Showing papers by "Mark A. van Buchem published in 2013"

Neuroimaging standards for research into small vessel disease and its contribution to ageing and neurodegeneration

Abstract: Cerebral small vessel disease (SVD) is a common accompaniment of ageing. Features seen on neuroimaging include recent small subcortical infarcts, lacunes, white matter hyperintensities, perivascular spaces, microbleeds, and brain atrophy. SVD can present as a stroke or cognitive decline, or can have few or no symptoms. SVD frequently coexists with neurodegenerative disease, and can exacerbate cognitive deficits, physical disabilities, and other symptoms of neurodegeneration. Terminology and definitions for imaging the features of SVD vary widely, which is also true for protocols for image acquisition and image analysis. This lack of consistency hampers progress in identifying the contribution of SVD to the pathophysiology and clinical features of common neurodegenerative diseases. We are an international working group from the Centres of Excellence in Neurodegeneration. We completed a structured process to develop definitions and imaging standards for markers and consequences of SVD. We aimed to achieve the following: first, to provide a common advisory about terms and definitions for features visible on MRI; second, to suggest minimum standards for image acquisition and analysis; third, to agree on standards for scientific reporting of changes related to SVD on neuroimaging; and fourth, to review emerging imaging methods for detection and quantification of preclinical manifestations of SVD. Our findings and recommendations apply to research studies, and can be used in the clinical setting to standardise image interpretation, acquisition, and reporting. This Position Paper summarises the main outcomes of this international effort to provide the STandards for ReportIng Vascular changes on nEuroimaging (STRIVE).

Enhanced amygdala reactivity to emotional faces in adults reporting childhood emotional maltreatment

Abstract: In the context of chronic childhood emotional maltreatment (CEM; emotional abuse and/or neglect), adequately responding to facial expressions is an important skill. Over time, however, this adaptive response may lead to a persistent vigilance for emotional facial expressions. The amygdala and the medial prefrontal cortex (mPFC) are key regions in face processing. However, the neurobiological correlates of face processing in adults reporting CEM are yet unknown. We examined amydala and mPFC reactivity to emotional faces (Angry, Fearful, Sad, Happy, Neutral) vs scrambled faces in healthy controls and unmedicated patients with depression and/or anxiety disorders reporting CEM before the age of 16 years (n = 60), and controls and patients who report no childhood abuse (n = 75). We found that CEM was associated with enhanced bilateral amygdala reactivity to emotional faces in general, and independent of psychiatric status. Furthermore, we found no support for differential mPFC functioning, suggesting that amygdala hyper-responsivity to emotional facial perception in adults reporting CEM may be independent from top-down influences of the mPFC. These findings may be key in understanding the increased emotional sensitivity and interpersonal difficulties, that have been reported in individuals with a history of CEM.

Functional brain connectivity at rest changes after working memory training.

Abstract: Networks of functional connectivity are highly consistent across participants, suggesting that functional connectivity is for a large part predetermined. However, several studies have shown that functional connectivity may change depending on instructions or previous experience. In the present study, we investigated whether 6 weeks of practice with a working memory task changes functional connectivity during a resting period preceding the task. We focused on two task-relevant networks, the frontoparietal network and the default network, using seed regions in the right middle frontal gyrus (MFG) and the medial prefrontal cortex (PFC), respectively. After practice, young adults showed increased functional connectivity between the right MFG and other regions of the frontoparietal network, including bilateral superior frontal gyrus, paracingulate gyrus, and anterior cingulate cortex. In addition, they showed reduced functional connectivity between the medial PFC and right posterior middle temporal gyrus. Moreover, a regression with performance changes revealed a positive relation between performance increases and changes of frontoparietal connectivity, and a negative relation between performance increases and changes of default network connectivity. Next, to study whether experience-dependent effects would be different during development, we also examined practice effects in a pilot sample of 12-year-old children. No practice effects were found in this group, suggesting that practice-related changes of functional connectivity are age-dependent. Nevertheless, future studies with larger samples are necessary to confirm this hypothesis. Hum Brain Mapp, 2011. © 2011 Wiley Periodicals, Inc.

Modulatory effects of the piccolo genotype on emotional memory in health and depression.

Abstract: Major depressive disorder (MDD) has been associated with biased memory formation for mood-congruent information, which may be related to altered monoamine levels. The piccolo (PCLO) gene, involved in monoaminergic neurotransmission, has previously been linked to depression in a genome-wide association study. Here, we investigated the role of the PCLO risk allele on functional magnetic resonance imaging (MRI) correlates of emotional memory in a sample of 89 MDD patients (64 PCLO risk allele carriers) and 29 healthy controls (18 PCLO risk allele carriers). During negative word encoding, risk allele carriers showed significant lower activity relative to non-risk allele carriers in the insula, and trend-wise in the anterior cingulate cortex and inferior frontal gyrus. Moreover, depressed risk allele carriers showed significant lower activity relative to non-risk allele carriers in the striatum, an effect which was absent in healthy controls. Finally, amygdalar response during processing new positive words vs. known words was blunted in healthy PCLO+ carriers and in MDD patients irrespective of genotype, which may indicate that signalling of salient novel information does not occur to the same extent in PCLO+ carriers and MDD patients. The PCLO risk allele may increase vulnerability for MDD by modulating local brain function with regard to responsiveness to salient stimuli (i.e. insula) and processing novel negative information. Also, depression-specific effects of PCLO on dorsal striatal activation during negative word encoding and the absence of amygdalar salience signalling for novel positive information further suggest a role of PCLO in symptom maintenance in MDD.

Influence of COMT val158met Genotype on the Depressed Brain during Emotional Processing and Working Memory

Abstract: Major depressive disorder (MDD) has been associated with abnormal prefrontal-limbic interactions and altered catecholaminergic neurotransmission. The val158met polymorphism on the catechol-O-methyltransferase (COMT) gene has been shown to influence prefrontal cortex (PFC) activation during both emotional processing and working memory (WM). Although COMT-genotype is not directly associated with MDD, it may affect MDD pathology by altering PFC activation, an endophenotype associated with both COMT and MDD. 125 participants, including healthy controls (HC, n=28) and MDD patients were genotyped for the COMT val158met polymorphism and underwent functional magnetic resonance imaging (fMRI-neuroimaging) during emotion processing (viewing of emotional facial expressions) and a WM task (visuospatial planning). Within HC, we observed a positive correlation between the number of met-alleles and right inferior frontal gyrus activation during emotional processing, whereas within patients the number of met-alleles was not correlated with PFC activation. During WM a negative correlation between the number of met-alleles and middle frontal gyrus activation was present in the total sample. In addition, during emotional processing there was an effect of genotype in a cluster including the amygdala and hippocampus. These results demonstrate that COMT genotype is associated with relevant endophenotypes for MDD. In addition, presence of MDD only interacts with genotype during emotional processing and not working memory.

Lower susceptibility to cerebral small vessel disease in human familial longevity: the Leiden Longevity Study

Abstract: BACKGROUND AND PURPOSE On MRI, cerebral white matter lesions, lacunar infarcts, and cerebral microbleeds are common imaging correlates of cerebral small vessel damage in apparently healthy elderly individuals. We investigated whether middle-aged to elderly offspring of nonagenarian siblings, who are predisposed to become long-lived as well, have a lower prevalence of white matter lesions, lacunar infarcts, and cerebral microbleeds than control subjects. METHODS All subjects were from the Leiden Longevity Study. In this study, middle-aged to elderly offspring of nonagenarian siblings, who are predisposed to become long-lived as well, were contrasted to their spouses. Cerebral small vessel disease was assessed using 3-T MRI. RESULTS Offspring were less likely to have severe periventricular frontal caps (odds ratio [OR], 0.3; 95% confidence interval [CI], 0.1-1.1; P trend=0.01) and severe periventricular bands (OR, 0.4; 95% CI, 0.2-0.8; P trend=0.02). Moreover, offspring were less likely to have frontal (OR, 0.4; 95% CI, 0.2-0.9; P trend=0.05), parietal (OR, 0.4; 95% CI, 0.1-0.9; P trend=0.001), temporal (OR, 0.3; 95% CI, 0.1-0.8]; P trend=0.004), and occipital subcortical white matter lesions (OR, 0.3; 95% CI, 0.1-0.6; P trend=0.001). Prevalence of lacunar infarcts also was lower in offspring (OR, 0.3; 95% CI, 0.1-1.1; P=0.07). Prevalence of microbleeds was not significantly different in offspring and control subjects. CONCLUSIONS Exceptional familial longevity is associated with a lower susceptibility to white matter lesions and lacunar infarcts, but not cerebral microbleeds.

Family history of alcohol dependence and gray matter abnormalities in non-alcoholic adults

Abstract: Objectives. Alcohol-use disorders in adolescents are associated with gray matter (GM) abnormalities suggesting neurotoxicity by alcohol. However, recently similar GM abnormalities were found in non-drinking children with a family history (FH) of alcohol dependence (AD). The question thus rises whether these abnormalities represent a transient delay in brain maturation or a persistent risk factor for developing neuropsychiatric disorders, rather than a (neurotoxic) consequence of AD. This study investigated whether a FH of AD in non-drinking adults is associated with abnormal GM-volumes similar to those observed in drinking and non-drinking adolescents with a FH of AD. Methods. GM-images were analyzed using Voxel-Based Morphometry in non-alcoholics with (FH+; N = 36) and without (FH–; N = 107) familial AD. Additionally we controlled for possible confounders: diagnosis of depression/anxiety, childhood trauma and familial depression/anxiety. Results. Smaller GM-volumes were shown in the right parahip...

Deformation texture-based features for classification in Alzheimer's disease

Abstract: Neurological pathologies are often reflected in brain magnetic resonance images as abnormal global or local anatomical changes. These variations can be computed using non-rigid registration and summarized using Jacobian determinant maps of the resulting deformation field, which characterise local volume changes. We propose a new approach which exploits the information contained in Jacobian determinant maps of the whole brain in Alzheimer’s disease (AD) classification by means of texture analysis. Textural features were derived from whole-brain Jacobian determinant maps based on 3D Grey Level Co-occurrence Matrix. The large number of features obtained depicts anatomical variations at different resolution, allowing retaining both global and local information. Principle component analysis was applied for feature reduction such that 95% of the data variance was retained. Classification was performed using a linear support vector machine. We evaluated our approach using a bootstrapping procedure in which 92 subjects were randomly split into separate training and testing sets. For comparison purposes, we implemented two dissimilarity-based classification approaches, one based on pairwise registration and the other based on registration to a single template. Our new approach significantly outperformed the other approaches. The results of this study showed that pairwise registration did not bring added value compared to registration to a single template and textural features were more informative than dissimilarity-based features. This study demonstrates the potential of texture analysis on whole brain Jacobian determinant map for diagnosis of AD subjects.