Cervical cord and ventricle affection in neuromyelitis optica.

OBJECTIVES: Cervical cord involvement is common in neuromyelitis optica (NMO) and multiple sclerosis (MS), but its impact on disability in NMO has rarely been studied. Recent publications on NMO examined the periventricular system, areas of high aquaporin-4 expression, but not yet by using ventricle volumetry. PURPOSE: To compare cervical cord atrophy, ventricular widening, and supra- and infratentorial brain measures between NMO and MS, and study their impact on clinical disability. METHODS: Magnet resonance imaging-based volumetry of upper cervical cord, third and fourth lateral ventricles, grey matter, white matter, brainstem, cerebellum and clinical status of 18 NMO and 20 MS patients, was compared between the groups and with 26 healthy controls. Patterns of ventricular widening relative to healthy controls were inspected by voxel-based morphometry of the cerebrospinal fluid. RESULTS: Cervical cord atrophy was similar in NMO and MS (75.2 ± 10.0 mm2 , respectively, 76.5 ± 9.5 mm2 vs 84.1 ± 8.6 mm2 in controls).Third ventricle increase in both groups, and specific fourth ventricle widening in MS were detected. Patient groups differed in third to fourth ventricle ratio (P = 0.002). In NMO, white matter correlated inversely with the affected cord segments (P = 0.001) and with cervical cord area (P = 0.043). The disability status was explained by cervical cord area and third ventricle volume (R2 =0.524) in NMO, and by grey matter and fourth ventricle volume (R2 =0.565) in MS. CONCLUSION: Cervical cord atrophy and third ventricular enlargement are both clinically relevant in NMO. Third and fourth ventricle volumetry shows differences between NMO and MS regarding the involvement of periventricular structures.

A morphometric cadaver study of the anterior lumbar epidural space.

INTRODUCTION: Free disc fragments end often up in the concavity of the anterior epidural space. This space consists of two compartments. The discrepancy between the impressive magnetic resonance imaging findings, clinical symptoms in patients and the problem of treatment options led us to the anatomical determination of anterior epidural space volumes. MATERIALS AND METHODS: For the first time, the left and right anterior epidural volume between the peridural membrane and the posterior concavity of the lumbar vertebral bodies L3-S1 were determined for each segment. A CT scan and a polyester resin injection were used for the in vitro measurements. RESULTS: The volumes determined in human cadavers using this method ranged from 0.23 ccm for L3 to 0.34 ccm for L5. The CT concavity volume determination showed this increase in volume from cranial to caudal, as well. CONCLUSION: This volume is large enough to hold average-sized slipped discs without causing neurological deficits. A better understanding of the anterior epidural space may allow a better distinction of patient treatment options.

[Prevention and management of postoperative complications in pancreatic surgery]. / Prävention und Management von postoperativen Komplikationen in der Pankreaschirurgie.

During the last decades mortality after pancreatic surgery has decreased. Nevertheless, morbidity still remains at a high level. It is important to differentiate between pancreatic head resection and distal pancreatectomy. The complication rates of both procedures are high, however the need for intervention to manage perilous complications is higher after pancreaticoduodenectomy. The main complications after pancreatic surgery are delayed gastric emptying (DGE), pancreatic fistula, anastomotic leakage and bleeding. The current literature on the different techniques of pancreatic anastomosis and pancreatic remnant closure, respectively, does not show consistent results or an advantage for a particular technique. The same is true for the perioperative use of somatostatin and its analogues for the prevention of complications. It is widely agreed that the smooth texture of the pancreas and a small pancreatic duct < 3 mm are risk factors for pancreatic leakage or fistula. Today, the trend is more for conservative or interventional therapy for pancreatic fistulas or intraabdominal collections with, e. g., persisting intraoperative drain, TPN, somatostatin therapy or CT-controlled drainage. The opinions about the optimal treatment of the dreaded postoperative bleeding differ significantly in the surgical community. There are early and late bleedings and the management varies from endoscopical treatment or angiographic coiling / stenting to revision. Nevertheless, every bleeding is accompanied with high mortality. Here we present a review of literature and demonstrate the various strategies for the management of complications.

MR venography in the detection of pelvic venous congestion.

PURPOSE: To investigate the feasibility of using magnetic resonance venography (MRV) to detect pelvic venous congestion (PVC). METHODS: A prospective study of 23 female patients with signs and symptoms of PVC, who underwent duplex sonography, MRV and phlebography (P). Examinations were interpreted in a blinded fashion. Visualization of venous anatomy, presence of venous incompetence and congestion grade were evaluated. Sensitivity and specificity of MRV using P as reference were calculated. RESULTS: MRV agreed with P in 96% (Cohen-K-value 0.646) and in 70% (K 0.555) of the cases respectively in the venous anatomy and congestion grade. Sensitivity and specificity of MRV were 88% and 67% for ovarian veins, 100% and 38% for hypogastric veins and 91% and 42% for the pelvic plexus. CONCLUSIONS: In this prospective study MRV showed high sensitivity in the evaluation of patients with suspected PVC. Routine use of this diagnostic method requires further studies in larger patient cohorts.

Brain structural alterations associated with dysfunctional cognitive control of pain in patients with low back pain.

BACKGROUND: Recent evidence has shown that chronic back pain (CBP) can lead to functional alterations in the circuitry underlying the cognitive control of pain. Thought suppression (TS) is a common type of cognitive control of pain. Previous research has shown that TS has paradoxical effects that may increase the awareness of pain. Pain-related TS may also increase individuals' attention to pain, which may also increase pain sensation, but thus far, the relationship between pain-related TS and structural brain alterations is unknown. METHODS: In this study, we investigated a group of 30 patients 6 months after lumbar disc surgery by applying voxel-based morphometry (VBM) to identify brain regions correlated with TS scores. RESULTS: Since pain-related TS has been positively correlated with depression, all calculations were controlled for depression and age. VBM revealed a negative correlation between the TS score and regional grey matter volume (GMV) in the left superior temporal gyrus (LSTG) and the left middle temporal gyrus (L MTG), which is part of the left temporoparietal junction (L TPJ). In addition, a mediation analysis revealed a significant mediation effect of the pain-related TS on the association between GMV of the left TPJ and reported pain intensity in the last 7 days. CONCLUSIONS: These findings are consistent with previous research on the dysfunctional cognitive control of pain and may therefore provide potential insights into the neural substrates of obstructive cognitive control in chronic low back pain, with a special emphasis on pain-related TS. SIGNIFICANCE: The link between pain-related thought suppression and brain morphology may provide a new perspective on the understanding of cognitive control of pain in chronic low back pain, which may help improve cognitive behavioural therapy.

Diffusion tensor imaging-based fractional anisotropy quantification in the corticospinal tract of patients with amyotrophic lateral sclerosis using a probabilistic mixture model.

BACKGROUND AND PURPOSE: In amyotrophic lateral sclerosis (ALS), fiber degeneration within the corticospinal tract (CST) can be quantified by diffusion tensor imaging (DTI) as an indirect marker of upper motor neuron involvement. A new method of measuring quantitative DTI parameters using a probabilistic mixture model for fiber tissue and background in the corticospinal tract of patients with ALS is evaluated. MATERIALS AND METHODS: Axial echo-planar imaging (EPI) DTI datasets (6 gradient directions, 10 repetitions) were acquired for 10 patients and 20 healthy control subjects. The diffusion tensor was visualized in a multiplanar viewer using a unique color coding method. Pure fiber tissue inside a region is separated from background and mixture voxels using a probabilistic mixture model. This allows for a reduction of errors as a result of partial volume effects and measurement variability. RESULTS: Fractional anisotropy (FA) was measured within the CST at levels ranging from internal capsule to pons. Mean coefficients of variation of intrarater, scan-rescan, and inter-rater reproducibility were 2.4%, 3.0%, and 5.7%, respectively. Optimal measurement positions along the CST with respect to minimum variability and maximum difference between patients and healthy subjects were identified in the caudal half of the internal capsule. Moreover, a negative correlation between the age-corrected FA and the disease duration but not the ALS Severity scale score was found. CONCLUSION: The new software for fiber integrity quantification is suited to assess FA in the corticospinal tract with high reproducibility. Thus, this tool can be useful in future studies for monitoring disease status and potential treatment efficiency.

Is initial success of thrombolytic therapy with rt-PA in patients with lower limb ischemia durable? A long-term follow-up series.

BACKGROUND: Catheter-directed intraarterial thrombolytic therapy with rt-PA has been established as an alternative to surgery in selected patients with lower limb ischemia. The purpose of this study is to evaluate its long-term results and to try to identify patient variables influencing outcome. PATIENTS AND METHODS: The results of thrombolytic treatment for acute or subacute lower limb ischemia in 82 patients (51 male, 31 female) were retrospectively analysed. Clinical data (time of symptoms onset, clinical stage, type of affected vessel, anatomical localisation) as well as comorbidities were recorded. The success rate of thrombolysis as well as the incidence of adverse events was evaluated. Patients with initial success were followed up after a median of 52,5 months. RESULTS: Thrombolytic therapy was successful in 67 cases (82%). An additional endovascular or surgical procedure was necessary in 39 of these patients (48%). The overall bleeding rate was 18% and the mortality and major amputation rate was 1%. 42 patients with early clinical success were available for follow-up. 34 of them (81%) were free of ischemic symptoms and the overall limb salvage rate was 96%. We could not identify factors significantly influencing early or long-term results, although there was a trend towards better results in patients with acute ischemia and in patients with occluded native arteries. CONCLUSIONS: Intraarterial local thrombolytic therapy has a relatively high initial success rate in selected patients with lower limb ischemia, but is associated with a significant number of bleeding complications. Furthermore, additional procedures are required in almost half the patients. Initial success is durable at the long-term in the majority of cases. Better selection of patients and refinements of the thrombolytic therapy might help to further improve results and lower the bleeding complications.

Daphnia behavioural responses to taste and odour compounds: ecological significance and application as an inline treatment plant monitoring tool.

Continuous monitoring of volatile organic compounds (VOC) in raw water is highly desirable for taste and odour management, but in most treatment plants this capacity is lacking. We used a bbe Daphnia toximeter installed in the Zurich water treatment plant to determine if Daphnia magna could be used to monitor odour compounds in source-water. Trace levels of two widely distributed biogenic VOCs in freshwater: P-cyclocitral and 2(E),4(E),7(Z)-decatrienal were added to the raw water inflow to chambers containing test animals and their behaviour was recorded using a high resolution camera. We observed that each compound elicited a marked short-term increase in Daphnia swimming velocity, but the effect was brief and an acclimation to the compounds was observed after a time period or with repeated additions. The results demonstrate that the toximeter has considerable potential as a tool to monitor certain VOCs in water, and that Daphnia perceive and react to 2(E),4(E),7(Z)-decatrienal and P-cyclocitral at concentrations between 2.5 and 25 microM.

Characterization of a [Ca2+]i-dependent current in human atrial and ventricular cardiomyocytes in the absence of Na+ and K+.

OBJECTIVES: In situations of [Ca2+]i-overload, arrhythmias are believed to be triggered by delayed afterdepolarizations, which are generated by a transient inward current ITI. This study was designed to examine [Ca2+]i-dependent membrane currents in the absence of the Na+/Ca(2+)-exchanger as possible contributors to ITI in human cardiac cells. METHODS: The whole cell voltage clamp technique was used for electrophysiological measurements in human atrial and ventricular cardiomyocytes. [Ca2+]i-measurements were performed using the fluorescent Ca(2+)-indicator fura-2. All solutions were Na(+)-free. Voltage-independent [Ca2+]i-transients were elicited by rapid caffeine applications. RESULTS: In atrial myocytes, caffeine induced a transient membrane current in the absence of Na+ and K+. This current could be suppressed by internal EGTA (10 mM). Cl- did not contribute to this current. Experiments with different cations suggested non-selectivity for Cs+ and Li+, whereas N-methyl-D-glucamine appeared to be impermeable. Voltage ramps indicated a linear current-voltage relation in the range of +80 to -80 mV. Fluorescence measurements revealed a dissociation between the time courses of current and bulk [Ca2+]i-signal. In ventricular cardiomyocytes, caffeine failed to induce transient currents in 54 cells from 22 different patients with or without terminal heart failure. CONCLUSIONS: In human atrial cardiomyocytes, a [Ca2+]i-dependent nonspecific cation channel is expressed and may contribute to triggered arrhythmias in situations of [Ca2+]i-overload. No evidence could be found for the existence of a [Ca2+]i-dependent chloride current in atrial cells. In ventricular cells, neither a [Ca2+]i-dependent nonspecific cation channel nor a [Ca2+]i-dependent chloride channel seems to be expressed. Possible delayed afterdepolarizations in human ventricular myocardium might therefore be carried by the Na+/Ca(2+)-exchanger alone.

Cervical cord area is associated with infratentorial grey and white matter volume predominantly in relapsing-remitting multiple sclerosis: A study using semi-automated cord volumetry and voxel-based morphometry.

BACKGROUND AND PURPOSE: Atrophy of the brain and the upper cervical cord, which both have major impact on the severity of clinical symptoms in multiple sclerosis (MS), may be interrelated by neuraxonal degeneration. Aiming to identify possible spatially remote effects of neuraxonal brain damage on spinal cord atrophy, we studied regional and global brain volumes and the upper cervical cord area (UCCA) in a large group of MS patients and a healthy control group. METHODS: In a group of 132 MS patients (71 relapsing-remitting MS; 61 secondary progressive MS; median [range] of EDSS: 5 [0-7], respectively 6 [2-8.5] and mean±standard deviation of age/disease duration: 37±11 years/6.7±6.3 years; respectively: 49±8 years/14.5±8.0 years) and 45 healthy subjects UCCA, regional and global brain volumes, and brain lesion load were assessed. Associations between MRI results and clinical parameters in the entire cohort and differentiated according to MS-subtype were investigated using t-tests, partial correlation analyses, voxel-based morphometry and statistical parametric mapping. RESULTS: Exclusively in RRMS, a significant positive correlation of UCCA with cerebellar cortical grey matter (GM) in the vermis and with regional white matter volume in the entire brainstem, corresponding to the corticospinal tracts, was detected. Although SPMS patients were considerably more affected by disability and decrease of UCCA (RRMS:75.2±10.4 mm(2); SPMS: 66.0±11.8 mm(2),controls: 84.5±8.7mm(2)), brain grey matter (RRMS:585.8±53.6 ml; SPMS: 528.2±61.5 ml, controls: 608.7±48.1 ml) and total brain volume (RRMS:1162.9±41.8 ml; SPMS: 1117.9±51.2 ml, controls: 1194.1±19.5 ml) than RRMS patients, significant positive associations in this group were found only between UCCA and a cluster of white matter in the medulla, but not in grey matter. CONCLUSION: Cervical cord and brain atrophy were present in both, RRMS and even more severe in SPMS. Still, spatial associations between cervical cord area and remote cerebellar and brainstem volume, possibly driven by neuraxonal degeneration, were detected mostly in RRMS patients with predominantly short disease durations. Future longitudinal studies may elucidate the interplay between affection of spinal cord and infratentorial structures in MS, and contribute to the understanding of the conversion processes from relapsing-remitting to secondary progressive MS.

NH4+ utilization and regeneration rates in freshwater lakes determined by GC-MS of derivatised dihydroindophenol.

A new gas chromatographic-mass spectrometric method was established that is applicable for the determination of NH4+ utilization and regeneration rates in freshwater. Hollow-fibre modules were used to stop the biogenic nitrogen-fluxes by separating the particulate from the dissolved matter. Incubations were performed in Tedlar bags (polyvinylfluoride), which enabled repeated sample removals through Teflon tubes, making the calculation of nitrogen-fluxes in accordance to Blackburn and Caperon much more reliable. The Berthelot reaction was performed with ammonium and a fragment ion (base peak) of tris-(trifluoroacetyl) 4,4'-dihydroxydiphenylamine was used to determine the at% excess 15N by gas chromatography-mass spectrometry. Nitrogen-flux measurements were made in the epilimnion of the deep, stratified, mesotrophic Lake Zürich, in which the cyanobacterium Planktothrix rubescens was the dominating photoautotrophic micro-organism. The size fraction <20 microm that consisted of heterotrophic bacterioplankton and nanoflagellates, and photoautotrophic pico- and nanoplankton accounted only for a minor part of the ammonium utilization (<25%) and regeneration (< or =25%) rates, whereas the size fraction >20 microm which primarily consisted of Planktothrix rubescens was responsible for the major part. In the eutrophic Lake Au, which is connected to Lake Zürich through a canal, utilization and regeneration rates as high as 700 and 482 nM h(-1) were measured.

Impact of apomorphine on BOLD signal during movement in normals.

Our group investigated modulatory effects of apomorphine on cerebral activation patterns during finger tapping movements in six healthy right-handed volunteers using an established fMRI protocol. Apomorphine application disclosed a reduction of cerebral activation to the contralateral precentral and postcentral gyrus and ipsilateral cerebellum, with a prominent net reduction of BOLD signal in cerebellar areas. These findings contradict those of similar studies performed on dopaminergic function and Parkinson's disease (PD), which predominantly found augmentation of cerebral activation patterns in normal volunteers and PD patients after dopaminergic stimulation. One conceivable explanation for our singular results would be preferred binding of apomorphine to presynaptic dopaminergic receptors, leading to inhibition of endogenous dopamine release and resultant diminished dopaminergic stimulation, reflected in diminished cerebral activation patterns. These findings warrant future consideration and further investigation of possible central inhibitory effects of dopaminergic therapy in functional imaging studies of the dopaminergic system in general and PD in particular.

Diagnosis and monitoring of middle cerebral artery occlusion with contrast-enhanced transcranial color-coded real-time sonography in patients with inadequate acoustic bone windows.

Transcranial color-coded real-time sonography (TCCS) is an emerging diagnostic technique that allows noninvasive imaging of intracranial vessels within parenchymal structures. However, in some patients, transcranial ultrasound is particularly hindered by insufficient ultrasound penetration through the temporal bone. The present study evaluates whether or not application of an echo-contrast agent in ultrasound-refractory patients with middle cerebral artery (MCA) trunk occlusion enhances image acquisition enough to yield accurate diagnoses. Contrast-enhanced (CE) TCCS examinations, computed tomography scans and angiographic studies were performed in 20 patients with clinical symptoms suggestive of MCA occlusion within 12 h of the onset of symptoms. For comparison, 20 control persons without history or clinical signs for cerebrovascular diseases were examined using CE-TCCS. In none of the patients or control subjects did unenhanced TCCS investigations depict any color-coded vascular signal of an intracranial vessel. After application of 9 mL of 400 mg/mL galactose-based microbubbles, CE-TCCS was performed. In subjects with MCA occlusion, CE-TCCS examinations were repeated within 24 h, 48 h and 5 days after stroke. In stroke patients (n = 20), CE-TCCS showed an occluded MCA main stem in 11 patients, and this vessel was clearly demonstrable on the unaffected side. On the affected side, the posterior cerebral artery (PCA) and anterior cerebral artery (ACA) could be visualized in 8 of 11 subjects; in 3 patients, at least 1 of these vessels was detectable. Angiographic studies confirmed the diagnosis of MCA trunk occlusion in all 11 individuals. In follow-up investigations, 3 stroke patients had angiographic and CE-TCCS examinations consistent with vessel reperfusion. Nine stroke patients had a patent MCA shown in angiographic and CE-TCCS examinations. In the control group, the MCA trunk could be visualized in all subjects by CE-TCCS. CE-TCCS is a sensitive and specific ultrasound method for the diagnosis of MCA trunk occlusion that overcomes the anatomical hindrance of inadequate acoustic bone window. This technique may help to identify patients suitable for thrombolytic therapies and monitor their response.

[High-resolution computed tomography of peripheral facial paralysis]. / Hochauflösende Computertomographie bei peripherer Fazialisparese.

High resolution computer tomographic examinations of the petrous bones were performed on 19 patients with confirmed peripheral facial nerve paralysis. High resolution CT provides accurate information regarding the extent, and usually regarding the type, of pathological process; this can be accurately localised with a view to possible surgical treatment. The examination also differentiates this from idiopathic paresis, which showed no radiological changes. Destruction of the petrous bone, without facial nerve symptoms, makes early suitable treatment mandatory.

[Computed tomographic control of the conventional x-ray findings in space-occupying lesions of the bony pelvis]. / Computertomographische Kontrolle konventionell röntgenologischer Befunde bei Raumforderungen des knöchernen Beckens.

The CT and conventional radiological findings in 30 patients with space-occupying lesions of the pelvic bones were compared. 73% of the tumours diagnosed by CT were shown by conventional means and in 71% their extent was correctly estimated. Lesions at the ilio-sacral junction are not demonstrated as well by conventional methods as those near the hip joint. The lesions most frequently missed by conventional radiography lie in the dorsal part of the ilium and in the lateral mass of the sacrum.

[Improved radiographic diagnosis of expanding lesions of the thoracic wall by computer tomography (author's transl)]. / Erweiterung der Röntgendiagnostik raumfordernder Prozesse der Thoraxwand durch die Computertomographie.

The findings of conventional radiography were compared with the results of computer tomography in 91 patients with histologically confirmed lesions of the thoracic wall. In 22 (24%) CT gave no additional information. In 67 (74%), CT supplied additional information or narrowed the differential diagnosis. Particularly important on computer tomography was the enhancement brought about by intravenous contrast medium in malignant tumours of the thorax or thoracic wall. CT should be used in preference to conventional tomography in the investigation of lesions of the thoracic wall.

[The radiation loading of the crystalline lens and thyroid during high-resolution computed tomography of the teeth]. / Untersuchung zur Strahlenbelastung von Augenlinse und Schilddrüse bei der hochauflösenden Computertomographie der Zähne.

The radiation dose to the ocular lens and thyroid gland during high resolution CT of the jaw was measured in a head phantom and in 9 patients. The dose for the lens and thyroid gland resulting from 10 cuts was 0.7 and 0.9 mGy, respectively. By shielding the thyroid gland against scatter a reduction of 20% is possible. Radiation exposure is considerably higher than during conventional dental x-ray examinations. Compared with CT examinations of the head and neck region, radiation exposure of both organs is about the same.

[CT findings in ileo-caval thrombosis (author's transl)]. / CT-Befunde bei iliokavalen Thrombosen.

Thrombosis of a large vein can be demonstrated by CT. The thrombosed vein has a hypodense lumen, with a somewhat increased diameter which does not opacify after intravenous contrast injection, but which shows a narrow hyperdense margin. Collateral vessels in the pelvic or paravertebral plexus and dilated veins in the abdominal skin are indirect evidence of ileo-caval thrombosis. CT can also demonstrate the cranial extent of a caval thrombosis. Venous thrombosis demonstrated by CT is an important additional finding in the pre-operative examination of the abdomen.

[High-resolution computed tomography in the diagnosis of bone-destroying processes of the external ear]. / Die hochauflösende Computertomographie in der Abklärung knochendestruierender Prozesse des äusseren Ohres.

Eleven patients with known malignant tumours of the outer ear and three patients with otitis externa maligna were examined by high resolution CT. CT provided accurate information concerning soft tissue infiltration into the parotid or subtemporal tissues, and of the bony destruction in the mastoid, meatus and tympanic cavity. Absolute differentiation between a malignant tumour and otitis cisterna maligna is not possible, not even by high resolution CT.

[Value of high-resolution CT in diagnosing acquired cholesteatoma of the middle ear]. / Stellenwert der hochauflösenden CT in der Diagnostik der erworbenen Mittelohrcholesteatome.

In thirty patients with cholesteatomas of the middle ear, high resolution CT of the petrous bone was performed in conjunction with the clinical examination. The extent of the soft tissue process can be demonstrated by CT, but differentiation of the cholesteatoma from the accompanying inflammatory changes is not possible. Typical complications such as destruction of the auditory ossicles, the bony labyrinth, the facial canal, the lateral wall of the attic and the superior and inferior walls of the tympanic cavity are clearly demonstrated. Changes in the mastoids are better demonstrated than by conventional radiography. Using the high contrast and special resolution of modern high resolution CT, this has become the method of choice in the investigation of cholesteatomas of the middle ear.