Corrigendum to "Developmental synergy between thalamic structure and interhemispheric connectivity in the visual system of preterm infants" [NeuroImage: Clinical 8 (2015) 462-472].

[This corrects the article DOI: 10.1016/j.nicl.2015.05.014.].

Evidence of abnormal amygdala functioning in borderline personality disorder: a functional MRI study.

BACKGROUND: Intense and rapidly changing mood states are a major feature of borderline personality disorder (BPD); however, there have only been a few studies investigating affective processing in BPD, and in particular no neurofunctional correlates of abnormal emotional processing have been identified so far. METHODS: Six female BPD patients without additional major psychiatric disorder and six age-matched female control subjects underwent functional magnetic resonance imaging (fMRI) to measure regional cerebral hemodynamic changes following brain activity when viewing 12 standardized emotionally aversive slides compared to 12 neutral slides, which were presented in random order. RESULTS: Our main finding was that BPD subjects but not control subjects were characterized by an elevated blood oxygenation level dependent fMRI signal in the amygdala on both sides. In addition, activation of the medial and inferolateral prefrontal cortex was seen in BPD patients. Both groups showed activation in the temporo-occipital cortex including the fusiform gyrus in BPD subjects but not in control subjects. CONCLUSIONS: Enhanced amygdala activation in BPD is suggested to reflect the intense and slowly subsiding emotions commonly observed in response to even low-level stressors. Borderline subjects' perceptual cortex may be modulated through the amygdala leading to increased attention to emotionally relevant environmental stimuli.

Functional MRI for presurgical planning: problems, artefacts, and solution strategies.

OBJECTIVES: Presurgical mapping of motor function is a widely used clinical application of functional (f) MRI, employing the blood oxygenation level dependent contrast. The aim of this study was to report on 3 years experience of 194 fMRI studies on the representation of motor function in 103 patients and to describe the problems and artefacts that were typically present. METHODS: An evaluation was carried out to determine whether the patients' age, type or location of the tumourous lesion, severity of the paresis, or the tasks used during the investigation have an effect on artefacts of fMRI studies and how these artefacts are best overcome. RESULTS: Functional MRI identified the motor regions in 85% of all investigated paradigms. In 11% of the investigated patients no information at all on functional localisation was obtained. A draining vein within the central sulcus was present in all patients that showed activation within the parenchyma of the precentral gyrus but also in three patients in whom no parenchymal activation was present. Head movement artefacts were the most frequent cause for fMRI failure, followed by low signal to noise ratio. Motion artefacts were correlated with the degree of paresis and with the functional task. Tasks involving more proximal muscles led to significantly more motion artefacts when compared with tasks that primarily involved distal muscles. Mean MR signal change during task performance was 2.5%. CONCLUSIONS: Most of the artefacts of functional MRI can be reliably detected and at least in part be reduced or eliminated with the help of mathematical algorithms, appropriate pulse sequences and tasks, and-probably most important-by evaluating the fMRI raw data-that is, the MR signal time courses.

Effects of blood estrogen level on cortical activation patterns during cognitive activation as measured by functional MRI.

Modulation of the blood estrogen level as it occurs during the menstrual cycle has a strong influence on both neuropsychological and neurophysiological parameters. One of currently preferred hypotheses is that the menstrual cycle hormones modulate functional hemispheric lateralization. We examined six male and six female subjects by functional magnetic resonance imaging (fMRI) to image cortical activation patterns associated with cognitive and motor activation to determine whether these changes during the menstrual cycle can be visualized. Female subjects, who did not use oral contraceptives, were scanned twice, once during the menses and once on the 11/12 day of the menstrual cycle. A word-stem-completion task, a mental rotation task and a simple motor task were performed by all subjects. Our data provide evidence that the menstrual cycle hormones influence the overall level of cerebral hemodynamics to a much stronger degree than they influence the activation pattern itself. No differences were seen between male subjects and female subjects during the low estrogen phase. During both neuropsychological tasks blood estrogen level had a profound effect on the size but not on the lateralization or the localization of cortical activation patterns. The female brain under estrogen showed a marked increase in perfusion in cortical areas involved in both cognitive tasks, whereas the hemodynamic effects during the motor tasks were less pronounced. This might be due to differences in neuronal or endothelian receptor concentration, differences in synaptic function, or, most likely, changes in the cerebrovascular anatomy in different cortical regions.

Hemispheric lateralization at different levels of human auditory word processing: a functional magnetic resonance imaging study.

We used functional magnetic resonance imaging to disentangle the functional anatomy of brain systems involved in the processing of auditory word form and meaning. Three monitoring tasks on auditory stimuli, aimed at phonetic, lexical and semantic processing, were used. We found no lateralization of temporal lobe activations, when word processing was contrasted versus the complex phonetic task. Bilateral middle temporal activations (Brodmann Area [BA] 21) were attributed to processing of word-form. Areas specific to semantic processing were restricted to the left hemisphere: the posterior middle frontal (BA 9) and posterior parietal (BA 7/40) cortex, as well as an inferior temporal area (BA 20/21). Our data suggest, that left hemispheric dominance for auditory word comprehension occurred at the level of semantic processing.

Cortical activation patterns during complex motor tasks in piano players and control subjects. A functional magnetic resonance imaging study.

We performed functional magnetic resonance imaging (MRI) in professional piano players and control subjects during an overtrained complex finger movement task using a blood oxygenation level dependent echo-planar gradient echo sequence. Activation clusters were seen in primary motor cortex, supplementary motor area, premotor cortex and superior parietal lobule. We found significant differences in the extent of cerebral activation between both groups with piano players having a smaller number of activated voxels. We conclude that, due to long-term motor practice a different cortical activation pattern can be visualized in piano players. For the same movements lesser neurons need to be recruited. The different volume of the activated ortical areas might therefore reflect the different effort necessary for motor performance in both groups.

MR blood oxygenation level-dependent signal differences in parenchymal and large draining vessels: implications for functional MR imaging.

BACKGROUND AND PURPOSE: One major limitation of current functional MR (fMR) imaging is its inability to clarify the relationship between sites of cortical neuronal activation, small parenchymal venules that are in close proximity to these sites, and large draining veins distant from the active parenchyma. We propose to use gradient-echo blood oxygenation level-dependent (BOLD) fMR time courses to differentiate large draining veins from parenchymal microvasculature. METHODS: In eight research subjects, five of whom presented with space-occupying lesions near the central sulcus, gradient-echo fMR imaging was performed during alternating periods of rest and motor activation. MR signal time courses from parenchymal regions and draining veins of different diameters, which were identified using contrast-enhanced T1-weighted scans, were evaluated. Percent signal changes (deltaS) and the time to the onset of MR signal rise (T0) were calculated. RESULTS: Mean delta(S) for all subjects was 2.3% (SD+/-0.7%) for parenchymal activation, 4.3% (SD +1.0%) for sulcal macrovasculature, and 7.3 (SD+/-1.1%) for large superficial bridging veins. The mean time to onset of MR signal increase was 4.4 seconds for parenchymal task-related hemodynamic changes and 6.6 seconds for venous hemodynamic changes, regardless of vessel size. Both the differences in delta(S) and T0 were statistically significant between venous and parenchymal activation (P < .0001). CONCLUSION: Gradient-echo fMR imaging reveals hemodynamic task-related changes regardless of vessel size and therefore might show macrovascular changes distal to the site of neuronal activity. MR-signal time-course characteristics (delta(S) and T0) can be used to differentiate between small parenchymal and larger pial draining vessels, which is especially important in presurgical planning of neurosurgical procedures involving functionally important brain regions. The knowledge about the differences in (delta)S and T0 between micro- and macrovasculature might lead to a more accurate description of the spatial distribution of underlying neuronal activity.