Preben Sørensen

Determining the sensitivity of computed tomography scanning in early detection of subarachnoid hemorrhage

Medical management is often the initial management of cervical spondylitic syndromes, including radiculopathy, myelopathy, and neck pain. This includes pharmacological and rehabilitation treatment. Prospective studies comparing the efficacy of surgical versus medical management are lacking. The indications and efficacy of pharmacological and rehabilitative treatments are reviewed. The use of anti-inflammatory drugs, muscle relaxants, analgesics, antidepressants, anticonvulsants, steroids, facet joint ablation, and physical therapy are reviewed. A rationale for the medical management of acute neck pain, chronic neck pain, radiculopathy, and myelopathy is presented.

Spinal epidural abscesses: conservative treatment for selected subgroups of patients

The aim of this study was to emphasize the importance of non-surgical treatment for subgroups of patients with spinal epidural abscesses (SEA). From 1988 to 2000, thirty cases of epidural spinal abscesses were retrospectively included in the study. The records and radiological studies were evaluated. Staphylococcus aureus was the most frequent microorganism causing SEA in 18 patients. In 20 patients SEA was secondary to interventional procedures. Predisposing factors were present in 15 cases. Fifty per cent was located in the lumbar region. A total of 22 patients received MRI, which always gave the diagnosis of SEA. Surgical treatment was performed in 20 patients. Conservative treatment with antibiotics was used in 10 patients. Eight patients did not have neurological deficits. One patient was critically ill and another patient was paralysed with an epidural lesion extending over six spinal segments. In all cases, a microorganism was known at the time of diagnosis of ESA. The eight patients without deficits recovered completely following treatment with antibiotics. C-reactive protein was the most reliable inflammatory marker to monitor the effect of the treatment. MRI enables diagnosis of ESA before deficits occur. These can safely be treated with antibiotics if the causative microorganism is known, and the neurological status and laboratory values are monitored. Decompressive surgery is restricted to cases with progressive deficits, when the deficits have lasted for less than 36 h and when the microorganism is not known.

Differences in supratentorial white matter diffusion after radiotherapy - new biomarker of normal brain tissue damage?

Abstract Introduction. Therapy-induced injury to normal brain tissue is a concern in the treatment of all types of brain tumours. The purpose of this study was to investigate if magnetic resonance diffusion tensor imaging (DTI) could serve as a potential biomarker for the assessment of radiation-induced long-term white matter injury. Material and methods. DTI- and T1-weighted images of the brain were obtained in 19 former radiotherapy patients [nine men and 10 women diagnosed with astrocytoma (4), pituitary adenoma (6), meningioma (8) and craniopharyngioma (1), average age 57.8 (range 35–71) years]. Average time from radiotherapy to DTI scan was 4.6 (range 2.0–7.1) years. NordicICE software (NIC) was used to calculate apparent diffusion coefficient maps (ADC-maps). The co-registration between T1 images and ADC-maps were done using the auto function in NIC. The co-registration between the T1 images and the patient dose plans were done using the auto function in the treatment planning system Eclipse from Varian. Regions of interest were drawn on the T1-weighted images in NIC based on isocurves from Eclipse. Data was analysed by t-test. Estimates are given with 95% CI. Results. A mean ADC difference of 4.6(0.3;8.9)× 10−5 mm2/s, p = 0.03 was found between paired white matter structures with a mean dose difference of 31.4 Gy. Comparing the ADC-values of the areas with highest dose from the paired data (dose > 33 Gy) with normal white matter (dose < 5 Gy) resulted in a mean dose difference of 44.1 Gy and a mean ADC difference of 7.87(3.15;12.60)× 10−5 mm2/s, p = 0.003. Following results were obtained when looking at differences between white matter mean ADC in average dose levels from 5 to 55 Gy in steps of 10 Gy with normal white matter mean ADC: 5 Gy; 1.91(−1.76;5.58)× 10−5 mm2/s, p = 0.29; 15 Gy; 5.81(1.53;10.11)× 10−5 mm2/s, p = 0.01; 25 Gy; 5.80(2.43;9.18)× 10−5 mm2/s, p = 0.002; 35 Gy; 5.93(2.89;8.97)× 10−5 mm2/s, p = 0.0007; 45 Gy; 4.32(−0.24;8.89)× 10−5 mm2/s, p = 0.06; 55 Gy; −4.04(−14.96;6.89)× 10−5 mm2/s, p = 0.39. Conclusion. The results indicate that the structural integrity of white matter, assessed by ADC-values based on DTI, undergoes changes after radiation therapy starting as early as total dose levels between 5 and 15 Gy.

Cripto-1 expression in glioblastoma multiforme

Human glioblastoma multiforme (GBM) is an aggressive cancer with a very poor prognosis. Cripto‐1 (CR‐1) has a key regulatory role in embryogenesis, while in adult tissue re‐expression of CR‐1 has been correlated to malignant progression in solid cancers of non‐neuronal origin. As CR‐1 expression has yet to be described in cerebral cancer and CR‐1 is regulated by signaling pathways dysregulated in GBM, we aimed to investigate CR‐1 in the context of expression in GBM. The study was performed using enzyme‐linked immunosorbent assay (ELISA), Western blotting, polymerase chain reaction (PCR) and immunohistochemistry to analyze the blood and tissue from 28 GBM and 4 low‐grade glioma patients. Within the patient cohort, we found high CR‐1 protein levels in blood plasma to significantly correlate with a shorter overall survival. We identified CR‐1 in different areas of GBM tissue, including perivascular tumor cells, and in endothelial cells. Collectively, our data suggest that CR‐1 could be a prognostic biomarker for GBM with the potential of being a therapeutic target.

Regional muscle tissue saturation is an indicator of global inadequate circulation during cardiopulmonary bypass : a randomized porcine study using muscle, intestinal and brain tissue metabolomics

Background: Muscle tissue saturation (StO2) measured with near-infrared spectroscopy has generally been considered a measurement of the tissue microcirculatory condition. However, we hypothesized that StO2 could be more regarded as a fast and reliable measure of global than of regional circulatory adequacy and tested this with muscle, intestinal and brain metabolomics at normal and two levels of low cardiopulmonary bypass blood flow rates in a porcine model. Methods: Twelve 80 kg pigs were connected to normothermic cardiopulmonary bypass with a blood flow of 60 mL/kg/min for one hour, reduced randomly to 47.5 mL/kg/min (Group I) or 35 mL/kg/min (Group II) for one hour followed by one hour of 60 mL/kg/min in both groups. Regional StO2 was measured continuously above the musculus gracilis (non-cannulated leg). Metabolomics were obtained by brain tissue oxygen monitoring system (Licox) measurements of the brain and microdialysis perfusate from the muscle, intestinal mucosa and brain. A non-parametric statistical method was used. Results: The systemic parameters showed profound systemic ischaemia during low CPB blood flow. StO2 did not change markedly in Group I, but in Group II, StO2 decreased immediately when blood flow was reduced and, furthermore, was not restored despite blood flow being normalized. Changes in the metabolomics from the muscle, colon and brain followed the changes in StO2. Conclusion: We found, in this experimental cardiopulmonary bypass model, that StO2 reacted rapidly when the systemic circulation became inadequate and, furthermore, reliably indicate insufficient global tissue perfusion even when the systemic circulation was restored after a period of systemic hypoperfusion.

Chronic cuff electrode recordings from walking Göttingen mini-pigs

We present data from cuff electrode recordings from a mixed sensory-/motor nerve as expressed during walking in chronically implanted Göttingen mini-pigs. Our results show that it is possible to filter out residual electromyographic interference and that the energy content of the resulting electroneurographic (ENG) signals modulate clearly with gait. The approach may be used to detect heel strike from cuff electrode measurements to control the timing of stimulation in implantable foot drop correction systems.

Barriers toward organ donation in a Danish University Hospital

In Denmark, organ donation‐rates are below the average in the western countries. We investigated the donor potential and identified barriers toward organ donation in a Danish university hospital.

Bilateral Wyburn-Mason Syndrome presenting as acute subarachnoid haemorrhage - a very rare congenital neurocutaneuos disorder

SummaryA 30 year old young male was admitted to our department after experiencing clincal symptoms of a subarachnoid haemorrhage. Imaging studies revealed large cerebral AVMs. Fundus examination of the left eye demonstrated a retinal racemose AVM almost completely covering the posterior pole of the eye. Wyburn-Mason syndrome is a very rare congenital neurocutaneuos disorder comprising of vascular malformations of the retina, ipsilateral cerebral AVMs and occasionally lesions in the oronasopharyngeal area. Subarachnoid haemorrhage associated with Wyburn-Mason syndrome has been described in only 5 patients in the literature since 1973. The finding of retinal AVMs should warrant cerebral imaging studies including CT- or MR-angiography.

Evaluation of intraoperative glove change in prevention of postoperative cerebrospinal fluid shunt infections, and the predictors of shunt infection

Abstract Background: We have previously suggested that surgical gloves could be a possible means for transferring microorganisms from skin flora to shunt material during surgery. The objectives of this study were to examine (1) whether the rate of shunt infections was reduced after introducing intraoperative glove change before handling the shunt material; (2) clinical presentation of shunt infections, microbiological data, and treatment management; and (3) predictors of shunt infections. Methods: A retrospective study of 432 shunt operations in 295 adults was undertaken over a 7-year period. Study population consisted of two groups: Group A without intraoperative glove change (2003–2006), and Group B with change of the outer pair of the initial double gloves before handling the shunt material (2006–2009). The results were compared at 6- and 12-month postoperatively. A binary logistic regression was performed to determine predictors of shunt infections. Results: Overall, 46 (10.6%) infection episodes occurred in 40 (13.6%) patients. Main symptoms were fever, abdominal pain and altered mental status. Propionibacterium acnes was the frequently isolated microorganism, followed by Staphylococcus species. The infection rate was reduced only moderately from 11.8% in Group A to 9.8% in Group B (p = .472). Patients with subarachnoid haemorrhage were more likely to experience shunt infections (17.9%), compared to patients with normal pressure hydrocephalus (5.9%). An increased likelihood of shunt infections for the increased number of subsequent shunt revisions (p = .030) and a trend towards prior history of shunt infections (p = .118) was seen. After adjusting for various covariates, a decreased likelihood of shunt infections for intraoperative glove change was seen at 6-month follow-up for first-time shunt insertion (p = .050). Conclusion: Intraoperative glove change does not significantly reduce the risk of shunt infection. However, it seems to reduce the infection rate within 6 months in patients undergoing first-time shunt insertion only.

Presurgical functional magnetic resonance imaging in patients with brain tumors

Background Clinical functional magnetic resonance imaging (fMRI) is still an upcoming diagnostic tool because it is time-consuming to perform the post-scan calculations and interpretations. A standardized and easily used method for the clinical assessment of fMRI scans could decrease the workload and make fMRI more attractive for clinical use. Purpose To evaluate a standardized clinical approach for distance measurement between benign brain tumors and eloquent cortex in terms of the ability to predict pre- and postoperative neurological deficits after intraoperative neuronavigation-assisted surgery. Material and Methods A retrospective study of 34 patients. The fMRI data were reanalyzed using a standardized distance measurement procedure combining data from both fMRI and three-dimensional T1 MRI scans. The pre- and postoperative neurological status of each patient was obtained from hospital records. Data analysis was performed using logistic regression analysis to determine whether the distance measured between the tumor margin and fMRI activity could serve as a predictor for neurological deficits. Results An odds ratio of 0.89 mm–1 (P = 0.03) was found between the risk of preoperative neurological motor deficits and the tumor-fMRI distance. An odds ratio of 0.82 mm–1 (P = 0.04) was found between the risk of additional postoperative neurological motor deficits and the tumor-fMRI distance. The tumor was radically removed in 10 cases; five patients experienced additional postoperative motor deficits (tumor-fMRI distance <18 mm) and five did not (tumor-fMRI distance >18 mm) (P = 0.008). Conclusion This study indicates that the distance measured between the tumor margin and fMRI activation could serve as a valuable predictor of neurological motor deficits.