Felix Schlachetzki

Universität Regensburg, Ratisbon, Bavaria, Germany

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Publications (104)321.8 Total impact

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    ABSTRACT: Spontaneous intracranial hypotension (SIH) is most commonly caused by cerebrospinal fluid (CSF) leakage. Therefore, we hypothesised that patients with orthostatic headache (OH) would show decreased optic nerve sheath diameter (ONSD) during changes from supine to upright position. Transorbital B-mode ultrasound was performed employing a high-frequency transducer for ONSD measurements in the supine and upright positions. Absolute values and changes of ONSD from supine to upright were assessed. Ultrasound was performed in 39 SIH patients, 18 with OH and 21 without OH, and in 39 age-matched control subjects. The control group comprised 20 patients admitted for back surgery without headache or any orthostatic symptoms, and 19 healthy controls. In supine position, mean ONSD (±SD) was similar in patients with (5.38±0.91 mm) or without OH (5.48±0.89 mm; p=0.921). However, in upright position, mean ONSD was different between patients with (4.84±0.99 mm) and without OH (5.53±0.99 mm; p=0.044). Furthermore, the change in ONSD from supine to upright position was significantly greater in SIH patients with OH (-0.53±0.34 mm) than in SIH patients without OH (0.05±0.41 mm; p≤0.001) or in control subjects (0.01±0.38 mm; p≤0.001; area under the curve: 0.874 in receiver operating characteristics analysis). Symptomatic patients with SIH showed a significant decrease of ONSD, as assessed by ultrasound, when changing from the supine to the upright position. Ultrasound assessment of the ONSD in two positions may be a novel, non-invasive tool for the diagnosis and follow-up of SIH and for elucidating the pathophysiology of SIH. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
    Journal of neurology, neurosurgery, and psychiatry 08/2015; DOI:10.1136/jnnp-2015-310853 · 6.81 Impact Factor
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    ABSTRACT: Purpose. To characterize indications, treatment, and length of stay in a stand-alone neurological intensive care unit with focus on comparison between ventilated and nonventilated patient. Methods. We performed a single-center retrospective cohort study of all treated patients in our neurological intensive care unit between October 2006 and December 2008. Results. Overall, 512 patients were treated in the surveyed period, of which 493 could be included in the analysis. Of these, 40.8% had invasive mechanical ventilation and 59.2% had not. Indications in both groups were predominantly cerebrovascular diseases. Length of stay was 16.5 days in mean for ventilated and 3.6 days for nonventilated patient. Conclusion. Most patients, ventilated or not, suffer from vascular diseases with further impairment of other organ systems or systemic complications. Data reflects close relationship and overlap of treatment on nICU with a standardized stroke unit treatment and suggests, regarding increasing therapeutic options, the high impact of acute high-level treatment to reduce consequential complications.
    Neurology Research International 07/2015; 2015:696038. DOI:10.1155/2015/696038
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    ABSTRACT: The effects of anesthetics on the injured brain continue to be the subject of controversial discussion. Since isoflurane has recently been shown to induce apoptosis of cerebral endothelial cells, this study compared different anesthetic compounds regarding their potential to induce cerebro-vascular apoptosis. The in vitro model of the blood-brain barrier used in this study consisted of astrocyte-conditioned human umbilical vein endothelial cells (AC-HUVEC) has been used. After 24 h of deep hypoxia and reoxygenation or control treatment, AC-HUVEC were exposed to 0, 0.5, 1.0, or 2.0 times the minimum alveolar concentration of isoflurane or sevoflurane, or 0, 75, 150, or 300 nM of midazolam for 2 h. After 24 h, AC-HUVEC were harvested, and the degree of apoptosis was assessed by means of Western blots for the Bax and Bcl-2 ratio and, for controls and the highest concentration groups, terminal deoxynucleotidyl-mediated dUTP-biotin nick end labeling (TUNEL). Without hypoxic pretreatment, 2.0 MAC of isoflurane slightly increased TUNEL intensity compared to control and sevoflurane, but without any significant changes in the Bax and Bcl-2 ratio. After hypoxic pretreatment, exposure to isoflurane led to a multifold increase in the Bax and Bcl-2 ratio in a dose dependent manner, which was also significantly higher than the ratio observed in the 2 MAC sevoflurane group. TUNEL intensity in the post-hypoxic 2 MAC isoflurane group was increased by a factor of 11 vs. control and by 40 vs. sevoflurane. Sevoflurane and midazolam did not significantly alter these markers of apoptosis, when compared to the control group. Isoflurane administered after hypoxia elevates markers of apoptosis in endothelial cells transdifferentiated to the cerebro-vascular endothelium. Endothelial apoptosis may be a previously underestimated mechanism of anesthetic neurotoxicity. Administration of high concentrations of isoflurane in experimental settings may have negative effects on the blood-brain barrier.
    PLoS ONE 06/2015; 10(6):e0130408. DOI:10.1371/journal.pone.0130408 · 3.23 Impact Factor
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    ABSTRACT: Cerebral thromboembolism builds the Achilles heel for patients on left ventricular support (LVAD). Thrombolytic therapy is usually contraindicated considering the increased risk of intracranial hemorrhage in LVAD patients under therapeutic oral anticoagulation with concomitant platelet inhibition. We report on an alternative approach to this dilemma. On day 1091 of LVAD support (INCOR(R) Berlin Heart) a 69-year-old male patient was admitted to a rural hospital unconscious with a left sided hemiplegia. Cerebral computed tomography (cCT) with CT-angiography revealed a thrombembolic distal basilar artery occlusion. The patient was immediately transported to our medical center, where an interventional thrombectomy restored full patency of the vessel. The patient recovered without neurological sequelae within days. This case highlights the fact that patients on LVAD support with a neurological event should be immediately transferred to a neurovascular center for appropriate treatment including a neurointervention.
    ASAIO Journal 04/2015; 61(3):e17-e18. DOI:10.1097/MAT.0000000000000223 · 1.52 Impact Factor
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    ABSTRACT: Recently, diffusion-weighted magnetic resonance imaging (DW-MRI) revealed silent cerebral events (SCEs) as an acute complication of pulmonary vein isolation (PVI). We investigated whether SCEs following PVI are associated with neuropsychological deficits observed during patients' follow-up examinations. After PVI, 52 patients were eligible for follow-up. PVI was performed using a variety of ablation technologies (duty-cycled phased radiofrequency (RF) multipolar ablation with the Pulmonary Vein Ablation Catheter® (PVAC) in 24 patients, cooled-tip RF ablation in 23 patients, and cryoballoon ablation in five patients). Fluid-attenuated inversion recovery (FLAIR)- and DW-MRI studies were performed 1 day before PVI and 1 day and 1 month afterward to detect pre-existing cerebral lesions or post-ablation SCEs. At the same times, eight neuropsychological tests were administered. We evaluated changes in patients' neuropsychological capabilities and compared changes in patients with SCEs to those without SCEs. FLAIR-MRI revealed pre-existing cerebral lesions in 42 patients (81 %), and DW-MRI demonstrated new SCEs in 25 patients (48 %) (17 treated with phased RF (PVAC) (71 %), six treated with irrigated RF (26 %), and two treated with cryoablation (40 %)). Neuropsychological test results showed no significant impairment (in median z scores) 1 day and 1 month after the ablation procedure. There was no difference in neuropsychological capabilities between patients with SCEs and those without SCEs except in one subtest (part of the verbal working memory test). The incidence of pre-existing cerebral lesions and post-ablation SCEs was high. The frequency of SCEs depends on the ablation technology used. Neither PVI nor post-ablation SCEs have any effect on neuropsychological capabilities.
    Journal of Interventional Cardiac Electrophysiology 04/2015; 43(3). DOI:10.1007/s10840-015-0004-6 · 1.58 Impact Factor
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    ABSTRACT: Thoracic endovascular aortic repair (TEVAR) is associated with a reasonable risk of spinal ischemia. As cerebrospinal fluid pressure (CSFP) is correlated with the rate of paraplegia, a non-invasive method to estimate CSFP could help to estimate the patient's individual risk and guide the therapeutic approach. The quantification of the optic nerve sheath diameter (ONSD) using ocular sonography (OS) could be a suitable technique and was examined in the present study. 28 patients with TEVAR were included. Five consecutive measurements of the ONSD were performed in each patient. The first before the intervention ("baseline"), the next immediately postinterventional at the intensive care unit (post1), measurements 3, 4 (post2, post3) on day 1 and 2 after the intervention and number 5 (post4) before discharge. Statistical analysis was done using the Wilcoxon-test. A p-value < 0.05 was considered statistically significant. A significant increase between baseline and post1-measurements (right eye: p = 0.006; left eye: p = 0.02) could be detected. A significant decrease was detected between post1 and post3 (right eye: p = 0.02; left eye: p < 0.01). A group of 5 patients had an additional increase of ONSD from post1 to post2, one of these patients developed a permanent paraplegia. Patients with spinal catheters had significantly lower ONSDs at nearly all time points. The present study is the first to prospectively examine and prove the possibility to monitor CSFP changes in patients with TEVAR associated transient spinal edema using OS. Systematic factors as artificial ventilation and body positioning did not have a significant effect. Copyright © 2015 by the American Society of Neuroimaging.
    Journal of neuroimaging: official journal of the American Society of Neuroimaging 03/2015; 126(8). DOI:10.1111/jon.12234 · 1.73 Impact Factor
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    ABSTRACT: Intracranial hemorrhages are associated with high rates of disability and mortality. Telemedicine in general provides clinical healthcare at a distance by using videotelephony and teleradiology and is used particularly in acute stroke care medicine (TeleStroke). TeleStroke considerably improves quality of stroke care (for instance, by increasing thrombolysis) and may be valuable for the management of intracranial hemorrhages in rural hospitals and hospitals lacking neurosurgical departments, given that surgical/interventional therapy is only recommended for a subgroup of patients. The aim of this study was to analyze the frequency, anatomical locations of intracranial hemorrhage, risk factors, and the proportion of patients transferred to specialized hospitals. We evaluated teleconsultations conducted between 2008 and 2010 in a large cohort of patients consecutively enrolled in the Telemedical Project for Integrated Stroke Care (TEMPiS) network. In cases in which intracranial hemorrhage was detected, all images were re-examined and analyzed with a focus on frequency, location, risk factors, and further management. Overall, 6187 patients presented with stroke-like symptoms. Intracranial hemorrhages were identified in 631 patients (10.2%). Of these, intracerebral hemorrhages were found in 423 cases (67.0%), including 174 (41.1%) in atypical locations and 227 (53.7%) in typical sites among other locations. After 14 days of hospitalization in community facilities, the mortality rate in patients with intracranial hemorrhages was 15.1% (95/631). Two hundred and twenty-three patients (35.3%) were transferred to neurological/neurosurgical hospitals for diagnostic workup or additional treatment. Community hospitals are confronted with patients with intracranial hemorrhage, whose management requires specific neurosurgical and hematological expertise with respect to hemorrhage subtype and clinical presentation. TeleStroke networks help select patients who need advanced neurological and/or neurosurgical care. The relatively low proportion of interhospital transfers shown in this study reflects a differentiated decision process on the basis of both guidelines and standard operating procedures.
    Neuroreport 01/2015; 26(2):81-7. DOI:10.1097/WNR.0000000000000304 · 1.52 Impact Factor
  • Journal of neuroimaging: official journal of the American Society of Neuroimaging 09/2014; 25(3). DOI:10.1111/jon.12161 · 1.73 Impact Factor
  • Lukas Kremmler · Karin Pfister · Sabine Bogdahn · Saida Zoubaa · Felix Schlachetzki
    Circulation 07/2014; 130(4):348-9. DOI:10.1161/CIRCULATIONAHA.114.009703 · 14.43 Impact Factor
  • M Ertl · F Barinka · E Torka · M Altmann · K Pfister · H Helbig · U Bogdahn · M A Gamulescu · F Schlachetzki
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    ABSTRACT: Ocular color-coded duplex sonography (OCCS), when performed within the safety limits of diagnostic ultrasonography, is an easy noninvasive technique with high potential for diagnosis and therapy in diseases with raised intracranial pressure and vascular diseases affecting the eye. Despite the capabilities of modern ultrasound systems and its scientific validation, OCCS has not gained widespread use in neurological practice. In this review, the authors describe the technique and main parameter settings of OCCS systems to reduce potential risks as thermal or cavitational effects for sensitive orbital structures. Applications of OCCS are the determination of intracranial pressure in emergency medicine, and follow-up evaluations of idiopathic intracranial hypertension and ventricular shunting by measuring the optic nerve sheath diameter. A diameter of 5.7 - 6.0 mm corresponds well with symptomatically increased intracranial pressure (> 20 cmH2O). OCCS also helps to discriminate between different etiologies of central retinal artery occlusion - by visualization of a "spot sign" and Doppler flow analysis of the central retinal artery - and aids the differential diagnosis of papilledema. At the end perspectives are illustrated that combine established ultrasound methods such as transcranial color-coded sonography with OCCS.
    Ultraschall in der Medizin 03/2014; 35(5). DOI:10.1055/s-0034-1366113 · 4.92 Impact Factor
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    ABSTRACT: BACKGROUND AND PURPOSECentral retinal artery occlusion (CRAO) is most often indirectly diagnosed by lack of retinal perfusion. Direct embolus characterization may help to understand the natural course and low response to treatment. In a previous study we identified a hyperechoic signal within the optic nerve and in the central retinal artery (“spot sign”).METHODS In this study we performed a follow-up investigation in 7 patients with CRAO and positive spot sign indicating the embolic cause of the occlusion after a median interval of 17 months (range 11-38 months) using a battery of tests (ocular color-coded sonography, optic coherence tomography [OCT], fundoscopy, amongst others).RESULTSThe spot sign persisted in all patients, none had high-grade internal carotid artery stenosis, stroke or transient ischemic attacks. Four patients were completely blind, 3 patients were able to recognize hand movements. OCT demonstrated retinal atrophy, and fundoscopy revealed only minimal arterial perfusion.CONCLUSIONS The hyperechoic spot sign may be an important predictive prognostic marker for persistent loss of vision. Its persistence may indicate calcified or cholesterol emboli and may explain the low therapeutic success rate to thrombolysis. Further studies on their origin and significance in atherosclerotic disease are warranted.
    Journal of neuroimaging: official journal of the American Society of Neuroimaging 03/2014; 25(2). DOI:10.1111/jon.12112 · 1.73 Impact Factor
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    ABSTRACT: Transcranial color-coded sonography (TCCS) has proved to be a fast and reliable tool for the detection of middle cerebral artery (MCA) occlusions in a hospital setting. In this feasibility study on prehospital sonography, our aim was to investigate the accuracy of TCCS for neurovascular emergency diagnostics when performed in a prehospital setting using mobile ultrasound equipment as part of a neurological examination. Following a '911 stroke code' call, stroke neurologists experienced in TCCS rendezvoused with the paramedic team. In patients with suspected stroke, TCCS examination including ultrasound contrast agents was performed. Results were compared with neurovascular imaging (CTA, MRA) and the final discharge diagnosis from standard patient-centered stroke care. We enrolled '232 stroke code' patients with follow-up data available in 102 patients with complete TCCS examination. A diagnosis of ischemic stroke was made in 73 cases; 29 patients were identified as 'stroke mimics'. MCA occlusion was diagnosed in ten patients, while internal carotid artery (ICA) occlusion/high-grade stenosis leading to reversal of anterior cerebral artery flow was diagnosed in four patients. The initial working diagnosis 'any stroke' showed a sensitivity of 94% and a specificity of 48%. 'Major MCA or ICA stroke' diagnosed by mobile ultrasound showed an overall sensitivity of 78% and specificity of 98%. The study demonstrates the feasibility and high diagnostic accuracy of emergency transcranial ultrasound assessment combined with neurological examinations for major ischemic stroke. Future combination with telemedical support, point-of-care analysis of blood serum markers, and probability algorithms of prehospital stroke diagnosis including ultrasound may help to speed up stroke treatment.
    Critical ultrasound journal 02/2014; 6(1):3. DOI:10.1186/2036-7902-6-3
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    ABSTRACT: Patient: Female, 78 Final Diagnosis: Cerebral hyperperfusion syndrome Symptoms: - Medication: - Clinical Procedure: Endovascular embolectomy Specialty: Neurology. Unknown ethiology. Cerebral hyperperfusion syndrome (cHS) is a well known but rare complication after carotid endarterectomy, carotid angioplasty with stenting, and stenting of intracranial arterial stenosis. The clinical presentation may vary from acute onset of focal oedema (stroke-like presentation) and intracerbral hemorrhage to delayed (>24h hours after the procedure) presentation with seizures, focal motor weakness, or late intracerebral hemorrhage. The incidence of cHS after carotid endarterectomy ranges from 0-3% and defined as an increase of the ipsilateral cerebral blood flow up to 40% over baseline in ultrasound. We present a case of a 78-year-old woman with an acute ischemic stroke due to left side middle cerebral artery territory with right sided hemiparesis and aphasia (NIHSS 16). After systemic thrombolysis embolectomy using a retractable stent (Solitaire(®) device) was performed and resulted in complete and successful recanalization of MCA including its branches about 210 minutes after symptom onset but, partial dislocation of thrombotic material into the anterior cerebral artery (ACA). Cerebral hyperperfusion syndrome should be considered in patients with clinical deterioration after successful recanalisation and the early diagnosis and treatment may be important for neurological outcome after endovascular embolectomy.
    American Journal of Case Reports 11/2013; 14:513-7. DOI:10.12659/AJCR.889672
  • Ulrich Bogdahn · Felix Schlachetzki · Gerhard Schuierer
    Stroke 08/2013; 44(9). DOI:10.1161/STROKEAHA.113.002340 · 5.72 Impact Factor
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    ABSTRACT: Introduction: Moyamoya disease (MMD) is an extremely rare neurovascular disorder in Caucasian children. To the best of our knowledge, the aggressive variant including hemorrhagic malignant stroke and consecutive global ischemia has not been reported for this population before. Case report: We present the case of an 11-year-old girl with sudden neurological deterioration due to intracerebral hemorrhage with early irruption into the ventricular system. MMD with extensive neovascularization was diagnosed by means of computed tomography and magnetic resonance imaging. Despite immediate ventricular drainage, intracranial pressure increased above the mean arterial pressure resulting in malignant bi-hemispheric ischemia. The girl died within 53 h after admission to hospital. Discussion: Intracerebral hemorrhage in young patients is often attributed to vascular malformation. This case shows that MMD may constitute a potential diagnosis in the case of sudden neurological deterioration and loss of consciousness, even in previously healthy children.
    Child s Nervous System 04/2013; 29(8). DOI:10.1007/s00381-013-2089-5 · 1.11 Impact Factor
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    ABSTRACT: Stroke is the second common cause of death and the primary cause of early invalidity worldwide. Different from other diseases is the time sensitivity related to stroke. In case of an ischemic event occluding a brain artery, 2000000 neurons die every minute. Stroke diagnosis and treatment should be initiated at the earliest time point possible, preferably at the site or during patient transport. Portable ultrasound has been used for prehospital diagnosis for applications other than stroke, and its acceptance as a valuable diagnostic tool "in the field" is growing. The intrahospital use of transcranial ultrasound for stroke diagnosis has been described extensively in the literature. Beyond its diagnostic use, first clinical trials as well as numerous preclinical work demonstrate that ultrasound can be used to accelerate clot lysis (sonothrombolysis) in presence as well as in absence of tissue plasminogen activator. Hence, the use of transcranial ultrasound for diagnosis and possibly treatment of stroke bares the potential to add to current stroke care paradigms significantly. The purpose of this concept article is to describe the opportunities presented by recent advances in transcranial ultrasound to diagnose and potentially treat large vessel embolic stroke in the prehospital environment.
    The American journal of emergency medicine 02/2013; 31(4). DOI:10.1016/j.ajem.2012.12.030 · 1.27 Impact Factor
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    ABSTRACT: The 'new penumbra' concept imbues the transition between injury and repair at the neurovascular unit with profound implications for selecting the appropriate type and timing of neuroprotective interventions. In this conceptual study, we investigated the protective effects of pigment epithelium-derived factor (PEDF) and compared them with the properties of epidermal growth factor (EGF) in a rat model of ischemia-reperfusion injury. We initiated a delayed intervention 3 hours after reperfusion using equimolar amounts of PEDF and EGF. These agents were then administered intravenously for 4 hours following reperfusion after 1 hour of focal ischemia. Magnetic resonance imaging indices were characterized, and imaging was performed at multiple time points post reperfusion. PEDF and EGF reduced lesion volumes at all time points as observed on T(2)-weighted images (T(2)-LVs). In addition PEDF selectively attenuated lesion volume expansion at 48 hours after reperfusion and persistently modulated blood-brain barrier (BBB) permeability at all time points. Intervention with peptides is suspected to cause edema formation at distant regions. The observed T(2)-LV reduction and BBB modulation by these trophic factors is probably mediated through a number of diverse mechanisms. A thorough evaluation of neurotrophins is still necessary to determine their time-dependent contributions against injury and their modulatory effects on repair after stroke.Journal of Cerebral Blood Flow & Metabolism advance online publication, 9 January 2013; doi:10.1038/jcbfm.2012.201.
    Journal of cerebral blood flow and metabolism: official journal of the International Society of Cerebral Blood Flow and Metabolism 01/2013; 33(4). DOI:10.1038/jcbfm.2012.201 · 5.41 Impact Factor
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    ABSTRACT: BACKGROUND: This article gives an up-to-date overview of neurosonographic emergency and intensive care diagnostics. METHODS: Selective literature research from 1984 with critical appraisal and including national and international guidelines. RESULTS: Fast and valid diagnostics in acute stroke is the main field of application of neurosonography. Specific monitoring methods bear great advantages for intensive care patients, especially "as-often-as-wanted" repetitive imaging under real-time conditions. A number of new developments make neurosonography an interesting area of research. CONCLUSIONS: Neurosonography has played a key role in neurological emergency and intensive care medicine for many years. It remains important to continuously support dissemination of the method.
    Medizinische Klinik - Intensivmedizin und Notfallmedizin 10/2012; · 0.56 Impact Factor
  • M Ertl · M Altmann · E Torka · H Helbig · U Bogdahn · A Gamulescu · F Schlachetzki
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    ABSTRACT: Purpose: Sudden retinal blindness is a common complication of temporal arteritis (TA). Another common cause is embolic occlusion of the central retinal artery (CRA). The aim of this prospective study was to examine the diagnostic value of hyperechoic material in the CRA for the exclusion of vasculitis as a cause. The authors used orbital color-coded sonography (OCCS) for the detection of hyperechoic material. Materials and methods: 24 patients with sudden vision loss were included in the study after the exclusion of other causes (e. g. vitreous bleeding, retinal detachment). Parallel to routine diagnostic workup, OCCS was performed in all patients. Results: 7 patients with a diagnosis of TA presented with different degrees of hypoperfusion in the CRA without hyperechoic material (referred to as "spot sign") detected by OCCS. Diagnostic workup in the remaining 17 patients revealed other causes of sudden vision loss, such as central retinal artery occlusion (CRAO) (12), anterior ischemic optic neuropathy (AION) (2), upstream vascular stenosis or occlusion (2) and delayed reperfusion of the CRA (1). The hyperechoic "spot sign" was visible in 10 of 12 patients (83 %) with embolic CRAO. The detection of embolic CRAO using the "spot sign" had a sensitivity of 83 % and a specificity of 100 %. The missing "spot sign" in patients with TA was a highly specific finding (p-value 0.01). Conclusion: The detection of the "spot sign" specifically minimizes the probability of TA as a reason for sudden blindness.
    Ultraschall in der Medizin 09/2012; 33(7). DOI:10.1055/s-0032-1312925 · 4.92 Impact Factor

Publication Stats

1k Citations
321.80 Total Impact Points


  • 2001–2015
    • Universität Regensburg
      • Department of Neurology
      Ratisbon, Bavaria, Germany
  • 2008–2013
    • University Hospital Regensburg
      • Klinik und Poliklinik für Neurologie
      Ratisbon, Bavaria, Germany
    • University of California, San Diego
      San Diego, California, United States
    • Leibniz Universität Hannover
      Hanover, Lower Saxony, Germany
  • 2003
    • University of California, Los Angeles
      • Department of Medicine
      Los Angeles, CA, United States
  • 2002
    • Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center
      • Department of Medicine
      Torrance, California, United States
  • 2000
    • Justus-Liebig-Universität Gießen
      Gieben, Hesse, Germany