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991.
Attentional blink in global versus local attentional modes 总被引:1,自引:0,他引:1
992.
Thompson PM; Moussai J; Zohoori S; Goldkorn A; Khan AA; Mega MS; Small GW; Cummings JL; Toga AW 《Cerebral cortex (New York, N.Y. : 1991)》1998,8(6):492-509
The onset of Alzheimer's disease (AD) is accompanied by a complex and
distributed pattern of neuroanatomic change, difficult to distinguish
clinically from dynamic alterations in normal aging. Extreme variations in
the sulcal patterns of the human cortex have made it difficult to identify
diffuse and focal variations in cortical structure in neurodegenerative
disease. We report the first comprehensive 3D statistical analysis of deep
sulcal structure in vivo, in both normal aging and dementia.
High-resolution 3D T1-weighted fast SPGR (spoiled GRASS) MRI volumes were
acquired from 10 patients diagnosed with AD (NINCDS-ARDRA criteria; age:
71.9 +/- 10.7 years) and 10 normal subjects matched for age (72.9 +/- 5.6
years), gender, educational level and handedness. Scans were digitally
transformed into Talairach stereotaxic space. To determine specific
patterns of cortical variation in dementia patients, 3D average and
probabilistic maps of primary deep sulci were developed for both normal and
AD groups. Major sulci (including supracallosal, cingulate, marginal,
parieto-occipital, anterior and posterior calcarine sulci, and Sylvian
fissures) were modeled as complex systems of 3D surfaces using a
multi-resolution parametric mesh approach. Variations and asymmetries in
their extents, curvature, area and surface complexity were evaluated.
Three- dimensional maps of anatomic variability, structural asymmetry and
local atrophy indicated severe regionally selective fiber loss in AD. A
midsagittal area loss of 24.5% at the corpus callosum's posterior midbody
(P < 0.025) matched increases in structural variability in corresponding
temporo-parietal projection areas. Confidence limits on 3D cortical
variation, visualized in 3D, exhibited severe increases in AD from 2 to 4
mm at the callosum to a peak SD of 19.6 mm at the posterior left Sylvian
fissure. Normal Sylvian fissure asymmetries (right higher than left; P <
0.0005), mapped for the first time in three dimensions, were accentuated in
AD (P < 0.0002), and were greater in AD than in controls (P < 0.05).
Severe AD-related increases in 3D variability and asymmetry may reflect
disease-related disruption of the commissural system connecting bilateral
temporal and parietal cortical zones, regions known to be at risk of early
metabolic dysfunction, perfusion deficits and selective neuronal loss in
AD.
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Tumors of the eyelids and their treatment by radiotherapy 总被引:3,自引:0,他引:3
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The Medicare Utilization Review Committee conducted a survey to determine the use of drugs with anticholinergic effects in confused elderly nursing home patients. Twenty-nine patients (34.5 percent) were receiving anticholinergic drugs, predominantly from the antidepressant and antipsychotic class. Thioridazine (Mellaril) was the most frequently used antipsychotic. No patients received higher than the equivalent recommended daily dose of atropine when calculated in terms of relative anticholinergic potency. No statistically significant correlation could be found between the presence of confusion and the amount of anticholinergics administered. Confusion and cognitive deterioration frequently are encountered when caring for aged patients. Clinical experience and recent studies suggest that anticholinergics may increase the risk of or exacerbate existing confusion, and this possible effect of anticholinergic activity should be considered when prescribing for elderly patients. 相似文献