Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 86
Filter
Add more filters

Country/Region as subject
Publication year range
1.
J Neuroradiol ; 42(6): 332-7, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26410100

ABSTRACT

INTRODUCTION: Cell-dense tumors may restrict diffusivity which can be measured by diffusion-weighted MRI (DWI), and which is quantified by the apparent diffusion coefficient (ADC). Little is known about diffusivity in meningiomas. These tumors frequently show hemorrhage and calcification which can be demonstrated using susceptibility weighted MRI (SWI). Both DWI and SWI represent T2-derived MRI sequences. Here we investigated ADC variability in meningiomas and analyzed whether susceptibility changes (SWIpos) alter diffusivity. METHODS: We grouped newly diagnosed meningiomas according to the presence (SWIpos) or absence (SWIneg) of susceptibility changes. ADC values were calculated using region-of-interest analysis, and ADC values of SWIpos and SWIneg meningiomas were compared. In addition ADC histograms were created. RESULTS: We retrospectively studied 36 patients (13 WHO grade I, 8 WHO grade II, 15 suspected meningiomas). Thirteen meningiomas (36%) exhibited SWIpos. Global ADC values were higher in SWIpos (1.00 ± 0.15 × 10-3mm(2)/s) compared to SWIneg (0.82 ± 0.09 × 10-3mm(2)/s) tumors (P<0.0001). Meningiomas showing both SWIpos and SWIneg areas caused two separated histogram peaks, whereas homogeneously appearing meningiomas with either SWIposor SWIneg areas showed one peak only. ADC values did not correlate with age or gender, and showed substantial overlap between WHO grade I and II. CONCLUSION: Susceptibility changes (SWIpos) in meningiomas influence measures of diffusivity by increasing ADC values on average by 38%. This shift has to be considered when conclusions on tumor behavior are drawn from DWI. Further studies should address whether ADC changes and histogram patterns can be used to monitor treatment of meningiomas.


Subject(s)
Brain/diagnostic imaging , Diffusion Magnetic Resonance Imaging/methods , Meningeal Neoplasms/diagnostic imaging , Meningioma/diagnostic imaging , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Retrospective Studies
2.
Sci Robot ; 9(87): eadh0298, 2024 Feb 14.
Article in English | MEDLINE | ID: mdl-38354258

ABSTRACT

Treating vascular diseases in the brain requires access to the affected region inside the body. This is usually accomplished through a minimally invasive technique that involves the use of long, thin devices, such as wires and tubes, that are manually maneuvered by a clinician within the bloodstream. By pushing, pulling, and twisting, these devices are navigated through the tortuous pathways of the blood vessels. The outcome of the procedure heavily relies on the clinician's skill and the device's ability to navigate to the affected target region in the bloodstream, which is often inhibited by tortuous blood vessels. Sharp turns require high flexibility, but this flexibility inhibits translation of proximal insertion to distal tip advancement. We present a highly dexterous, magnetically steered continuum robot that overcomes pushability limitations through rotation. A helical protrusion on the device's surface engages with the vessel wall and translates rotation to forward motion at every point of contact. An articulating magnetic tip allows for active steerability, enabling navigation from the aortic arch to millimeter-sized arteries of the brain. The effectiveness of the magnetic continuum robot has been demonstrated through successful navigation in models of the human vasculature and in blood vessels of a live pig.


Subject(s)
Robotics , Humans , Animals , Swine , Motion , Magnetic Phenomena
3.
Clin Transl Radiat Oncol ; 47: 100798, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38938931

ABSTRACT

Purpose: Preoperative radiosurgery (SRS) of brain metastases (BM) aims to achieve cavity local control with a reduction in leptomeningeal relapse (LMD) and without additional radionecrosis compared to postoperative SRS. We present the final results of a prospective feasibility trial of linac-based stereotactic radiosurgery (SRS) prior to neurosurgical resection of a brain metastasis (PREOP-1). Methods: Eligibility criteria included a BM up to 4 cm in diameter for elective resection. The primary endpoint was the feasibility of delivering linac-based preoperative SRS in all patients prior to anticipated gross tumour resection. Secondary endpoints included rates of LMD, local control and overall survival. Exploratory endpoints were the level of expression of immunological and proliferative markers. Results: Thirteen patients of median age 65 years (range 41-77) were recruited. Twelve patients (92 %) received preoperative radiosurgery and metastasectomy and one patient went directly to surgery and received postoperative SRS, thus the primary endpoint was not met. The median time between referral and preoperative SRS was 6.5 working days (1-10) and from SRS to neurosurgery was 1 day (0-5). The median prescribed dose was 16 Gy (14-19) to a median planning target volume of 12.7 cm3 (5.9-26.1). Five patients completed 12-month follow-up after preoperative SRS without local recurrence or leptomeningeal disease. The patient who received postoperative FSRT developed LMD after six months. There was one transient toxicity (grade 2 alopecia) and nine patients have died from extracranial causes. Patients reported significant improvement in motor weakness at 6 months (P = 0.04). No pattern in changes of marker expression was observed. Conclusion: In patients with large brain metastasis without raised intracranial pressure, linac-based preoperative SRS was feasible in 12/13 patients and safe in 12/12 patients without any surgical delay or intracranial complications.

4.
Eur Stroke J ; 8(2): 575-580, 2023 06.
Article in English | MEDLINE | ID: mdl-37231695

ABSTRACT

PURPOSE: There is little data on the safety and efficacy of endovascular treatment (EVT) in comparison with intravenous thrombolysis (IVT) in acute ischemic stroke due to isolated posterior cerebral artery occlusion (IPCAO). We aimed to investigate the functional and safety outcomes of stroke patients with acute IPCAO treated with EVT (with or without prior bridging IVT) compared to IVT alone. METHODS: We did a multicenter retrospective analysis of data from the Swiss Stroke Registry. The primary endpoint was overall functional outcome at 3 months in patients undergoing EVT alone or as part of bridging, compared with IVT alone (shift analysis). Safety endpoints were mortality and symptomatic intracranial hemorrhage. EVT and IVT patients were matched 1:1 using propensity scores. Differences in outcomes were examined using ordinal and logistic regression models. FINDINGS: Out of 17,968 patients, 268 met the inclusion criteria and 136 were matched by propensity scores. The overall functional outcome at 3 months was comparable between the two groups (EVT vs IVT as reference category: OR = 1.42 for higher mRS, 95% CI = 0.78-2.57, p = 0.254). The proportion of patients independent at 3 months was 63.2% in EVT and 72.1% in IVT (OR = 0.67, 95% CI = 0.32-1.37, p = 0.272). Symptomatic intracranial hemorrhages were overall rare and present only in the IVT group (IVT = 5.9% vs EVT = 0%). Mortality at 3 months was also similar between the two groups (IVT = 0% vs EVT = 1.5%). CONCLUSION: In this multicenter nested analysis, EVT and IVT in patients with acute ischemic stroke due to IPCAO were associated with similar overall good functional outcome and safety. Randomized studies are warranted.


Subject(s)
Brain Ischemia , Endovascular Procedures , Ischemic Stroke , Stroke , Humans , Thrombolytic Therapy/adverse effects , Retrospective Studies , Ischemic Stroke/etiology , Posterior Cerebral Artery , Switzerland/epidemiology , Treatment Outcome , Stroke/therapy , Intracranial Hemorrhages/etiology , Registries , Endovascular Procedures/adverse effects
5.
J Physiol ; 587(Pt 9): 1977-87, 2009 May 01.
Article in English | MEDLINE | ID: mdl-19289547

ABSTRACT

Larger body parts are somatotopically represented in the primary motor cortex (M1), while smaller body parts, such as the fingers, have partially overlapping representations. The principles that govern the overlapping organization of M1 remain unclear. We used transcranial magnetic stimulation (TMS) to examine the cortical encoding of thumb movements in M1 of healthy humans. We performed M1 mapping of the probability of inducing a thumb movement in a particular direction and used low intensity TMS to disturb a voluntary thumb movement in the same direction during a reaction time task. With both techniques we found spatially segregated representations of the direction of TMS-induced thumb movements, thumb flexion and extension being best separated. Furthermore, the cortical regions corresponding to activation of a thumb muscle differ, depending on whether the muscle functions as agonist or as antagonist for flexion or extension. In addition, we found in the reaction time experiment that the direction of a movement is processed in M1 before the muscles participating in it are activated. It thus appears that one of the organizing principles for the human corticospinal motor system is based on a spatially segregated representation of movement directions and that the representation of individual somatic structures, such as the hand muscles, overlap.


Subject(s)
Evoked Potentials/physiology , Motor Cortex/physiology , Movement/physiology , Muscle, Skeletal/innervation , Muscle, Skeletal/physiology , Nerve Net/physiology , Thumb/physiology , Adult , Female , Humans , Male , Middle Aged , Thumb/innervation
6.
Case Rep Pathol ; 2019: 7159395, 2019.
Article in English | MEDLINE | ID: mdl-31355036

ABSTRACT

A 71-year-old woman was admitted with angina pectoris. During hospitalization she developed a myocardial infarction (NSTEMI). Laboratory results revealed a mild elevated troponin and an elevated calcium level (3.35 mmol/l). Subsequently, there was a decreased phosphate (0.36 mmol/l [normal 0.81-1.62 mmol/l]) as well as 16-fold elevated serum level of parathyroid hormone (PTH, 1156 ng/l [normal 10-73 ng/l]), indicating a primary hyperparathyroidism. Sonographically a thyroidal node was detected, not clearly demarcated (TIRADS 5). FNA showed a monomorphic, partial follicular cell population with an immunohistochemical positivity for PTH. Magnetic resonance imaging (MRI) showed a 5 cm large tumor at the right caudal pole of the thyroid with compression of the dorsolateral trachea without infiltration. Surgical removal with en bloc resection of the right hemithyroid with parathyroidectomy was performed. Postoperatively the PTH level dropped to 12.1 ng/l. Pathological examination revealed a 5 cm tumor with infiltration of the thyroid and a perineural invasion. The diagnosis of a presymptomatic parathyroid carcinoma could be established. The affirmative histopathological diagnosis of a parathyroid carcinoma can be challenging and is limited to tumors with evidence of invasive growth in adjacent structures such as the thyroid and/or soft tissue, perineural spaces, angioinvasion of capsular and/or extracapsular vessels, and/or documented metastases.

7.
J Neuroimaging ; 29(5): 645-649, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31112344

ABSTRACT

BACKGROUND AND PURPOSE: Susceptibility-weighted magnetic resonance imaging (SWI) yields information regarding tumor biology (e.g., hemorrhage) of growing gliomas. SWI changes can also be observed as a consequence of treatment, for example radiation therapy. The aim of our study was to investigate how susceptibility changes occur during the time course after completion of standard treatment in newly diagnosed glioblastoma (GBM). METHODS: Eighteen GBM patients were retrospectively analyzed. After completion of therapy, imaging was performed every 3 months. MRI was analyzed at the following time points: after the third and sixth cycle of adjuvant temozolomide chemotherapy, thereafter in 3 month intervals and at recurrence. The number of SWI positive tumor pixels was quantified and compared with progression as defined by the RANO criteria on T2- and contrast-enhanced T1-weighted MRI sequences (T1-CE). RESULTS: The MRI interval between completion of the sixth chemotherapy cycle and last MRI before progression was 390 ± 292 days. Between the last MRI before progression and at progression a significant increase in SWI positive tumor pixels was observed (P = .012), whereas tumor size remained unchanged (RANO T2: P = .385; RANO T1-CE: P = .165). The number of SWI positive pixels remained unchanged between last MRI before progression until progression (P = .149), whereas RANO T2 and T1-CE showed tumor progression (interval 128 ± 69 days). CONCLUSIONS: SWI positive pixel count increases significantly prior to changes in tumor size (RANO). Our findings may be explained by microbleeds compatible with stimulation of angiogenesis and possibly serve as an early biomarker of tumor progression.


Subject(s)
Antineoplastic Agents, Alkylating/therapeutic use , Brain Neoplasms/diagnostic imaging , Glioblastoma/diagnostic imaging , Temozolomide/therapeutic use , Adult , Aged , Brain Neoplasms/drug therapy , Brain Neoplasms/pathology , Disease Progression , Female , Glioblastoma/drug therapy , Glioblastoma/pathology , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Retrospective Studies , Treatment Outcome
8.
Clin Neuroradiol ; 29(1): 87-94, 2019 Mar.
Article in English | MEDLINE | ID: mdl-28913609

ABSTRACT

PURPOSE: Strabismus influences not only the individual with nonparallel eyes but also the observer. It has previously been demonstrated by fMRI that adults viewing images of strabismic adults have a negative reaction to the images as demonstrated by limbic activation, especially activation of the left amygdala. The aim of this study was to see if mothers would have a similar reaction to viewing strabismic children and whether or not that reaction would be different in mothers of strabismic children. METHODS: Healthy mothers of children with strabismus (n = 10, Group I) and without strabismus (n = 15, Group II) voluntarily underwent fMRI at 3T. Blood oxygen level dependent signal responses to viewing images of strabismic and non-strabismic children were analyzed. RESULTS: Group II, while viewing images of strabismic children, showed significantly increased activation of the limbic network (p < 0.05) and bilateral amygdala activation. Group I showed considerably less limbic activation, compared to the group II, and had no amygdala activation. Both groups revealed statically significant activation in the FEF (frontal eye field) when they were viewing images of strabismic children as compared to when they were viewing children with parallel eyes. The activated FEF area for Group II was much larger than for group I. CONCLUSION: Mothers of non-strabismic children showed similar negative emotional fMRI patterns as adults did while viewing strabismic adults. Strabismus is an interpersonal organic issue for the observer, which also impacts the youngest members of our society.


Subject(s)
Emotions/physiology , Limbic System/physiology , Magnetic Resonance Imaging/methods , Mothers/psychology , Strabismus/psychology , Adult , Amygdala/physiology , Child , Female , Humans , Middle Aged , Oxygen/blood , Photography
9.
Br J Anaesth ; 101(6): 855-9, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18948389

ABSTRACT

BACKGROUND: Retrobulbar anaesthesia allows eye surgery in awake patients. Severe complications of the blind techniques are reported. Ultrasound-guided needle introduction and direct visualization of the spread of local anaesthetic may improve quality and safety of retrobulbar anaesthesia. Therefore, we developed a new ultrasound-guided technique using human cadavers. METHODS: In total, 20 blocks on both sides in 10 embalmed human cadavers were performed. Using a small curved array transducer and a long-axis approach, a 22 G short bevel needle was introduced under ultrasound guidance lateral and caudal of the eyeball until the needle tip was seen 2 mm away from the optic nerve. At this point, 2 ml of contrast dye as a substitute for local anaesthetic was injected. Immediately after the injection, the spread of the contrast dye was documented by means of CT scans performed in each cadaver. RESULTS: The CT scans showed the distribution of the contrast dye in the muscle cone and behind the posterior sclera in all but one case. No contrast dye was found inside the optic nerve or inside the eyeball. In one case, there could be an additional trace of contrast dye behind the orbita. CONCLUSIONS: Our new ultrasound-guided technique has the potential to improve safety and efficacy of the procedure by direct visualization of the needle placement and the distribution of the injected fluid. Furthermore, the precise injection near the optic nerve could lead to a reduction of the amount of the local anaesthetic needed with fewer related complications.


Subject(s)
Eye/diagnostic imaging , Nerve Block/methods , Orbit/diagnostic imaging , Ultrasonography, Interventional/methods , Aged , Aged, 80 and over , Contrast Media/pharmacokinetics , Feasibility Studies , Female , Humans , Male , Middle Aged , Optic Nerve/diagnostic imaging , Tomography, X-Ray Computed
10.
Rofo ; 180(7): 604-13, 2008 Jul.
Article in German | MEDLINE | ID: mdl-18561064

ABSTRACT

This article provides an overview on the actual state of the interventional neuroradiological management of carotid cavernous fistulas depending on their anatomy and pathophysiology. The results are based on our experience gained during the treatment of patients with complex CCF during the last 15 years. Indications, procedures, and results of transarterial, transvenous and combined arteriovenous approaches for balloon occlusion, embolization, coiling and stenting of these lesions are discussed. Progress in this field is constant so that new technical advances are expected to improve the safety and to expand the indications for these procedures in the future.


Subject(s)
Carotid-Cavernous Sinus Fistula/diagnosis , Carotid-Cavernous Sinus Fistula/therapy , Catheterization/methods , Cerebral Angiography/methods , Embolization, Therapeutic/methods , Vascular Surgical Procedures/methods , Humans
11.
J Neuroradiol ; 35(5): 278-85, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18707758

ABSTRACT

OBJECTIVES: To determine the accuracy of automated vessel-segmentation software for vessel-diameter measurements based on three-dimensional contrast-enhanced magnetic resonance angiography (3D-MRA). METHOD: In 10 patients with high-grade carotid stenosis, automated measurements of both carotid arteries were obtained with 3D-MRA by two independent investigators and compared with manual measurements obtained by digital subtraction angiography (DSA) and 2D maximum-intensity projection (2D-MIP) based on MRA and duplex ultrasonography (US). In 42 patients undergoing carotid endarterectomy (CEA), intraoperative measurements (IOP) were compared with postoperative 3D-MRA and US. RESULTS: Mean interoperator variability was 8% for measurements by DSA and 11% by 2D-MIP, but there was no interoperator variability with the automated 3D-MRA analysis. Good correlations were found between DSA (standard of reference), manual 2D-MIP (rP=0.6) and automated 3D-MRA (rP=0.8). Excellent correlations were found between IOP, 3D-MRA (rP=0.93) and US (rP=0.83). CONCLUSION: Automated 3D-MRA-based vessel segmentation and quantification result in accurate measurements of extracerebral-vessel dimensions.


Subject(s)
Carotid Stenosis/diagnosis , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional , Magnetic Resonance Angiography/methods , Software Validation , Aged , Analysis of Variance , Angiography, Digital Subtraction , Carotid Stenosis/surgery , Contrast Media , Endarterectomy, Carotid , Female , Humans , Male , Prospective Studies , Retrospective Studies , Statistics, Nonparametric , Treatment Outcome , Ultrasonography, Doppler, Duplex
12.
J Neurol Neurosurg Psychiatry ; 78(3): 280-5, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17308290

ABSTRACT

BACKGROUND: The PROACT II trial showed that intra-arterial thrombolysis (IAT) is effective for treatment of acute ischaemic stroke attributable to M1 and M2 segment occlusions. Incidence of symptomatic intracranial haemorrhage (sICH) was 10%. OBJECTIVE: To evaluate the risk and predictors of sICH after IAT by using urokinase in a large number of patients presenting with the whole spectrum of cerebral vessel occlusions. METHODS: 294 patients with stroke treated with intra-arterial urokinase were retrospectively analysed. The risk of sICH as well as bleeding characteristics were assessed. Demographic and radiological data, time to treatment, urokinase dose, recanalisation rates, stroke aetiology and severity were analysed for predictors. RESULTS: sICH occurred in 14 of 294 (4.8%) patients. The median National Institute of Health Stroke Scale score of all patients was 15. All but one sICH were located in the infarcted brain tissue, and no sICH occurred in patients with peripheral vessel occlusions (M3 or M4 segments of the middle cerebral artery). Poor collaterals (p = 0.001), early signs of ischaemia on computed tomography (p = 0.003), higher urokinase dose (p = 0.019), lower recanalisation rate (p = 0.02) and higher diastolic blood pressure on admission (p = 0.04) were found to be correlated with sICH on univariate analysis. On multivariate analysis, poor collaterals (p = 0.004), urokinase dose (p = 0.021) and early signs on computed tomography (p = 0.026) remained predictors of sICH. CONCLUSIONS: With regard to the whole spectrum of cerebral vessel occlusions, an incidence of <5% sICH after IAT is distinctly low. This result underlines the important role of IAT in the treatment of acute stroke.


Subject(s)
Brain Ischemia/drug therapy , Fibrinolytic Agents/adverse effects , Intracranial Hemorrhages/chemically induced , Stroke/drug therapy , Thrombolytic Therapy/adverse effects , Urokinase-Type Plasminogen Activator/adverse effects , Acute Disease , Female , Fibrinolytic Agents/therapeutic use , Humans , Male , Middle Aged , Multivariate Analysis , Retrospective Studies , Risk Factors , Thrombolytic Therapy/methods , Urokinase-Type Plasminogen Activator/therapeutic use
13.
Eye (Lond) ; 31(9): 1365-1372, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28452990

ABSTRACT

PurposeTo investigate on the relationship between the optic nerve sheath diameter (ONSD) and the lumbar cerebrospinal fluid pressure (CSF-p) in Caucasian patients with normal tension glaucoma (NTG).Patients and methodsRetrospective analysis of medical records of patients with open-angle glaucoma in the period from 2005 to 2015 from the Ophthalmology Department, Cantonal Hospital Aarau, Switzerland was performed. A total of 38 patients (mean age 68.6±11.3 years, 21 females and 17 males) fulfilled the diagnostic criteria of NTG and underwent computed tomography (CT) of the orbit and lumbar puncture (LP). In total, 38 age- and gender-matched Caucasian subjects (mean age: 68.9±10.9 years) without known ON diseases served as controls for ONSD measurements. ONSDs were measured at a distance of 3 mm from the posterior globe and lumbar CSF-p was related to the measurements. Statistical analysis was performed by using the independent two-tailed t-test and the non-parametric Spearman's correlation test.ResultsThe mean ONSD in NTGs measured 6.4±0.9 mm and in controls 5.4±0.6 mm. The difference between NTGs and controls showed statistical significance (t-test: P<0.000). The mean CSF-p in NTG was 11.6±3.7 mm Hg. There was no statistical significant correlation between ONSD and CSF-p (Spearman's correlation coefficient ρ=0.06, P=0.72).ConclusionsThis study demonstrates enlarged ONSDs and normal lumbar CSF-p in 38 Caucasian NTG patients. As enlarged ONSDs generally are associated with increased intracranial CSF-p, these results can be explained by a disturbed communication of CSF-p between the intracranial and intraorbital subarachnoid spaces.


Subject(s)
Cerebrospinal Fluid Pressure/physiology , Low Tension Glaucoma/physiopathology , Myelin Sheath/pathology , Optic Nerve/pathology , Aged , Female , Humans , Intraocular Pressure/physiology , Male , Optic Nerve/diagnostic imaging , Retrospective Studies , Spinal Puncture , Subarachnoid Space , Tomography, X-Ray Computed , Tonometry, Ocular , Visual Field Tests , White People
14.
J Neurol ; 253(12): 1552-6, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17219032

ABSTRACT

BACKGROUND: In selected stroke centers intra-arterial thrombolysis (IAT) is used for the treatment of acute stroke patients presenting within 6 hours of symptom onset. However, data about eligibility of acute stroke patients for IAT in clinical practice are very scarce. METHODS: We collected prospectively data on indications advising for or against IAT of 230 consecutive stroke patients in a tertiary stroke center. RESULTS: 76 patients (33.0%) presented within 3 hours, 69 (30%) between 3 and 6 hours of symptom onset and 85 (37%) later than 6 hours. Arteriography was performed in 71 patients (31%) and IAT in 46 (20%). In 11 patients no or only peripheral branch occlusions were seen on arteriography and therefore IAT was not performed. In 9 patients the ICA was occluded and barred IAT and in five anatomical or technical difficulties made IAT impossible. 72 patients presenting within 6 hours did not undergo arteriography and thrombolysis, mostly because of mild (n=44) or rapidly improving neurological deficits (n=13). Other reasons to withhold IAT were CT and/or clinical findings suggesting lacunar stroke due to small vessel occlusion (n=7), limiting comorbidty (n=7) and baseline international normalized ratio>1.7 (n=1). CONCLUSIONS: A third of the patients underwent diagnostic arteriography and one fifth received IAT. The most important reasons to withhold thrombolysis were presentation beyond the 6 hours time window and mild or rapidly improving symptoms.


Subject(s)
Fibrinolytic Agents/therapeutic use , Stroke/drug therapy , Thrombolytic Therapy/methods , Treatment Outcome , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Injections, Intra-Arterial/methods , Magnetic Resonance Imaging , Male , Middle Aged , Prospective Studies , Retrospective Studies , Stroke/epidemiology , Time Factors
15.
AJNR Am J Neuroradiol ; 27(6): 1357-61, 2006.
Article in English | MEDLINE | ID: mdl-16775297

ABSTRACT

BACKGROUND: Recent studies have focused on mechanical thrombectomy as a means to reduce the time required for revascularization and increase the revascularization rate in acute stroke. To date no systematic evaluation has been made of the different mechanical devices in this novel and fast-developing field of endovascular interventions. To facilitate such evaluations, we developed a specific in vivo model for mechanical thrombectomy that allows visualization of dislocation or fragmentation of the thrombus during angiographic manipulation. METHODS: Angiography and embolization with a preformed thrombus was performed in 8 swine. The thrombus was generated by mixing 25 IU bovine thrombin and 10 mL autologous blood. For visualization during angiography, 1 g barium sulfate was added. RESULTS: The preformed thrombus exhibited mechanical stability, reproducibility, and high radiographic absorption, providing excellent visibility during angiography. The setting allowed selective embolization of targeted vessels without thrombus fragmentation. Despite the application of barium sulfate no local or systemic reaction occurred. Histologic evaluation revealed no intimal damage caused by the thrombus or contrast agent washout. CONCLUSION: The model presented here allows selective and reliable thromboembolization of vessels that reproduce the anatomic and hemodynamic situation in acute cerebrovascular stroke. It permits visualization of the thrombus during angiography and intervention, providing unique insight into the behavior of both thrombus and device, which is potentially useful in the development and evaluation of mechanical clot retrieval in acute cerebrovascular stroke.


Subject(s)
Disease Models, Animal , Intracranial Thrombosis/surgery , Stroke/surgery , Thrombectomy , Acute Disease , Angiography , Animals , Cerebral Angiography , Intracranial Thrombosis/diagnostic imaging , Stroke/diagnostic imaging , Swine
16.
AJNR Am J Neuroradiol ; 37(1): 114-9, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26294644

ABSTRACT

BACKGROUND AND PURPOSE: Intravenous thrombolysis and mechanical thrombectomy predominantly using stent retrievers have been shown to effectively restore cerebral blood flow and improve functional outcome in patients with acute ischemic stroke. We sought to determine the safety and feasibility of mechanical thrombectomy using the new ERIC retrieval device. MATERIALS AND METHODS: We identified 36 consecutive patients from our Stroke Center registry with acute ischemic stroke who were treated with the new ERIC retriever from September 2013 to December 2014. Patients with ischemic stroke meeting the following criteria were eligible: onset-to-treatment time of ≤4.5 hours or wake-up stroke (n = 10) with relevant CT perfusion mismatch, NIHSS score of ≥4, and proof of large-vessel occlusion in the anterior circulation on CT angiography. We assessed the baseline characteristics including age, sex, comorbidities, stroke severity, site of vessel occlusion, presence of tissue at risk, and treatment-related parameters such as onset-to-treatment time, recanalization grade, and outcome. RESULTS: The mean age was 70 ± 13 years, and the median NIHSS score on admission was 18 (interquartile range, 10-20). Seventeen of 36 patients were on platelet inhibitors or anticoagulants before endovascular treatment (47.2%); 20 patients received intravenous thrombolysis (55.5%). The ERIC was used as the sole retriever in 28 patients (77.8%) and as a rescue device in 8. Excellent recanalization was achieved in 30/36 patients (83.3%) with TICI 3 in 19/36 and 2b in 11/36, respectively. Median procedural time in these patients was 90 minutes (interquartile range, 58-133 minutes). No intraprocedural complications occurred. CONCLUSIONS: In this observational study, the new ERIC retrieval device was technically feasible, safe, and effective in acute ischemic stroke with large-vessel occlusion.


Subject(s)
Infarction, Anterior Cerebral Artery/surgery , Thrombectomy/instrumentation , Acute Disease , Aged , Aged, 80 and over , Cerebral Angiography , Combined Modality Therapy , Equipment Design , Equipment Safety , Feasibility Studies , Female , Humans , Infarction, Anterior Cerebral Artery/diagnostic imaging , Male , Middle Aged , Switzerland , Thrombolytic Therapy , Tomography, X-Ray Computed
17.
Ophthalmologe ; 102(4): 369-74, 2005 Apr.
Article in German | MEDLINE | ID: mdl-15599559

ABSTRACT

PURPOSE: To examine the clinical outcome of the balloon dilatation in stenosis of the canaliculus communis. METHOD: 18 nasolacrimal ducts with epiphora and proven obstruction of the canaliculus communis by dacryocystography (DCG) were treated with balloon dilatation in local anaesthesia. All patients were treated electively. RESULTS: In 16/18 cases the balloon dilatation was technically successful, in 2 patients the guide wire failed to pass the obstruction and the wire could not be placed in the nasal cavity. There were no complications. Over a mean follow-up of 6 months there were 2 reobstructions, one of these led to an occlusion of the canaliculus communis. 14/18 (77,8%) cases after DCP were treated successful, 11/18 cases were free of symptoms after DCP, in 4/18 cases the epiphora improved. CONCLUSIONS: Until recently in stenosis of the canaliculus communis the only therapeutic option was surgical procedure followed by silicone tube intubation. The results were often disappointing. In contrast to this balloon dacryocystoplasty is a minimally-invasive alternative in the therapy of stenosis of the canaliculus communis resulting in good clinical outcome during follow up.


Subject(s)
Catheterization/instrumentation , Lacrimal Apparatus Diseases/therapy , Lacrimal Duct Obstruction/therapy , Adult , Aged , Aged, 80 and over , Dacryocystorhinostomy , Female , Follow-Up Studies , Humans , Lacrimal Apparatus Diseases/diagnosis , Lacrimal Duct Obstruction/diagnosis , Male , Middle Aged , Recurrence , Treatment Outcome
18.
Ophthalmologe ; 102(4): 375-86, 2005 Apr.
Article in German | MEDLINE | ID: mdl-15599560

ABSTRACT

PURPOSE: To examine the clinical outcome of the ballon dilatation in stenosis and obstruction of the nasolacrimal duct. MATERIAL AND METHODS: 63 patients (69 nasolacrimal duct systems) with epiphora and proven obstruction of the nasolacrimal duct were treated with ballon dilatation, respectively Stentimplantation. In 55 cases there was a pre- or postsaccal stenosis, in 14 cases an occlusion of the nasolacrimal duct system. The diagnosis was established by dacryocystography. RESULTS: Technical success was obtained in 61 cases (n=50/55 stenosis; n=11/14 occlusions). Over a mean follow-up of 6 months patency of the nasolacrimal duct system was achieved in 83,6% (46/55) in stenosis. In occlusion the clinical outcome was 42,9% (6/14). CONCLUSION: Balloon dacryocystoplasty and Stentimplantation are minimal-invasive alternatives, performed in local anesthesia that recover the normal anatomy of the nasolacrimal duct system. They are a good alternative in the treatment of epiphora caused by nasolacrimal duct obstructions.


Subject(s)
Catheterization/instrumentation , Lacrimal Apparatus Diseases/therapy , Lacrimal Duct Obstruction/therapy , Stents , Adult , Aged , Aged, 80 and over , Female , Humans , Lacrimal Apparatus Diseases/diagnostic imaging , Lacrimal Duct Obstruction/diagnostic imaging , Male , Middle Aged , Outcome Assessment, Health Care , Radiography , Retreatment
19.
Acta Radiol Open ; 4(6): 2058460115589124, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26346318

ABSTRACT

BACKGROUND: Velocity-encoded magnetic resonance imaging (VENC-MRI) is a commonly used technique in cardiac examinations. This technique utilizes the phase shift properties of protons moving along a magnetic field gradient. VENC-MRI offers a unique way of measuring the severity of valve regurgitation by directly quantifying the regurgitation flow volume. PURPOSE: To compare flow analysis results of different software programs and to assess the effect of background correction in sample patient cases. MATERIAL AND METHODS: A phantom was built out of Polymethyl methacrylate (PMMA) which provides tubes of different diameters. These tubes can be connected to an external water circuit to generate a water flow inside the tubes. Expected absolute flow quantities inside the tubes were determined from preset tube- and flow-parameters. Different flow conditions were measured with a VENC-MRI sequence and the images evaluated using different software packages. In a second step six randomly selected patients showing different degrees of aortic insufficiency were evaluated in clinical terms. RESULTS: The contour propagation algorithms used in the software packages performed differently even on static phantom geometry. In terms of clinical evaluation the software packages performed similarly. Enabling background correction or leaving out manual correction of propagated contours changed results for severity of aortic insufficiency. CONCLUSION: Turning on background correction and manual correction of propagated contours in MRI flow volume measurements is strongly recommended.

20.
Neurology ; 55(1): 74-83, 2000 Jul 12.
Article in English | MEDLINE | ID: mdl-10891909

ABSTRACT

BACKGROUND: In previous studies, the authors found that patients with spontaneous confabulation differ from those with nonconfabulating amnesia by 1) temporal context confusion (TCC) in memory based on an inability to suppress intrusions of currently irrelevant memory traces into ongoing thinking; and 2) lesions involving the orbitofrontal cortex, basal forebrain, or amygdala and perirhinal cortex. OBJECTIVES: To study the long-term clinical course of spontaneous confabulations, determine whether TCC in memory also parallels the clinical course of spontaneous confabulations, and study the impact of lesion site on clinical course. METHODS: Eight patients with spontaneous confabulation were re-examined 18 months after onset. Tests of memory and executive functioning and measurement of TCC in memory were again applied. MRI according to a standard protocol was performed to determine areas of permanent damage. RESULTS: Seven patients eventually stopped confabulating. TCC, but not common memory or executive tests, precisely paralleled the course of spontaneous confabulations. Patients with isolated, less extensive, orbitofrontal lesions stopped confabulating first and had the best neuropsychological outcome. Patients with basal forebrain lesions continued to confabulate for several months and remained amnesic. One patient with extensive orbitofrontal damage and perirhinal cortex damage continues to confabulate after more than 3 years, continuing to confuse memory traces. CONCLUSIONS: Temporal context confusion in memory is not only the sole feature reliably separating patients with spontaneous confabulation from those with nonconfabulating amnesia in the acute stage, it is also the only feature that precisely parallels the clinical course of spontaneous confabulations. Most patients eventually stop confabulating but duration of confabulations depends on the lesion site.


Subject(s)
Amnesia/pathology , Confusion/pathology , Memory/physiology , Adult , Amnesia/physiopathology , Brain/diagnostic imaging , Brain/pathology , Brain/physiopathology , Brain Mapping , Confusion/physiopathology , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Time Perception/physiology , Tomography, X-Ray Computed
SELECTION OF CITATIONS
SEARCH DETAIL