Mild cognitive impairment: effect of education on the verbal and nonverbal tasks performance decline.

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.

Detection of carotid artery plaque ulceration using 3-dimensional ultrasound.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Flapping of the dissected intima in a case of traumatic carotid artery dissection in a jackhammer worker.

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.

Transcranial Doppler sonography: abnormal waveform pattern of intracranial arteries in acute aortic arch dissection.

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.

A three-dimensional ultrasonographic quantitative analysis of non-ulcerated carotid plaque morphology in symptomatic and asymptomatic carotid stenosis.

BACKGROUND AND PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Evaluation of the stability of blood flow over time in the dominant hemisphere: a functional transcranial Doppler study.

Functional transcranial Doppler (fTCD) has been used for the identification of cerebral hemispheric dominance in various cognitive tasks. In our study, we have used fTCD with the aim to compare blood flow patterns in the hemispheres not only during the task activation periods but also in the post-stimulus phase. Normal volunteers, 25 right and 25 left-handed, were included. Mean flow velocities (FVs) in the bilateral middle cerebral arteries were recorded during the performance of six cognitive tasks and during the intervals between tasks. The lateralization index (LI) was calculated separately for each test (LI1-6), on the basis of the percent change of blood FV from baseline. To estimate flow fluctuations, a novel index, the LI-variability, was also calculated using a formula constituted by the minimum and maximum mean values recorded at specific time intervals during the entire procedure. Laterization indices, LI-3 and LI-4, corresponding to word generation and reading aloud tasks, produced the highest degree of activation. A perfect agreement (Cohen's kappa=1.000, P<0.001) was observed among LI-3, LI-4, and LI-V. The repetition of recordings gave excellent test-retest reliability in 10 randomly selected participants. Our results suggest that the hemisphere that is characterized as dominant by fTCD maintains a more stable flow pattern during the performance of successive cognitive tasks. Although it could not be considered as a clinically useful tool as yet, this observation introduces a novel parameter such as the stability of blood flow over time, which could potentially provide insight in the study of cerebral functions.

Analysis of the CD2 and spliceosomal Sm B/B' polyproline-arginine motifs defined by a monoclonal antibody using a phage-displayed random peptide library.

The cytoplasmic region of the CD2 receptor of lymphocytes contains proline-rich motifs, which are involved in T cell activation and interleukin-2 production. An intracellular CD2 binding protein, CD2BP2, interacts with two tandem PPPPGHR segments of the CD2 tail. CD2BP2 contains a GYF (glycine-tyrosine-phenylalanine) domain that confers binding to these proline-rich sequences. Monoclonal antibody 3E10 that was previously raised against a peptide containing the CD2 PPPPGHR segment reacts with the native CD2 molecule and spliceosomal Sm B/B' proteins. To identify the exact epitope on the CD2 peptide recognized by 3E10, a phage-displayed combinatorial peptide library was used. Analysis of the selected clones revealed that the mAb 3E10 binds preferentially to the motif PxxPPGxR. Experiments using amino acid substitutions with synthetic peptides confirmed the reactivity of mAb 3E10 with this motif. In addition, we show that several similarities exist between this motif and the CD2BP2-GFY recognition motif PPGxR/K. Binding of antibody 3E10 indicates some degree of degeneracy, which is consistent with its ability to recognize structurally related polyproline-arginine motifs found in intracellular proteins including Sm B/B' proteins and other RNA binding proteins. Thus, mAb 3E10 can be used to specifically identify a sub-class of proline-rich motifs, and as such can be used to study the potential role of these proline-rich sequences in mediating protein-protein interactions.