Creatine kinase-MB elevation after stroke is not cardiac in origin: comparison with troponin T levelsHakan Ay
Department of Neurology, Hacettepe University Hospital, Ankara, Turkey
Stroke 33:286-9. 2002
..Troponin T has superior sensitivity and specificity to CK-MB in revealing minor myocardial injury. Therefore, we studied troponin T levels after stroke to determine whether troponin T increases in parallel to CK-MB...
- Hyperhomocysteinemia is associated with the presence of left atrial thrombus in stroke patients with nonvalvular atrial fibrillation
Hakan Ay
Department of Neurology, Hacettepe University Hospital, Ankara, Turkey
Stroke 34:909-12. 2003
..In the present study, we hypothesized that high homocysteine might be associated with thrombus formation in another stasis-related condition, atrial fibrillation...
- 'Footprints' of transient ischemic attacks: a diffusion-weighted MRI study
Hakan Ay
Stroke Service of the Neurology, Massachusetts General Hospital, and Harvard Medical School, Boston, Mass, USA
Cerebrovasc Dis 14:177-86. 2002
..We aimed to determine the proportion and clinical characteristics of patients with TIA who harbor infarction(s) on DWI...
- Unusually prolonged progressing stroke: an expanding anterior cerebral artery infarction
Hakan Ay
Department of Neurology, Hacettepe University Hospital, Ankara, Turkey
Cerebrovasc Dis 13:64-6. 2002
..Occasional patients like ours indicate that stroke is a dynamic disorder with an extremely variable clinical course and state of tissue injury...
- Conversion of ischemic brain tissue into infarction increases with age
Hakan Ay
The AA Martinos Center, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
Stroke 36:2632-6. 2005
..We hypothesize that age is a marker for tissue susceptibility to ischemia and thus plays a role in determining tissue outcome in human stroke...
Severity of leukoaraiosis and susceptibility to infarct growth in acute strokeHakan Ay
A A Martinos Center for Biomedical Imaging and Stroke Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Room 2301, Charlestown, MA 02129, USA
Stroke 39:1409-13. 2008
..We hypothesized that the volume of LA correlated with the proportion of initially ischemic but eventually infarcted tissue in acute human stroke...
- Long-term exposure to repetitive hyperbaric oxygen results in cumulative oxidative stress in rat lung tissue
Kemal Simsek
Gulhane Military Medical Academy, Department of Undersea and Hyperbaric Medicine, Ankara, Turkey
Inhal Toxicol 23:166-72. 2011
..Nevertheless, these studies were usually performed with single-session HBO exposure but its clinical use commonly depends on long-term exposure periods...
- Oxidative stress levels in rats following exposure to oxygen at 3 atm for 0-120 min
Sukru Oter
Department of Physiology, Gulhane Military Medical Academy, Ankara, Turkey
Aviat Space Environ Med 78:1108-13. 2007
..We previously defined the pressure-related oxidative effects of HBO in several tissues of rats. This study was performed to elucidate the relationship of HBO exposure time to its oxidative effects...
National Institutes of Health Stroke Scale score is poorly predictive of proximal occlusion in acute cerebral ischemiaMatthew B Maas
Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Mass, USA
Stroke 40:2988-93. 2009
..Use of National Institutes of Health Stroke Scale (NIHSS) score to predict a proximal arterial occlusion (PO) is suggested by several case series as a viable method of selecting cases appropriate for multimodal imaging...
- Clinical- and imaging-based prediction of stroke risk after transient ischemic attack: the CIP model
Hakan Ay
AA Martinos Center for Biomedical Imaging and Stroke Service, Departments of Neurology and Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Room 2301, Charlestown MA 02129, USA
Stroke 40:181-6. 2009
..We sought to combine imaging and clinical features to improve predictions for 7-day stroke risk after transient ischemic attack...
- Evaluation of the oxidative effect of long-term repetitive hyperbaric oxygen exposures on different brain regions of rats
Kemal Simsek
Department of Undersea and Hyperbaric Medicine, Gulhane Military Medical Academy, 06010 Etlik, Ankara, Turkey
ScientificWorldJournal 2012:849183. 2012
..These comparable results provide evidence for the safety of HBO treatments and/or successful adaptive mechanisms at least in the brain tissue of rats, even when administered for longer periods...
- Admission international normalized ratio and acute infarct volume in ischemic stroke
Hakan Ay
Department of Neurology, Stroke Service, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
Ann Neurol 64:499-506. 2008
..We explored the relation between admission international normalized ratio (INR) and acute infarct volume in patients with ischemic stroke...
- Interexaminer difference in infarct volume measurements on MRI: a source of variance in stroke research
Hakan Ay
Stroke Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Room 2301, Charlestown MA 02129, USA
Stroke 39:1171-6. 2008
..We sought to quantify the variance imposed by measurement error in DWI and PWI lesion volume measurements in ischemic stroke...
- Wake-up stroke: clinical and neuroimaging characteristics
Gisele S Silva
Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA giselesampaio hotmail com
Cerebrovasc Dis 29:336-42. 2010
..In these patients, in whom the time from symptom onset is uncertain, brain imaging is a potential strategy to characterize the ischemia duration and the presence of salvageable brain tissue...
- Prediction of early stroke risk in transient symptoms with infarction: relevance to the new tissue-based definition
E Murat Arsava
A A Martinos Center for Biomedical Imaging, Department of Radiology Massachusetts General Hospital, Harvard Medical School, Charlestown MA 02129, USA
Stroke 42:2186-90. 2011
..We sought to assess the utility of a Web-based recurrence risk estimator (RRE; http://www.nmr.mgh.harvard.edu/RRE/) originally developed for use in patients with ischemic stroke for predicting 7-day risk of stroke in patients with TSI...
- The prognosis for aphasia in stroke
Matthew B Maas
Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
J Stroke Cerebrovasc Dis 21:350-7. 2012
..The purpose of this study is to assess the prognosis for recovery of language function in subjects presenting with aphasia caused by ischemic stroke within 12 hours of symptom onset...
- Age-dependent susceptibility to infarct growth in women
Figen Gokcay
AA Martinos Center for Biomedical Imaging and Stroke Service, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Room 2301, Charlestown, MA 02129, USA
Stroke 42:947-51. 2011
..We sought to identify whether the proportion of initially ischemic to eventually infarcted tissue was different between men and women with ischemic stroke...
- Collateral vessels on CT angiography predict outcome in acute ischemic stroke
Matthew B Maas
Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Mass, USA
Stroke 40:3001-5. 2009
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- A computerized algorithm for etiologic classification of ischemic stroke: the Causative Classification of Stroke System
Hakan Ay
AA Martinos Center for Biomedical Imaging and Stroke Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Room 2301, Charlestown, MA 02129, USA
Stroke 38:2979-84. 2007
..In this article, we present an automated version of the SSS-TOAST, the Causative Classification System (CCS), to facilitate its utility in multicenter settings...
- Time-dependent course of hyperbaric oxygen-induced oxidative effects in rat lung and erythrocytes
Hakan Ay
Department of Undersea and Hyperbaric Medicine, Gulhane Military Medical Academy, Ankara, Turkey
Clin Exp Pharmacol Physiol 34:787-91. 2007
..Further studies should focus on the molecular mechanisms that can be activated during this time interval...
- Middle cerebral artery infarcts encompassing the insula are more prone to growth
Hakan Ay
Department of Neurology, A A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
Stroke 39:373-8. 2008
....
- Lower hemoglobin correlates with larger stroke volumes in acute ischemic stroke
W Taylor Kimberly
Department of Neurology, Massachusetts General Hospital, Boston, Mass, USA
Cerebrovasc Dis Extra 1:44-53. 2011
..Hemoglobin tetramers are the major oxygen-carrying molecules within the blood. We hypothesized that a lower hemoglobin level and its reduced oxygen-carrying capacity would associate with larger infarction in acute ischemic stroke patients...
- Similarities and differences of hyperbaric oxygen and medical ozone applications
Mehmet Ozler
Department of Physiology, Gulhane Military Medical Academy, Ankara, Turkey
Free Radic Res 45:1267-78. 2011
..We will try to emphasize the similarities and differences of HBO and medical ozone applications in this article...
- The real estate factor: quantifying the impact of infarct location on stroke severity
Nina M Menezes
Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and the Harvard Massachusetts Institute of Technology Division of Health Sciences and Technology, Boston, MA, USA
Stroke 38:194-7. 2007
..In the current study, we sought to quantify the impact of location on neurological deficit severity and to delineate this impact from that of volume...
- Transient ischemic attack with infarction: a unique syndrome?
Hakan Ay
Department of A A Martinos Center for Biomedical Imaging and Stroke Service, Department of Radiology, Boston, MA 02129, USA
Ann Neurol 57:679-86. 2005
..3% in those with ischemic stroke. TIA with infarction appears to have unique features separate from TIA without infarction and ischemic stroke. We propose identifying TSI as a separate clinical syndrome with distinct prognostic features...
- Concurrent acute brain infarcts in patients with monocular visual loss
Johanna Helenius
A A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
Ann Neurol 72:286-93. 2012
..We sought to determine the frequency of acute brain infarcts on diffusion-weighted imaging (DWI) in patients with monocular visual loss of presumed ischemic origin (MVL)...
- Protective role of 27bp repeat polymorphism in intron 4 of eNOS gene in lacunar infarction
Muge Yemisci
Department of Neurology, Hacettepe University, Ankara, Turkey
Free Radic Res 43:272-9. 2009
..Intron 4aa genotype of eNOS gene seems to be protective for isolated LI and the effect was potentiated by the absence of 786C polymorphism in any allele of the promoter region...
- Mild induced hypertension improves blood flow and oxygen metabolism in transient focal cerebral ischemia
Hwa Kyoung Shin
Stroke and Neurovascular Regulation Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
Stroke 39:1548-55. 2008
..We, therefore, tested whether pharmacologically induced hypertension improves cerebral blood flow and metabolism and tissue outcome in acute stroke using optical imaging with high spatiotemporal resolution...
- CT and conventional and diffusion-weighted MR imaging in acute stroke: study in 691 patients at presentation to the emergency department
Mark E Mullins
Neuroradiology Division, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, GRB285, Boston, MA 02114, USA
Radiology 224:353-60. 2002
..After 12 hours, accuracy was equivalent. CONCLUSION: In the diagnosis of stroke in the early period (<12 hours after presentation), DW MR imaging is superior to conventional MR imaging and CT...
- An evidence-based causative classification system for acute ischemic stroke
Hakan Ay
A A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
Ann Neurol 58:688-97. 2005
..The SSS-TOAST is a dynamic algorithm that can accommodate modifications as new epidemiological data accumulate and diagnostic techniques advance...
- Ischemic-appearing electrocardiographic changes predict myocardial injury in patients with intracerebral hemorrhage
Kohei Hasegawa
Department of Emergency Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
Am J Emerg Med 30:545-52. 2012
..Our objective is to examine whether ischemic-appearing ECG changes predict subsequent myocardial injury in the context of ICH...
- Transient ischemic attack: definition, diagnosis, and risk stratification
A Gregory Sorensen
Department of Radiology, A A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, 13th Street, CNY149 2301, Boston, MA 02129, USA
Neuroimaging Clin N Am 21:303-13, x. 2011
..The use of neuroimaging in TIA is therefore critical not only for diagnosis but also for accurate risk stratification. In this article, recent advances in diagnostic imaging, categorizations, and risk stratification in TIA are discussed...
- Echocardiographic predictors of left atrial appendage spontaneous echocontrast in patients with stroke and atrial fibrillation
Necla Ozer
Department of Cardiology, Hacettepe University, Ankara, Turkey
J Am Soc Echocardiogr 18:1362-5. 2005
..The purpose of this study was to define the new transesophageal echocardiographic predictors of SEC for patients with stroke and atrial fibrillation...
- Diffusion tensor imaging shows structural remodeling of stroke mirror region: results from a pilot study
Cristina Granziera
Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
Eur Neurol 67:370-6. 2012
..In this pilot study, we sought to explore the presence of structural changes detectable by diffusion tensor imaging (DTI) in the contralesional hemispheres of patients who recovered well from ischemic stroke...
- Effect of using local arterial input functions on cerebral blood flow estimation
Cory Lorenz
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts, USA
J Magn Reson Imaging 24:57-65. 2006
..CONCLUSION: The local-AIF technique results in an increase in the calculated CBF values for tissues with D/D, consistent with a reduction in the errors associated with D/D...
- Middle ear barotrauma with hyperbaric oxygen therapy: incidence and the predictive value of the nine-step inflation/deflation test and otoscopy
Serdar Karahatay
Department of Otorhinolaryngology Head and Neck Surgery, Gulhane Military Medical Academy, Ankara, Turkey
Ear Nose Throat J 87:684-8. 2008
..We conclude that patients with even minor positive pathologic findings on otoscopy immediately following HBOT are at increased risk of middle ear barotrauma if HBOT is to be continued without prophylaxis...
- Effectiveness of hyperbaric oxygen on sudden sensorineural hearing loss: prospective clinical research
Kadir Dundar
Undersea and Hyperbaric Medicine Department, Gulhane Military Medical Academy, Ankara, Turkey
J Otolaryngol 36:32-7. 2007
..05) but not in the medical treatment group (p>.05). In the HBO and medical treatment group, average hearing gain on each audiometric frequency was better than in the medical treatment group (p<.05)...
- Advances in the diagnosis of etiologic subtypes of ischemic stroke
Hakan Ay
Stroke Service and A A Martinos Center for Biomedical Imaging, Departments of Neurology and Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Room 2301, Charlestown, MA, 02129, USA
Curr Neurol Neurosci Rep 10:14-20. 2010
..This article highlights important theoretical aspects of etiologic stroke classification and reviews major etiologic classification systems that have benefited from recent advances in etiologic stroke evaluation...
- Statin potentiates human platelet eNOS activity without enhancing eNOS mRNA and protein levels
Muge Yemisci
Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
Cerebrovasc Dis 26:190-8. 2008
..Hence, we investigated changes in eNOS activity, mRNA and protein levels after statin treatment in human platelets, which are readily accessible unlike arteries...
- Primary angiitis of the central nervous system and silent cortical hemorrhages
Hakan Ay
Department of Neurology, Hacettepe University Hospitals, Sihhiye 06100, Ankara, Turkey
AJNR Am J Neuroradiol 23:1561-3. 2002
..The identification of petechial hemorrhages by gradient-echo MR imaging promises to be a valuable surrogate marker supporting the diagnosis of primary angiitis of the CNS...
- Buerger's disease with multisystem involvement. A case report and a review of the literature
Meral Calguneri
Department of Rheumatology, Hacettepe University School of Medicine, Ankara, Turkey
Angiology 55:325-8. 2004
..Therefore, Buerger's disease, although rare, does have a chronic aggressive nature in some patients...
- Carotid artery stenting and endarterectomy have different effects on heart rate variability
Mehmet Demirci
Hacettepe University Hospitals, Department of Neurology, Ankara, Turkey
J Neurol Sci 241:45-51. 2006
..Altered cardiac autonomic modulation may play a role in the occurrence of cardiac disturbances following carotid interventions...
- Urethral stripping caused by stent removal and its successful treatment with hyperbaric oxygen therapy: a case report
Lutfu Tahmaz
Department of Urology, Gulhane Military Medical Academy, Ankara, Turkey
Kaohsiung J Med Sci 25:334-7. 2009
..Here we present a case of urethral stripping caused by endoscopic stent removal, and its conservative treatment with HBO therapy...
- Protective effects of exogenously administered or endogenously produced melatonin on hyperbaric oxygen-induced oxidative stress in the rat brain
Kadir Dundar
Department of Undersea and Hyperbaric Medicine, Gulhane Military Medical Academy, Ankara, Turkey
Clin Exp Pharmacol Physiol 32:926-30. 2005
..5. In conclusion, HBO caused oxidative stress and melatonin exhibited protective effects. Both endogenously produced and exogenously administered melatonin were found to be effective...
- Antiplatelet resistance in stroke
Mehmet Akif Topcuoglu
Hacettepe University Hospitals, Department of Neurology, Ankara, Turkey
Expert Rev Neurother 11:251-63. 2011
....
- Effect of hyperbaric oxygen on flow-mediated vasodilation: an ultrasound study
Mutlu Saglam
Department of Radiology, Gulhane School of Medicine, Ankara, Turkey
J Ultrasound Med 27:209-14. 2008
..The purpose of this study was to investigate the effect of hyperbaric oxygen (HBO) treatment on flow-mediated vasodilation (FMD) by ultrasound examination...
- Diffusion-weighted MRI for the "small stuff": the details of acute cerebral ischaemia
Achim Gass
NMR Research Neurology, Department of Neurology, Universitaetsklinikum Mannheim, Germany
Lancet Neurol 3:39-45. 2004
..DWI is becoming an important technique for optimum management of patients...
- How much should one rely on computed tomography in patients with TIA in the era of diffusion-weighted magnetic resonance imaging?
Hakan Ay
Stroke 35:e72; author reply e72. 2004
- Hyperbaric oxygen therapy decreases QT dispersion in diabetic patients
Ejder Kardesoglu
Department of Cardiology, Gulhane Military Medical Academy, Haydarpasa Teaching Hospital, Istanbul, Turkey
Tohoku J Exp Med 215:113-7. 2008
..We have concluded that HBO therapy may reduce the risk of malignant ventricular arrhythmia and sudden cardiac death in diabetic patients when applied repetitively...
- Automated perfusion-weighted MRI using localized arterial input functions
Cory Lorenz
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Division of Health Sciences and Technology, Harvard/MIT, Charlestown, Massachusetts 08129, USA
J Magn Reson Imaging 24:1133-9. 2006
..Similarly, the local MTT lesion volumes had the least mean squared error (MSE). CONCLUSION: Automated CBF calculation using local AIFs is feasible and appears to produce more useful CBF maps...
