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Bradykinin (BK) was shown to stimulate the production of physiologically active metabolites, blood-brain barrier disruption, and brain edema. The aim of this prospective study was to measure BK concentrations in blood and cerebrospinal fluid (CSF) of patients with traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH), and ischemic stroke and to correlate BK levels with the extent of cerebral edema and intracranial pressure (ICP). Blood and CSF samples of 29 patients suffering from acute cerebral lesions (TBI, 7; SAH,: 10; ICH, 8; ischemic stroke, 4) were collected for up to 8 days after insult. Seven patients with lumbar drainage were used as controls. Edema (5-point scale), ICP, and the GCS (Glasgow Coma Score) at the time of sample withdrawal were correlated with BK concentrations. Though all plasma-BK samples were not significantly elevated, CSF-BK levels of all patients were significantly elevated in overall (n=73) and early (≤72 h) measurements (n=55; 4.3±6.9 and 5.6±8.9 fmol/mL), compared to 1.2±0.7 fmol/mL of controls (p=0.05 and 0.006). Within 72 h after ictus, patients suffering from TBI (p=0.01), ICH (p=0.001), and ischemic stroke (p=0.02) showed significant increases. CSF-BK concentrations correlated with extent of edema formation (r=0.53; p<0.001) and with ICP (r=0.49; p<0.001). Our results demonstrate that acute cerebral lesions are associated with increased CSF-BK levels. Especially after TBI, subarachnoid and intracerebral hemorrhage CSF-BK levels correlate with extent of edema evolution and ICP. BK-blocking agents may turn out to be effective remedies in brain injuries.

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INTRODUCTION: Objective of this investigation was to evaluate the rotational mobility at the craniocervical junction and changes in the width of the subarachnoid space during head rotation in healthy volunteers using Magnetic Resonance Imaging (MRI). MATERIALS AND METHODS: In 30 healthy volunteers axial 3mm Half-Fourier Acquisition Single-Shot Turbo Spin-Echo (HASTE) sequences were obtained with the subject's head in neutral position, and in maximal rotation to the left and right respectively. All MRI examinations were evaluated by two neuroradiologists in consensus. The ranges of axial rotation at C0-C2 as well as the width of the subarachnoid space in neutral, and in maximal rotated position were measured. Student's t-tests were used to compare group differences. RESULTS: Total range of right-to-left-rotation at C0-C2 was 59-183° with mean rotation to the right and left side of 70° (±12.7°) and 75° (±13.0°). Difference between degrees of rotation to both sides was on average 4.9° (±7.1°) with a significantly greater rotational range to the left compared to the right. In neutral position, distance between the dura and the ventral wall of the cervical spinal cord was 1.6-4.2mm. In active rotation interface between dura and myelon was evident in 19 volunteers with unilateral contact in 7, and bilateral contact in 12 cases. CONCLUSIONS: High variablity of rotational mobility at the craniocervical junction and attenuation of width of the subarachnoid space during head rotation are frequent findings in an asymptomatic population. Our results indicate that the assessment of these parameters is of limited diagnostic value in patients with whiplash-associated disorders.

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STUDY DESIGN: A prospective study of healthy volunteers. OBJECTIVE: To evaluate the influence of magnetic resonance imaging (MRI) field strength on the delineation and signal intensity of alar ligaments (AL) in healthy volunteers. SUMMARY OF BACKGROUND DATA: The fact that AL physiologically show morphologic variabilities is well established. However, presence and etiology of high-signal intensities within the AL as well as the influence of the MRI field strength on the signal characteristics of AL are still not completely understood. METHODS.: Coronal and sagittal 2-mm proton-density weighted sequences were acquired in 50 healthy volunteers using different MRI field strengths (1 T, 1.5 T, 3 T). Delineation and signal characteristics of AL were evaluated by 2 neuroradiologists independently. Differences concerning delineation and signal intensity between the MRI scanners, inter rater reliability between the 2 readers, and intrarater reliability at different time points were calculated. RESULTS: Delineation of AL was significantly better both on 3 T and 1.5 T than on 1 T (P = 0.05) in sagittal as well as in coronal view. In coronal view delineation was significantly better on 3 T than on 1.5 T, whereas in sagittal view no significant difference was evident when comparing 1.5 T and 3 T. Concerning signal intensity of AL in sagittal view, there was no significant difference between the 3 different field strengths. Inter-rater and intrarater agreements were fair to moderate with respect to delineation as well as signal intensity of AL. CONCLUSION: 1.5 T and 3 T significantly improve the delineation of AL when compared with lower field strength (1 T), but signal intensity of the AL in healthy volunteers is not influenced by the field strength. Increased signal is present in asymptomatic subjects on both low- and high-field magnetic resonance systems. Accordingly, the pathologic relevance of increased signal intensity of the AL, regardless of field strength, may not be indicative of traumatic AL injury.

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BACKGROUND AND OBJECTIVE: The diagnostic yield from fluoroscopy-guided bronchoscopic transbronchial biopsy of small solitary pulmonary nodules is low. The hypothesis tested in the present study was that the diagnostic yield can be significantly increased by combining flexible bronchoscopy with CT-guidance using a dedicated low-dose protocol. METHODS: CT-guided transbronchial biopsies were performed in 15 patients with a newly diagnosed solitary peripheral pulmonary nodule and negative conventional bronchoscopic biopsies under fluoroscopic guidance. For imaging, a multi-detector helical CT unit, adjusted at 120 kV, 15 mAs/slice, 4 x 5 mm collimation, 10 mm reconstructed slice thickness and a maximal scan length of 150 mm, was used. After advancing the biopsy forceps towards the lesion, a CT scan was obtained. When the tip of the forceps reached or penetrated the lesion a biopsy was taken, otherwise the procedure was repeated with a maximum of eight attempts. The effective radiation dose was calculated. RESULTS: The average diameter of the nodules was 23 +/- 6 mm (mean +/- SD) with a maximum distance to the parietal pleura of 18 mm (mean 6.5 mm). A mean of 4.1 (range 2-8) CT scans was performed to localize the lesion. In four patients, the forceps only reached the periphery of the nodule. In one patient, the nodule was missed in all attempts. Histology was malignant in eight patients and benign in four patients. In three patients, biopsy results were false negative (benign or non-specific instead of malignant). The overall diagnostic yield was 73%. Complications consisted of two pneumothoraces, one of which necessitated a chest tube. Mean effective radiation dose was 0.55 mSv (range 0.3-1.0). CONCLUSIONS: CT-guided transbronchial biopsy can be a valuable diagnostic tool in evaluating solitary pulmonary nodules. This applies for selected patients when other diagnostic methods are either unavailable or inappropriate. The diagnostic yield is high and, when a low-dose protocol is used, radiation exposure can be kept at a minimum.

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STUDY DESIGN: Case report. OBJECTIVE: To describe and discuss the case of a patient, later recognized to have sickle cell trait (SCT), who suffered from tuberculous spondylodiscitis and developed a spinal ischemia after spinal decompression and stabilization and to discuss the literature on this. SUMMARY OF BACKGROUND DATA: Spinal ischemia is a rare event and even more unusual after spinal surgery. Vaso-occlusive complications like strokes occur in patients with sickle cell disease, but spinal ischemia has rarely been reported. SCT is generally seen as a benign disorder with vaso-occlusive complications having been described under extreme conditions. METHODS: We report the case of a 39-year-old woman, born in Togo and living in Germany for more than 11 years, who presented to our outpatient clinics with a tuberculous spondylodiscitis. She underwent a dorsal decompression and pedicle screw instrumentation from T7-T11. RESULTS: A few hours after surgery, the patient developed an acute paraplegia of the lower extremities, which accentuated on the left side combined with urinary incontinence and anal sphincter dysfunction but without sensory deficits of the lower extremities. A CT-scan and a second-look surgery revealed no cause for the symptoms. A magnetic resonance imaging showed that the patient had suffered spinal ischemia worst at the T4 level. On further investigation she was noted to have SCT. CONCLUSION: We assume that the combination of the patient's SCT status and the physiologic stress of surgery likely explain this patient's spinal ischemia.

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OBJECTIVE: To study the acquisition of bone mass and changes in bone mineral density (BMD) related to age, bone age, pubertal status, and growth hormone (GH) therapy in 11 children with juvenile idiopathic arthritis (JIA) longitudinally over 4 years, in comparison to healthy children. METHODS: Bone mineral content (BMC), BMD, and vertebral area were measured by dual energy x-ray absorptiometry. Since BMC and BMD increase with size, BMD was converted to volumetric BMD (vBMD) after adjustment for vertebral size. RESULTS: At inclusion all patients (7 female, 4 male, mean age 10.3 +/- 2.1 yrs) had low BMD, with a mean z-score for area BMD (aBMD) of -2.04 +/- 0.8 SD. After adjustment for size, vBMD was 0.198 g/cm3, and after 4 years of GH treatment it increased significantly to 0.232 g/cm3 (p < 0.03), expressed as SD scores that increased from -2.97 +/- 0.81 SD to -2.83 +/- 0.67 SD. In relation to bone age, vBMD SD increased from -2.53 +/- 0.85 to -2.41 +/- 0.79. Compared to pretreatment values, bone formation and resorption markers increased significantly during treatment. CONCLUSION: Our results reflect an increase in bone turnover under GH therapy in these patients. Despite biochemical changes there was a stabilization of vBMD for age and bone age, with a percentage increase comparable to healthy children. Longterm GH treatment will be necessary to evaluate a potential positive effect of GH on bone density and metabolism in patients with JIA.

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