Stefan Schob

Distance to Thrombus in Acute Middle Cerebral Artery Occlusion A Predictor of Outcome After Intravenous Thrombolysis for Acute Ischemic Stroke

Background and Purpose— In patients with acute middle cerebral artery (MCA) stroke, therapeutic decisions are influenced by the location of the occlusion. This study aimed to analyze clinical outcomes in patients with acute ischemic MCA stroke treated with systemic intravenous thrombolysis (IVT) using recombinant tissue plasminogen activator, according to the location of the occlusion. Methods— Of 621 patients screened, 136 with acute stroke and MCA occlusion confirmed by CT angiography were retrospectively included in this study. The distance from the carotid T to the thrombus (DT) on coronal maximum intensity projection images and the thrombus length were measured. The correlation between DT and the modified Rankin Scale score at 90 days was analyzed. Results— DT was an independent predictor of clinical outcome in stroke patients treated with IVT. A long DT was significantly correlated with a good clinical outcome (modified Rankin Scale score at 90 days ⩽2). A poor clinical outcome was exponentially more likely than a good outcome when the DT was <16 mm (P<0.001). The thrombus length was not correlated with the modified Rankin Scale score at 90 days. A long thrombus (>8 mm) occurred significantly more often in the proximal MCA than the distal MCA (P<0.001). Conclusion— DT is an independent predictor of clinical outcome in patients with acute MCA occlusion treated with IVT. In acute stroke with MCA occlusion confirmed by CT angiography and DT <16 mm, the likelihood of a good clinical outcome after treatment with IVT was exponentially <50%. This might warrant the evaluation of other therapy forms than IVT in patients with proximal MCA occlusion.

The Detection of Surfactant Proteins A, B, C and D in the Human Brain and Their Regulation in Cerebral Infarction, Autoimmune Conditions and Infections of the CNS

Surfactant proteins (SP) have been studied intensively in the respiratory system. Surfactant protein A and surfactant protein D are proteins belonging to the family of collectins each playing a major role in the innate immune system. The ability of surfactant protein A and surfactant protein D to bind various pathogens and facilitate their elimination has been described in a vast number of studies. Surfactant proteins are very important in modulating the hosts inflammatory response and participate in the clearance of apoptotic cells. Surfactant protein B and surfactant protein C are proteins responsible for lowering the surface tension in the lungs. The aim of this study was an investigation of expression of surfactant proteins in the central nervous system to assess their specific distribution patterns. The second aim was to quantify surfactant proteins in cerebrospinal fluid of healthy subjects compared to patients suffering from different neuropathologies. The expression of mRNA for the surfactant proteins was analyzed with RT-PCR done with samples from different parts of the human brain. The production of the surfactant proteins in the brain was verified using immunohistochemistry and Western blot. The concentrations of the surfactant proteins in cerebrospinal fluid from healthy subjects and patients suffering from neuropathologic conditions were quantified using ELISA. Our results revealed that surfactant proteins are present in the central nervous system and that the concentrations of one or more surfactant proteins in healthy subjects differed significantly from those of patients affected by central autoimmune processes, CNS infections or cerebral infarction. Based on the localization of the surfactant proteins in the brain, their different levels in normal versus pathologic samples of cerebrospinal fluid and their well-known functions in the lungs, it appears that the surfactant proteins may play roles in host defense of the brain, facilitation of cerebrospinal fluid secretion and maintenance of the latters rheological properties.

Histogram Analysis of Diffusion Weighted Imaging at 3T is Useful for Prediction of Lymphatic Metastatic Spread, Proliferative Activity, and Cellularity in Thyroid Cancer

Pre-surgical diffusion weighted imaging (DWI) is increasingly important in the context of thyroid cancer for identification of the optimal treatment strategy. It has exemplarily been shown that DWI at 3T can distinguish undifferentiated from well-differentiated thyroid carcinoma, which has decisive implications for the magnitude of surgery. This study used DWI histogram analysis of whole tumor apparent diffusion coefficient (ADC) maps. The primary aim was to discriminate thyroid carcinomas which had already gained the capacity to metastasize lymphatically from those not yet being able to spread via the lymphatic system. The secondary aim was to reflect prognostically important tumor-biological features like cellularity and proliferative activity with ADC histogram analysis. Fifteen patients with follicular-cell derived thyroid cancer were enrolled. Lymph node status, extent of infiltration of surrounding tissue, and Ki-67 and p53 expression were assessed in these patients. DWI was obtained in a 3T system using b values of 0, 400, and 800 s/mm2. Whole tumor ADC volumes were analyzed using a histogram-based approach. Several ADC parameters showed significant correlations with immunohistopathological parameters. Most importantly, ADC histogram skewness and ADC histogram kurtosis were able to differentiate between nodal negative and nodal positive thyroid carcinoma. Conclusions: histogram analysis of whole ADC tumor volumes has the potential to provide valuable information on tumor biology in thyroid carcinoma. However, further studies are warranted.

Adult long-term health-related quality of life of congenital hydrocephalus patients.

OBJECT Congenital hydrocephalus has a major impact on the lives of patients and their relatives, as well as their long-term neurological development and social integration. The aim of this study was to assess the self-reported health-related quality of life (HRQOL) of patients after reaching adulthood. METHODS A total of 31 patients who required CSF shunt treatment for congenital hydrocephalus within the 1st year of life (between 1963 and 1987) agreed to undergo a structured SF-36 self-assessment. An age-matched German standard cohort was used as control. Additional parameters of surgical, social, and global neurological outcome were analyzed. The mean patient age was 35 years (range 26-51 years, 13 females and 18 males). Hydrocephalus etiologies were posthemorrhagic hydrocephalus (n = 9), postinfectious hydrocephalus (n = 5), aqueductal stenosis (n = 10), myelomeningocele (n = 2), and unknown cause (n = 5). RESULTS The mean modified Rankin Scale score was 1.6 (range 0-4). Hydrocephalic patients achieved lower scores for the SF-36 items physical functioning (70.5 vs. 93.5, p < 0.05), physical role functioning (74.2 vs. 88.3, p < 0.05), and general health perceptions (64.5 vs. 72.3, p < 0.05). Emotional, social role functioning, and mental health items did not differ between the groups. Assessment of vitality and pain resulted in a trend to worse values. Whereas the Physical Component Summary score was lower (46.1 vs. 54.3, p < 0.05), the Mental Component Summary score was not significantly different (50.2 vs. 48.7, p = 0.3). There was neither a statistically significant difference between subgroups of different etiologies nor an association with the number of subsequent hydrocephalus-related surgeries. CONCLUSIONS Adult HRQOL for patients with congenital hydrocephalus appears to be similar to that for healthy con with regard to mental health and social functioning aspects. Physical impairment is a predominant factor of compro quality of life.

CXCR4 and CXCR7 Mediate TFF3-Induced Cell Migration Independently From the ERK1/2 Signaling Pathway.

PURPOSE Trefoil factor family (TFF) peptides, and in particular TFF3, are characteristic secretory products of mucous epithelia that promote antiapoptosis, epithelial migration, restitution, and wound healing. For a long time, a receptor for TFF3 had not yet been identified. However, the chemokine receptor CXCR4 has been described as a low affinity receptor for TFF2. Additionally, CXCR7, which is able to heterodimerize with CXCR4, has also been discussed as a potential TFF2 receptor. Since there are distinct structural similarities between the three known TFF peptides, this study evaluated whether CXCR4 and CXCR7 may also act as putative TFF3 receptors. METHODS We evaluated the expression of both CXCR4 and CXCR7 in samples of human ocular surface tissues and cell lines, using RT-PCR, immunohistochemistry, and Western blot analysis. Furthermore, we studied possible binding interactions between TFF3 and the receptor proteins in an x-ray structure-based modeling system. Functional studies of TFF3-CXCR4/CXCR7 interaction were accomplished by cell culture-based migration assays, flow cytometry, and evaluation of activation of the mitogen-activated protein (MAP) kinase signaling cascade. RESULTS We detected both receptors at mRNA and protein level in all analyzed ocular surface tissues, and in lesser amount in ocular surface cell lines. X-ray structure-based modeling revealed CXCR4 and CXCR7 dimers as possible binding partners to TFF3. Cell culture-based assays revealed enhanced cell migration under TFF3 stimulation in a conjunctival epithelial cell line, which was completely suppressed by blocking CXCR4 and/or CXCR7. Flow cytometry showed increased proliferation rates after TFF3 treatment, while blocking both receptors had no effect on this increase. Trefoil factor family 3 also activated the MAP kinase signaling cascade independently from receptor activity. CONCLUSIONS Dimers CXCR4 and CXCR7 are involved in TFF3-dependent activation of cell migration, but not cell proliferation. The ERK1/2 pathway is activated in the process, but not influenced by CXCR4 or CXCR7. These results implicate a dependence of TFF3 activity as to cell migration on the chemokine receptors CXCR4 and CXCR7 at the ocular surface.

Whole lesion histogram analysis of meningiomas derived from ADC values. Correlation with several cellularity parameters, proliferation index KI 67, nucleic content, and membrane permeability

PURPOSE To analyze several histopathological features and their possible correlations with whole lesion histogram analysis derived from ADC maps in meningioma. MATERIALS AND METHODS The retrospective study involved 36 patients with primary meningiomas. For every tumor, the following histogram analysis parameters of apparent diffusion coefficient (ADC) were calculated: ADCmean, ADCmax, ADCmin, ADCmedian, ADCmode, ADC percentiles: P10, P25, P75, P90, as well kurtosis, skewness, and entropy. All measures were performed by two radiologists. Proliferation index KI 67, minimal, maximal and mean cell count, total nucleic area, and expression of water channel aquaporin 4 (AQP4) were estimated. Spearmans correlation coefficient was used to analyze associations between investigated parameters. RESULTS A perfect interobserver agreement for all ADC values (0.84-0.97) was identified. All ADC values correlated inversely with tumor cellularity with the strongest correlation between P10, P25 and mean cell count (-0.558). KI 67 correlated inversely with all ADC values except ADCmin. ADC parameters did not correlate with total nucleic area. All ADC values correlated statistically significant with expression of AQP4. CONCLUSIONS ADC histogram analysis is a valid method with an excellent interobserver agreement. Cellularity parameters and proliferation potential are associated with different ADC values. Membrane permeability may play a greater role for water diffusion than cell count and proliferation activity.

Apparent diffusion coefficient (ADC) does not correlate with different serological parameters in myositis and myopathy

Background Magnetic resonance imaging (MRI) is widely used in several muscle disorders. Diffusion-weighted imaging (DWI) is an imaging modality, which can reflect microstructural tissue composition. The apparent diffusion coefficient (ADC) is used to quantify the random motion of water molecules in tissue. Purpose To investigate ADC values in patients with myositis and non-inflammatory myopathy and to analyze possible associations between ADC and laboratory parameters in these patients. Material and Methods Overall, 17 patients with several myositis entities, eight patients with non-inflammatory myopathies, and nine patients without muscle disorder as a control group were included in the study (mean age = 55.3 ± 14.3 years). The diagnosis was confirmed by histopathology in every case. DWI was obtained in a 1.5-T scanner using two b-values: 0 and 1000 s/mm2. In all patients, the blood sample was acquired within three days to the MRI. The following serological parameters were estimated: C-reactive protein, lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, creatine kinase, and myoglobine. Results The estimated mean ADC value for the myositis group was 1.89 ± 0.37 × 10–3 mm2/s and for the non-inflammatory myopathy group was 1.79 ± 0.33 × 10–3 mm2/s, respectively. The mean ADC values (1.15 ± 0.37 × 10–3 mm2/s) were significantly higher to unaffected muscles (vs. myositis P = 0.0002 and vs. myopathy P = 0.0021). There were no significant correlations between serological parameters and ADC values. Conclusion Affected muscles showed statistically significantly higher ADC values than normal muscles. No linear correlations between ADC and serological parameters were identified.

MRI Texture Analysis Reflects Histopathology Parameters in Thyroid Cancer – A First Preliminary Study

OBJECT: Thyroid cancer represents the most frequent malignancy of the endocrine system with an increasing incidence worldwide. Novel imaging techniques are able to further characterize tumors and even predict histopathology features. Texture analysis is an emergent imaging technique to extract extensive data from an radiology images. The present study was therefore conducted to identify possible associations between texture analysis and histopathology parameters in thyroid cancer. METHODS: The radiological database was retrospectively reviewed for thyroid carcinoma. Overall, 13 patients (3 females, 23.1%) with a mean age of 61.6 years were identified. The MaZda program was used for texture analysis. The T1-precontrast and T2-weighted images were analyzed and overall 279 texture feature for each sequence was investigated. For every patient cell count, Ki67-index and p53 count were investigated. RESULTS: Several significant correlations between texture features and histopathology were identified. Regarding T1-weighted images, S(0;1)Sum Averg correlated the most with cell count (r = 0.82). An inverse correlations with S(5;0)AngScMom, S(5;0)DifVarnc S(5;0), DiffEntrp and GrNonZeros (r = −0.69, −0.66, −0.69 and −0.63, respectively) was also identified. For T2-weighted images, Variance with r = 0.63 was the highest coefficient, WavEnLL_S3 correlated inversely with cell count (r = −0.57). WavEnLL_S2 derived from T1-weighted images was the highest coefficient r = −0.80, S(0;5)SumVarnc was positively with r = 0.74. Regarding T2-weighted images WavEnHL_s-1 was inverse correlated with Ki67 index (r = −0.77). S(1;0)Correlat was with r = 0.75 the best correlation with Ki67 index. For T1-weighed images S(5;0)SumofSqs was the best with r = 0.65 with p53 count. For T2-weighted images S(1;−1)SumEntrp was the inverse correlation with r = −0.72, whereas S(0;4)AngScMom correlated positively with r = 0.63. CONCLUSIONS: MRI texture analysis derived from conventional sequences reflects histopathology features in thyroid cancer. This technique might be a novel noninvasive modality to further characterize thyroid cancer in clinical oncology.

Systemic air embolism after endoscopy without vessel injury - A summary of reported cases.

INTRODUCTION Systemic air embolism (SAE) is a rare but serious complication following endoscopic procedures. It may occur with or without direct vessel injury. The aim of this work is to review cases of SAE following endoscopy without proven vessel injury. METHODS In this systematic review PubMed database was screened for SAE following endoscopy from 1990 to 2015. Only cases without proven major vessel injury were included in the analysis. Including one case of SAE after colonoscopy from our hospital the analysis comprised 40 cases. RESULTS 60% of patients underwent ERCP, 33% gastroscopy and the remaining 7% other endoscopic procedures. Among patients suffering from SAE the majority had cerebral embolism (73%). In 46% of documented echocardiography a patent foramen ovale (PFO) has been confirmed as mechanism of paradoxical air embolism. Therapeutic approaches comprised most frequently hyperbaric oxygenation. In 35% of cases advanced life support was necessary whereas only 55% of patients survived SAE in total. CONCLUSION SAE is a serious complication of endoscopic procedures with high morbidity and mortality. In patients with present PFO high awareness should be paid to informed consent for the risk of SAE, especially stroke. Cautiousness with sedation is necessary in those patients not to delay clinical recognition of neurological SAE symptoms.

Stent-Assisted Coiling of Ruptured and Incidental Aneurysms of the Intracranial Circulation Using Moderately Flow-Redirecting, Braided Leo Stents—Initial Experience in 39 Patients

Background Flow diversion (FD)—a young technique using stents with highly increased surface coverage—was introduced to treat complex aneurysms without intra-aneurysmal material placement and has amended the spectrum of endovascular techniques such as stent-assisted coil occlusion considerably. However, ischemic complications, a common side effect in FD, occur more frequently compared with the conventional endovascular approaches and certainly limit the indication of this technique. Our study aimed to investigate the feasibility and efficacy of stent-assisted coiling using low profile self-expandable stents, which exhibit only moderate flow-redirecting properties and therefore represent a combination of hemodynamic endovascular and occlusive endosaccular therapy. Materials and methods 39 Patients were included in our retrospective study. Occlusion rates were assessed 6 months after the procedure in a total of 27 cases using the Raymond scale. Results Complete occlusion (Raymond I) was achieved in 24/27 aneurysms. Small neck remnants (Raymond II) were evident in 3/27 aneurysms. There were no cases with sac remnant or complete persistence of aneurysmal filling (Raymond III and IV). Conclusion Our study demonstrates interventional treatment of intracranial aneurysms using flow-redirecting stent-assisted coiling to be technically feasible and highly effective in aneurysmal occlusion. We believe that this approach is outstanding in the prevention of long-term aneurysmal reperfusion and exhibits a more acceptable risk profile than highly efficient FD techniques.