John Heliopoulos

Democritus University of Thrace, Xánthi, Anatoliki Makedonia kai Thraki, Greece

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Publications (5)8.04 Total impact

  • Article: Mild cognitive impairment: effect of education on the verbal and nonverbal tasks performance decline.
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    ABSTRACT: We sought to longitudinally evaluate the potential association of educational level with performance on verbal and nonverbal tasks in individuals with mild cognitive impairment (MCI). We evaluated patients with MCI, age >50 years, no medication intake, absent vascular risk factors, and no lesions on brain magnetic resonance imaging (MRI). Each patient underwent a clinical assessment packet and a series of neuropsychological tests of the language and constructional praxis subtests of Cambridge Cognitive Examination (CAMGOG) and the Boston naming test (BNT), at baseline, 6 months, and 12 months. Educational levels were defined taking into account the total years of education, the school level, and diplomas. MCI patients with low education level showed a stepwise reduction in scores of naming objects (NO; P = 0.009), definition (DF; P = 0.012), language (LT; P = 0.021), constructional praxis (CD; P = 0.022), confrontation naming skills (BXB; P = 0.033), phonemic help (BFB; P = 0.041), and BNT (P = 0.002). Analysis of covariance, controlling for baseline scores, showed that education was associated with NO score (P = 0.002), DF score (P = 0.005), LT (P = 0.008), CD score (P = 0.008), BXB score (44.36 ± 1.84, P = 0.0001), BFB (P = 0.022), and BNT (P = 0.004). Our findings indicate that education appeared to affect verbal and nonverbal task performance in MCI patients. Despite the fact that higher educated patients are more acquainted with the tasks, slower deterioration in consecutive follow-up examinations could be explained by the cognitive reserve theory. The potential association of this protective effect with delayed onset of symptoms deserves further investigation.
    Brain and behavior. 09/2012; 2(5):620-7.
  • Article: Detection of carotid artery plaque ulceration using 3-dimensional ultrasound.
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    ABSTRACT: Three-dimensional (3D) ultrasound imaging is a new technique that maximizes the information and image quality of traditional 2-dimensional (2D) B-mode scanning. The aim of this study was to evaluate the ability of the 3D ultrasound technique to characterize ulcerated atherosclerotic carotid plaque. Using conventional 2D ultrasound, we examined 284 carotid arteries from 142 consecutive patients (101 men and 41 women; average age, 64 years). Eighty-two carotid arteries were symptomatic with atherosclerotic plaque causing 50-99% stenosis. In 62 arteries, the atherosclerotic plaques were visualized completely and were further processed to construct 3D images. Two independent observers rated plaque morphology according to a standardized protocol. The 3D ultrasound showed carotid plaque ulceration more frequently than the 2D method (16.1% and 14.5% of plaques, for observers 1 and 2, respectively, versus 6.5% and 9.7% of plaques, for observers 1 and 2, respectively, P=.125 and P=.063, for observers 1 and 2, respectively). The interobserver reproducibility was very good for both methods (κ=.973, SE=.027, P<.001 for 3D, and κ=.885, SE=.055, P<.001 for 2D), although the 3D method was slightly superior to 2D. 3D ultrasound reliably characterized the surface morphology of atherosclerotic carotid plaques. A trend of superiority of 3D ultrasound over 2D was found in detecting ulcers of carotid artery plaque.
    Journal of neuroimaging: official journal of the American Society of Neuroimaging 11/2009; 21(2):126-31. · 1.72 Impact Factor
  • Article: Flapping of the dissected intima in a case of traumatic carotid artery dissection in a jackhammer worker.
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    ABSTRACT: We present the sonographic finding of flapping of the dissected intima inside the carotid artery in a 48-year-old man who suffered an acute stroke after vigorous use of a jackhammer. The dissected intima was seen to flap inside the lumen regularly and in synchrony with the vessel's pulse. There was no distal segmental stenosis. The extracranial blood flow velocities were within normal limits and transcranial Doppler examination did not reveal any velocity alteration.
    Journal of Clinical Ultrasound 03/2009; 37(4):221-2. · 0.81 Impact Factor
  • Article: Transcranial Doppler sonography: abnormal waveform pattern of intracranial arteries in acute aortic arch dissection.
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    ABSTRACT: We describe an interesting pattern of transcranial Doppler (TCD) intracranial blood flow waveforms in a patient with an acute aortic arch type A dissection. A 49-year-old patient presented with a low blood pressure after a syncopal episode, severe chest pain, and mild left hemiparesis. Contrast-enhanced computed tomography revealed the aortic arch dissection and the formation of the false lumen. TCD revealed an abnormal waveform pattern recorded in middle cerebral, internal carotid, and anterior cerebral arteries bilaterally with a pre-systolic sharp wave that gave the appearance of duplicated systolic phase. Our finding adds another interesting pattern of hemodynamic changes in cerebral circulation in patients with acute aortic arch dissections.
    Journal of neuroimaging: official journal of the American Society of Neuroimaging 11/2008; 19(4):375-7. · 1.72 Impact Factor
  • Article: A three-dimensional ultrasonographic quantitative analysis of non-ulcerated carotid plaque morphology in symptomatic and asymptomatic carotid stenosis.
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    ABSTRACT: Studies evaluating the association between carotid plaque composition and occurrence of ischemic cerebrovascular disease reveal inconsistent results. This study correlates the carotid echomorphology with the degree of stenosis in symptomatic and asymptomatic patients. We included consecutive patients with hemispheric stroke or asymptomatic carotid artery stenosis assessed with 2D ultrasound. The echomorphology was assessed with mean gray value (MGV) of the three-dimensional (3D) volume. We used the free-hand approach for 3D image and volume acquisition. Analyses of the stored carotid plaque volumes were carried out offline using the Virtual Organ Computer-aided Analysis (VOCAL) program. We studied 110 symptomatic and 104 asymptomatic atherosclerotic carotid plaques. MGV was lower in symptomatic carotid plaques causing <70% stenosis compared to plaques causing > or =70% stenosis (25.95+/-7.40 vs. 32.16+/-11.35, p=0.002). There was no difference in MGV between plaques producing <60% and those with > or =60% in asymptomatic patients (32.08+/-8.36 vs. 31.46+/-9.25, p=0.724). There were significant differences in MGV between symptomatic and asymptomatic plaques causing <60 or <70% stenosis; MGV was lower in symptomatic patients. Lower plaque echogenicity is observed in symptomatic than in asymptomatic patients with moderate degree of carotid stenosis, indicating that it is a significant factor for the production of cerebral ischemia. Our method could be useful in assessing the risk of cerebral ischemia and the response of carotid artery atherosclerosis to medical therapies.
    Atherosclerosis 06/2008; 198(1):129-35. · 3.79 Impact Factor