, and force exerted by the AP (torque) were calculated. Neurological condition was assessed with the National Institutes of Health Stroke Scale (NIHSS) and the Barthel index. Twenty-eight patients improved after cranioplasty. Their time elapsed from the DC was shorter (214 vs 324 days), preoperative Barthel was worse (54 vs 77), internal carotid artery (ICA) mean velocity of the defect side was lower while sitting (14.4 vs 20.9 cm/s), and torque over the craniectomy was greater (2480.3 vs 1464.3 N*cm). Multivariate binary logistic regression showed the consistency of these changes. TCCS findings were no longer present postoperatively. Lower ICA (defect side) velocity in the sitting position correlates significantly with clinical improvement. Greater torque exerted by the AP might explain different susceptibilities to postural changes, corrected by cranioplasty.

The influence of aneurysm morphology on the volume of hemorrhage after rupture.

OBJECTIVE: Factors determining the risk of rupture of intracranial aneurysms have been extensively studied; however, little attention is paid to variables influencing the volume of bleeding after rupture. In this study the authors aimed to evaluate the impact of aneurysm morphological variables on the amount of hemorrhage. METHODS: This was a retrospective cohort analysis of a prospectively collected data set of 116 patients presenting at a single center with subarachnoid hemorrhage due to aneurysmal rupture. A volumetric assessment of the total hemorrhage volume was performed from the initial noncontrast CT. Aneurysms were segmented and reproduced from the initial CT angiography study, and morphology indexes were calculated with a computer-assisted approach. Clinical and demographic characteristics of the patients were included in the study. Factors influencing the volume of hemorrhage were explored with univariate correlations, multiple linear regression analysis, and graphical probabilistic modeling. RESULTS: The univariate analysis demonstrated that several of the morphological variables but only the patient's age from the clinical-demographic variables correlated (p < 0.05) with the volume of bleeding. Nine morphological variables correlated positively (absolute height, perpendicular height, maximum width, sac surface area, sac volume, size ratio, bottleneck factor, neck-to-vessel ratio, and width-to-vessel ratio) and two correlated negatively (parent vessel average diameter and the aneurysm angle). After multivariate analysis, only the aneurysm size ratio (p < 0.001) and the patient's age (p = 0.023) remained statistically significant. The graphical probabilistic model confirmed the size ratio and the patient's age as the variables most related to the total hemorrhage volume. CONCLUSIONS: A greater aneurysm size ratio and an older patient age are likely to entail a greater volume of bleeding after subarachnoid hemorrhage.

Implant Microbial Colonization Detected by Sonication as a Cause for Spinal Device Failure: A Prospective Study.

STUDY DESIGN: A prospective single center observational study. OBJECTIVES: The aim of this study was to examine the potential role of sonication in the diagnosis of low-grade infections and its association with pedicle screw (PS) loosening, and to describe risk factors and radiological findings associated with spinal implant infection. SUMMARY OF BACKGROUND DATA: Although PS loosening has mainly been attributed to mechanical overload, implant colonization and biofilm formation have recently been suggested. Culturing of sonication fluid implants is promising in the field of spine instrumentation infection, but little data are available. METHODS: We prospectively included all patients who were subjected to implant removal. PS loosening was assessed with computed tomography (CT) scan. Different clinical and radiological parameters which could serve as indicators of implant infection were studied. RESULTS: Thirty-eight patients were included in the study and 11 of them (29%) had a positive sonication result. Patients with spinal implant infection were associated with screw loosening (P = 0.005). Particularly, those screws with a positive microbiological culture showed signs of screw loosening in the preoperative CT scan (P < 0.001). Our results also showed that radiological screw loosening at L1-L3 level, and loosened larger constructs were associated with screw microbial colonization. The most common isolated microorganisms were coagulase-negative staphylococci and Cutibacterium acnes. An implant-based multivariate analysis indicated that screw loosening, the absence of prophylactic cefazolin, ICU hospitalization, screw breakage, and L1-L3 spine level were independent risk factors for implant-associated infection. Our model exhibited a high predictive power with an area under the curve of 0.937. CONCLUSION: As clinical presentation of deep implant chronic infection is unspecific, consideration of these factors enables preoperative prediction and risk stratification of implant colonization, thus helping patient's management.Level of Evidence: 3.

Hemodynamic alterations following a cerebellar arteriovenous malformation resection: Case report and densitometric quantitative analysis from CT imaging.

BACKGROUND: Cerebellar arteriovenous malformations (cAVMs) are rare and challenging lesions with an aggressive natural history. The mechanisms whereby a patient can worsen clinically after a supratentorial AVM resection include an acute alteration in cerebral hemodynamics, which is a known cause of postoperative hyperemia, edema and/or hemorrhage. These phenomena has not been described for cAVMS. Moreover, the underlying pathophysiology of edema and hemorrhage after AVM resection still remains controversial. METHODS: We report a patient that presented an abrupt neurological deterioration after cAVM surgical resection. Emergent external ventricular drainage to treat incipient hydrocephalus only partially reverted the patient's deterioration. Consecutive post-surgery CT images revealed fourth ventricle compression secondary to cerebellar swelling that concurred with a new neurological deterioration. Densitometric analysis was performed in these CT images to reveal the nature of these changes as well as their evolution over time. RESULTS: Importantly, we demonstrated a dynamic increase in the cerebellum mean density at the interval of Hounsfield values which correspond to hyperemia values. These changes were dynamic, and when hyperemia resolved and cerebellar density returned to basal levels, the fourth ventricle re-expanded and the patient neurologically recovered. CONCLUSIONS: This study demonstrated the utility of quantitative CT image analysis in the context of hemodynamic alterations following cAVM resection. Densitometric CT analysis demonstrated that hyperemic changes, but not ischemic ones, were time-dependent and were responsible for swelling and hemorrhage that conditioned neurological status and patient's evolution.

Positive outcome after endoscopic treatment of a symptomatic convexity arachnoid cyst in an elderly.

Cerebral convexity arachnoid cysts (ACs) only represent around 10-14% of the cysts. Symptomatic ACs in the elderly are rare. We present a 66-year-old woman with headache and a focal epileptic seizure. Imaging revealed a left parietal AC. Conservative management chosen but the patient's neurological condition worsened, and an endoscopic fenestration was then performed. Postoperatively, her symptoms completely resolved and MRI image showed significant shrinkage of the AC.

Accuracy of percutaneous pedicle screws for thoracic and lumbar spine fractures compared with open technique.

BACKGROUND: This study aimed to compare the accuracy of screw placement between open pedicle screw fixation and percutaneous pedicle screw fixation (MIS) for the treatment of thoracolumbar spine fractures (TSF). METHODS: forty-nine patients with acute TSF who were treated with transpedicular screw fixation from January 2013 to December 2016 were retrospectively reviewed. The patients were divided into Open and MIS groups. Laminectomy was performed in either group if needed. The accuracy of the screw placement, the evolution of the Cobb sagittal angle postoperatively and at 12-month follow-up and the neurological status were recorded. AO type of fracture and TLICS score were also recorded. RESULTS: Mean age was 42 years old. Mean TLICS score was 6.29 and 5.96 for open and MIS groups respectively. Twenty-five MIS and 24 open surgeries were performed, and 350 (175 in each group) screws were inserted (7.14 per patient). Twenty-four and 13 screws were considered "out" in the open and MIS groups respectively (Odds ratio 1.98. 0.97-4,03 P=0.056). The Cobb sagittal angle went from 13.3º to 4.5º and from 14.9º to 8.2º in the Open and MIS groups respectively (both P<0.0001). Loss of correction at 12-month follow-up was 3.2º and 4.2º for the open and MIS groups, respectively. No neurological worsening was observed. CONCLUSIONS: For the treatment of acute thoracolumbar fractures, the MIS technique seems to achieve similar results to the open technique in relation to neurological improvement and deformity correction, while placing the screws more accurately.

Snorting the Brain Away: Cerebral Damage as an Extension of Cocaine-Induced Midline Destructive Lesions.

Cocaine consumption is associated with a variety of clinical manifestations. Though cocaine intranasal inhalation always determines nasal mucosal damages, extensive septum perforations, and midline destructions-known as cocaine-induced midline destructive lesions (CIMDL)-affect only a limited fraction of patients. CIMDL is viewed as a cocaine-associated autoimmune phenomenon in which the presence of atypical anti-neutrophil cytoplasmic antibody (ANCA) promotes and/or defines the disease phenotype. A 51-year-old man presented with an intracranial tumor-like lesion by its space-occupying effect. CT also revealed the destruction of the nasal septum and skull base. A diagnosis of CIMDL was made in light of the patient's history as well as findings of the physical and endoscopic examinations, imaging studies, and laboratory testing. There was no evidence of other pathologies. Histopathological results from cerebral biopsy led us to consider the intracranial pathology as an extension of the CIMDL. CIMDL is the result of a necrotizing inflammatory tissue response triggered by cocaine abuse in a subset of predisposed patients. The reported case is the first CIMDL consistent with brain extension mimicking a tumor-like lesion. While the presence of atypical ANCA seems to promote and/or define the disease phenotype, the specific role of these and other circulating autoantibodies needs further investigation.

Reduction in the infection rate of cranioplasty with a tailored antibiotic prophylaxis: a nonrandomized study.

BACKGROUND: Cranioplasty carries a high risk of surgical site infections (SSIs) for a scheduled procedure, particularly with antibiotic-resistant bacteria. METHODS: The goal of this retrospective study was to measure the effect of tailored antibiotic prophylaxis on SSIs resulting from cranioplasties. The authors collected a prospective database of cranioplasties from 2009 to 2018. Risk factors for SSI were registered, as well as infection occurring during the first year postoperatively. A new protocol was initiated in 2016 consisting of antibiotic prophylaxis tailored to the colonizing flora of the skin of the scalp and decolonization of patients who were nasal carriers of methicillin-resistant S. aureus (MRSA); infection rates were compared. RESULTS: One hundred nine cranioplasties were identified, 64 in the old protocol and 45 in the new protocol. Of the 109 cranioplasties, 16 (14.7%) suffered an infection, 14 (21.9%) in the old protocol group and 2 (4.4%) in the new protocol group (OR for the new protocol 0.166, 95% CI 0.036-0.772). Multiple surgeries (OR 3.44), Barthel ≤ 70 (OR 3.53), and previous infection (OR 3.9) were risk factors for SSI. Of the bacteria identified in the skin of the scalp, 22.2% were resistant to routine prophylaxis (cefazoline). Only one patient was identified as a nasal carrier of MRSA and was decolonized. CONCLUSIONS: A high percentage of bacteria resistant to routine prophylaxis (cefazoline) was identified in the skin of these patients' scalps. The use of tailored antibiotic prophylaxis reduced significantly the infection rate in this particular set of patients.

Delayed extensive brain edema caused by the growth of a giant basilar apex aneurysm treated with basilar artery obliteration: a case report.

BACKGROUND: Partially thrombosed giant aneurysms at the basilar apex (BA) artery are challenging lesions with a poor prognosis if left untreated. Here we describe a rare case of extensive brain edema after growth of a surgically treated and thrombosed giant basilar apex aneurysm. CASE PRESENTATION: We performed a proximal surgical basilar artery occlusion on a 64-year-old female with a partially thrombosed giant BA aneurysm. MRI showed no ischemic lesions but showed marked edema adjacent to the aneurysm. She had a good recovery, but 3 months after surgical occlusion, her gait deteriorated together with urinary incontinence and worsening right hemiparesis. MRI showed that the aneurysm had grown and developed intramural hemorrhage, which caused extensive brain edema and obstructive hydrocephalus. She was treated by a ventriculoperitoneal shunt placement. Follow-up MRI showed progressive brain edema resolution, complete thrombosis of the lumen and shrinkage of the aneurysm. At 5 years follow-up the patient had an excellent functional outcome. CONCLUSIONS: Delayed growth of a surgically treated and thrombosed giant aneurysm from wall dissection demonstrates that discontinuity with the initial parent artery does not always prevent progressive enlargement. The development of transmural vascular connections between the intraluminal thrombus and adventitial neovascularization by the vasa vasorum on the apex of the BA seems to be a key event in delayed aneurysm growth. Extensive brain edema might translate an inflammatory edematous reaction to an abrupt enlargement of the aneurysm.

Occult thoracic disco-ligamentous Chance fracture in computed tomography: a case report.

We report on a 46-year-old woman who was involved in a road traffic accident. Neurological examination demonstrated paraplegia, while initial CT showed bilateral pneumothorax and hemothorax, rib fractures, a C2 vertebral body fracture with C2-C3 dislocation and active arterial bleeding at the sacral level. Given the fact that her neurological status did not particularly correspond with what we observed on CT scan, MRI was obtained due to the suspicion that a much more severe occult injury could be present. MRI showed a complete rupture of the posterior ligamentous complex along with the intervertebral disk and the posterior longitudinal ligament at T8-T9 level. The patient underwent minimally invasive posterior fixation with pedicle screws. Chance fractures of the thoracic spine are uncommon. To our knowledge, this is the first report of a pure soft-tissue Chance fracture located in the thoracic spine. Given that the initial CT showed no fracture evidence or vertebral malalignment, a high index of suspicion, based on the mechanism of injury, clinical examination and/or concomitant lesions, is necessary to identify such extremely unstable injury. Early recognition is crucial for appropriate therapy and to minimize the extent of neurological deficit.

Serum Amyloid A1 as a Potential Intracranial and Extracranial Clinical Severity Biomarker in Traumatic Brain Injury.

Extracranial injury is frequently present in patients with traumatic brain injury (TBI). However, no reliable biomarker exists nowadays to evaluate the magnitude and extension of extracranial injury as well as the identification of patients who are at risk of developing secondary injuries. The purpose of this study was to identify new possible peptide biomarkers by mass spectrometry analysis in patients with TBI and ascertain whether the novel biomarker discovered by peptide mass fingerprinting, serum amyloid A1 (SAA1), is capable of reflecting the condition of the patient and both intracranial and extracranial injury extension. Demographic characteristics, clinical data, and serum samples were prospectively collected from 120 patients with TBI (Glasgow Coma Scale [GCS] score 3-15) on admission. Biomarkers were quantified by enzyme-linked immunosorbent assay. Intracranial lesion volume was measured from the semiautomatic segmentation of hematoma on computed tomography (CT) using Analyze software. Functional outcome was evaluated using the Glasgow Outcome Scale (GOS) at hospital discharge and GOS extended scores at 6 months. The SAA1 levels were significantly associated with intracranial (GCS score at admission, lesion load measured with cranial CT, and pupil responsiveness) and extracranial clinical severity (all Abbreviated Injury Scale regions, Injury Severity Score, major extracranial injury, polytrauma, and orthopedic fractures presence), along with systemic secondary insults and functional outcome. SAA1 was is associated with the volume of traumatic intracranial lesions. The SAA1 levels were correlated with astroglial S100ß and glial fibrillary acidic protein (GFAP), neuronal neuron-specific enolase (NSE), and axonal total tau (T-tau) and phosphorylated neurofilament heavy chain (pNF-H) injury markers. SAA1 predicts unfavorable outcome and mortality at hospital discharge (area under the curve [AUC] = 0.90, 0.82) and 6 months (AUC = 0.89). SAA1 can be established as a marker for the overall patient condition due to its involvement in the neuroendocrine axis of the systemic response to craniocerebral trauma.