Microbleeds do not affect rate of cognitive decline in Alzheimer disease.
ABSTRACT Editors' Note: Dr. Martinez-Ramirez et al. comment on study limitations that might have led to the authors' conclusions in "Microbleeds do not affect rate of cognitive decline in Alzheimer disease." Dr. Vanacore, in reference to "Neurodegenerative causes of death among retired National Football League players," raises the 12-fold higher risk of death from ALS in professional Italian soccer players, specifically midfielders, and calls for further cohort studies in other professional athletes.
Full-textDOI: · Available from: Sergi Martinez-Ramirez, Apr 26, 2015
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ABSTRACT: Micro-hemorrhages are a common result of traumatic brain injury (TBI), which can be quantified with susceptibility weighted imaging and mapping (SWIM), a quantitative susceptibility mapping (QSM) approach. 23 TBI patients (5 women,18 men; median 41.25 years old, range 21.69-67.75 years) with an average Glasgow Coma Scale score of 7 (range 4-14) at admission were recruited at mean 149 (range 57-366) days after injury. Susceptibility-weighted imaging (SWI) data were collected and post-processed to create SWIM images. The susceptibility value of small hemorrhages (diameter ≤10 mm) and major deep veins (right septal, left septal, central septal, right thalamostriate, left thalamostriate, internal cerebral, right basal vein of Rosenthal, left basal vein of Rosenthal, and pial veins) were evaluated. Different susceptibility thresholds were tested to determine SWIM's sensitivity and specificity for differentiating hemorrhages from the veins. 253 deep veins and 173 small hemorrhages were identified and evaluated. The mean susceptibility of hemorrhages was 435±206 parts per billion (ppb) and the mean susceptibility of deep veins was 108±56 ppb . Hemorrhages showed a significantly higher susceptibility than all deep veins (p＜0.001). With different thresholds (250, 227 and 200 ppb), the specificity ranged from 97% to 95% to 92% and sensitivity ranged from 84% to 90% to 92%, respectively. These results show that SWIM could be used to differentiate hemorrhages from veins in TBI patients in a semi-automated manner with reasonable sensitivity and specificity. A larger cohort will be needed to validate these findings.Journal of neurotrauma 03/2015; DOI:10.1089/neu.2014.3856 · 3.97 Impact Factor
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ABSTRACT: Cerebral microbleeds (CMBs) are considered to be a novel marker of cerebral small vessel disease. However, the link with cognitive impairment remains unclear. We investigated whether CMBs-independent of other traditional markers of cerebral small vessel disease-are related to cognition. Chinese subjects from the population-based Singapore Chinese Eye Study, who failed an initial cognitive screening and were recruited into the ongoing Epidemiology of Dementia in Singapore Study, underwent neuropsychological testing and 3 T brain magnetic resonance imaging. The presence and number of CMBs were graded using Brain Observer Microbleed Scale on susceptibility-weighted images. Other magnetic resonance imaging lesions that were graded included presence of lacunes, white matter lesion, and total brain volumes. A comprehensive neuropsychological battery was administered and cognitive function was summarized as composite and domain-specific Z-scores. Among 282 subjects, 91 had any CMBs (32.3%), of whom 36 (12.8%) had multiple CMBs. CMBs were-independent of cardiovascular risk factors and other markers of cerebral small vessel disease-significantly associated with poorer cognitive function as reflected by composite Z-score (mean difference per CMB increase: -0.06; 95% confidence interval: -0.11, -0.01] and with domain-specific Z-scores including executive function, attention, and visuoconstruction. Among Chinese subjects CMBs were, independent of other concomitant markers of cerebral small vessel disease, associated with poorer cognitive function.Alzheimer disease and associated disorders 12/2013; DOI:10.1097/WAD.0000000000000015 · 2.69 Impact Factor