Large-scale network dysfunction in vascular cognitive disorder supports connectional diaschisis in advanced arteriosclerosis.

BACKGROUND AND PURPOSE: The interrelation of cognitive performance, cerebrovascular damage and brain functional connectivity (FC) in advanced arteriosclerosis remains unclear. Our aim was to investigate the associations between FC, white matter damage and cognitive impairment in carotid artery disease. METHODS: Seventy-one participants with a recent cerebrovascular event and with written informed consent underwent resting-state functional magnetic resonance imaging and the Addenbrooke's Cognitive Examination - Revised (ACE-R). Network and inter-hemispheric FC metrics were compared between cognitively normal and impaired subjects, and interrelated with cognition. In order to explore the nature of FC changes, their associations with microstructural damage of related white matter tracts and cognitive performance were investigated, followed by mediation analysis. RESULTS: Participants with global cognitive impairment showed reduced FC compared to the cognitively intact subjects within the central executive network (CEN), and between hemispheres. Patients with executive dysfunction had decreased CEN FC whilst patients with memory loss demonstrated low FC in both the CEN and the default mode network (DMN). Global performance correlated with connectivity metrics of the CEN hub with DMN nodes, and between hemispheres. Cingulum mean diffusivity (MD) was negatively correlated with ACE-R and CEN-DMN FC. The cingulum MD-cognition association was partially mediated by CEN-DMN FC. CONCLUSIONS: Long-range functional disconnection of the CEN with DMN nodes is the main feature of cognitive impairment in elderly subjects with symptomatic carotid artery disease. Our findings provide further support for the connectional diaschisis concept of vascular cognitive disorder, and highlight a mediation role of functional disconnection to explain associations between microstructural white matter tract damage and cognitive impairment.

Mesiotemporal atrophy and hippocampal diffusivity distinguish amnestic from non-amnestic vascular cognitive impairment.

BACKGROUND AND PURPOSE: The role of clinical factors, cerebral infarcts and hippocampal damage in vascular cognitive impairment (VCI) subtypes remains unclear. METHODS: Non-demented patients with carotid stenosis and recent transient ischemic attack/stroke had cognitive assessment and brain magnetic resonance imaging (MRI). Amnestic VCI was defined as memory impairment; non-amnestic VCI was any other subdomain impairment. Associations of MRI metrics [log-transformed total ischemic lesion load (log TILL), mesiotemporal atrophy (MTA) score, hippocampal mean diffusivity (hipMD)] with cognitive performance were assessed. RESULTS: A hundred and eight patients, 47 with amnestic VCI and 21 with non-amnestic VCI, were assessed. A higher MTA (odds ratio 12.89, P = 0.001) and left hipMD (odds ratio 4.43, P = 0.003) contributed to amnestic VCI versus normal. Age-adjusted fluency correlated with log TILL (P = 0.002). Age-adjusted memory was associated with left hipMD (P = 0.001), MTA (P < 0.001) but not log TILL (P = 0.14). Left hipMD, MTA and smoking showed classification potential between amnestic VCI versus normal (area 0.859, P < 0.001). CONCLUSIONS: Neuroimaging assists stratification in amnestic VCI characterized by hippocampal changes and in non-amnestic VCI by higher ischemic burden. MTA and hippocampal diffusivity show diagnostic biomarker potential.

MR imaging-detected carotid plaque hemorrhage is stable for 2 years and a marker for stenosis progression.

BACKGROUND AND PURPOSE: MR imaging-detected carotid plaque hemorrhage is associated with an increased risk of recurrent ischemic cerebrovascular events and could be an indicator of disease progression; however, there are limited data regarding the dynamics of the MR imaging-detected carotid plaque hemorrhage signal. We assessed the temporal change of this signal and its impact on carotid disease progression. MATERIALS AND METHODS: Thirty-seven symptomatic patients with 54 carotid stenoses of >30% on sonography underwent serial MR imaging during 24 months. A signal-intensity ratio of >1.5 between the carotid plaque and adjacent muscle was defined as plaque hemorrhage, and a change in signal-intensity ratio of >0.31 between time points was considered significant. Sixteen patients underwent ≥2 carotid sonography scans to determine the peak systolic velocities and degree of stenosis with time. RESULTS: Of the 54 carotids, 28 had the presence of hyperintense signal on an MR imaging sequence (PH+) and 26 had the absence of hyperintense signal on an MR imaging sequence (PH-) at baseline. The signal-intensity ratio was stable in 33/54 carotid plaques, but 39% showed a change. Plaque hemorrhage classification did not change in 87% of carotid plaques, but 4 became PH+, and 3, PH-. As a group, PH+ carotids did not change significantly in signal-intensity ratio (P = .585), whereas PH- showed an increased signal-intensity ratio at 24.5 months (P = .02). In PH+ plaques, peak systolic velocities significantly increased by 22 ± 39.8 cm/s from baseline to last follow-up sonography (Z = 2.427, P = .013). CONCLUSIONS: During 2 years, MR imaging-detected carotid plaque hemorrhage status remained stable in most (87%) cases with 4 (7%) incident plaque hemorrhages. PH+ plaques were associated with increased flow velocity during the follow-up period.

Some normative data on the Bender Gestalt test performance of Iranian children.

The Bender Gestalt test of visuomotor coordination was applied to a sample of Iranian children (N = 1,600) aged between 6.0 years and 10 years and 11 months attending grades 1 through 5 of 16 public primary schools in Shiraz city, southern Iran. The administration of the test and its scoring followed the standard procedures recommended by Koppitz. The reliability of the test in its new context was investigated through readministering it to a group of 60 children after four weeks, the r being .77. The validity of the test was established by comparing scores of children at different age levels and by correlating test results with marks obtained in two sets of examinations, results of Goodenough Harris Draw-A-Person Test and indices of parental education and occupation. The results are mostly in the expected direction and indicate that the Bender Gestalt test may be used as a simple measure of cognitive-intellectual development in Iran. Observed differences between Iranian norms and those of Koppitz (1963, 1975) for American children are briefly discussed and explained.

A clinical evaluation of root resorption by formocresol treatment in 120 cases of pulpotomy in permanent molars.

The effect of a formocresol pulpotomy of a 120 permanent molar showed external and internal resorption on distal root in lower molar, and palatal root in the upper molar. In this study 33.3% were male and 66.7% were female. The age distribution of patients was 16 to 20 years of age and 21 to 25 years of age. The rate of resorption for chronic pulpitis was more than acute pulpitis. The success of formocresol pulpotomy treatment at the end of the 10th year for acute pulpitis was 92.26% in contrast to 84% for chronic pulpitis.