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Background and Purpose-Severe asymptomatic carotid stenosis has been associated with cognitive impairment, but it is unknown whether this association is attributable to effects on brain connectivity. We present cognitive network abnormalities in a group of patients at a presymptomatic stage. Methods-Seventeen patients with Ն70% asymptomatic stenosis of unilateral internal carotid artery were compared with 26 healthy controls utilizing a comprehensive neuropsychological battery, the dizziness handicap inventory, and multimodality neuroimaging including diffusion tensor imaging and resting-state functional connectivity magnetic resonance imaging. Longitudinally, assessments were completed in a subgroup of 10 patients at 3 months after carotid artery stenting. Results-Compared with the healthy controls, the patients had worse dizziness scores, poorer memory, complex visuo-spatial performances, and lower whole-brain mean fractional anisotropy. The Scheltens scores of leukoaraiosis/ infarction were not different between groups. Their seed-based functional connectivity magnetic resonance imaging showed marked decrements of interhemispheric and intrahemispheric, ipsilaterally to carotid stenosis, functional connectivity in the frontoparietal network. In the default mode network, the intrahemispheric functional connectivity was bilaterally impaired. Importantly, the disrupted mean fractional anisotropy in the patients significantly correlated with the attention and verbal memory functions. After successful carotid artery stenting, small but measurable increments of the mean fractional anisotropy and little functional connectivity in the default mode network ipsilateral-to-carotid artery stenting were noted. Conclusions-We identified for the first time distinct patterns of network disruption that correlate with cognitive fragility in patients with asymptomatic carotid stenosis. Brain connectivity may provide early and useful biomarkers for brain ischemia and reperfusion. (Stroke. 2012;43:2567-2573.)Key Words: asymptomatic carotid stenosis Ⅲ cognitive impairment Ⅲ diffusion tensor imaging Ⅲ endovascular treatment Ⅲ functional connectivity magnetic resonance imaging Ⅲ resting state Ⅲ stent A symptomatic stenosis of the internal carotid artery (ICA) is described as significant atherosclerosis without stroke or transient ischemic attack in the brain or eyes. 1 Retrospective studies comparing asymptomatic subjects with and without ultrasound-assessed carotid stenosis have shown that subjects with carotid stenosis had significantly poorer performance in tests of attention, psychomotor speed, and memory. [2][3][4] Moreover, severe ICA stenosis (Ն50%) has been associated with a higher prevalence of silent cerebral infarcts and white matter hyperintensities, 3 indicating that "asymptomatic" carotid stenosis may not be truly asymptomatic. To understand the pathological changes after chronic cerebral hypoperfusion, experimental models of vascular cognitive impairment have been induced by bilateral 5 or unilateral 6 common carotid a...

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BACKGROUND AND PURPOSE: Asymptomatic carotid stenosis of Ն70% increases the incidence of microembolism and/or chronic hypoperfusion, which may consequently impair neurocognition and brain connections. We sought controlled evidence for any cognitive benefit of aggressive medical therapy and combined carotid revascularization.

Background Recent research has documented structural brain abnormalities in various criminal offenders. However, there have been few brain imaging studies of sex offenders, and none on white matter integrity. The current study tested the hypothesis that rapists, when compared to matched controls, would show abnormal cortical and subcortical white matter integrity.ResultsRapists showed significantly increased fractional anisotropy in the internal capsul e in the thalamus, caudate, and globus pallidus, and also in white matter tracts near the angular gyrus, posterior cingulate, frontal pole, lateral occipital cortex, and genu compared to controls matched for age, gender, and educational status. Reduced fractional anisotropy was observed in rapists in the posterior cingulum and in the inferior fronto-occipital fasciculus.ConclusionsTo our knowledge, this is the first study indicating white matter abnormalities in rapists. Findings indicate abnormalities in white matter connectivity in brain regions involved in reward/motivation and moral judgment, which may predispose rapists to be both over-responsive to sexual reward stimuli and also to make inappropriate moral decisions.