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Peter Stoeter

Publications and source records attributed to Peter Stoeter.

At least 19 recordsLinked to original sources
PubMed2007

'Prefrontal' cognitive performance of healthy subjects positively correlates with cerebral FDOPA influx: an exploratory [18F]-fluoro-L-DOPA-PET investigation.

Dopamine neurotransmission influences those cognitive processes, which are generally regarded as prefrontal cortical functions. In previous positron-emission-tomography (PET) studies, net blood-brain clearance of [18F]-fluoro-l-DOPA (FDOPA) correlated with impaired cognitive performance in patients with Parkinson's disease or schizophrenia. We hypothesized that FDOPA influx also correlates with performance of cognitive tasks associated with prefrontal functioning in healthy volunteers. The net blood-brain clearance of FDOPA (K(in)(app)) was mapped in a group of 11 healthy volunteers and calculated in striatal volumes-of-interest. The Wisconsin-Card-Sorting-Test (WCST), Stroop-Test, Trail-Making-Test (TMT-A/B), and Continuous-Performance-Test (CPT-M) had been administered previously to the same subjects. No correlation of K(in) (app) with perseverative errors in WCST or age could be found. However, there were significant positive correlations between the magnitude of K(in)(app) in caudate nucleus, putamen, and midbrain with performance of the TMT-B, CPT-M, and the Stroop test. Highest correlations were found between the time needed to perform the Stroop interference task and the K(in)(app) of striatal areas (Caudate nucleus: -0.780, P = 0.005; putamen: -0.870, P < 0. 001). Thus, the present findings reveal a strong correlation between dopamine synthesis capacity in striatum of healthy volunteers and performance of cognitive tasks linked to the prefrontal cortex.

Adult↗
PubMed2007

White matter fiber tracking computation based on diffusion tensor imaging for clinical applications.

Fiber tracking allows the in vivo reconstruction of human brain white matter fiber trajectories based on magnetic resonance diffusion tensor imaging (MR-DTI), but its application in the clinical routine is still in its infancy. In this study, we present a new software for fiber tracking, developed on top of a general-purpose DICOM (digital imaging and communications in medicine) framework, which can be easily integrated into existing picture archiving and communication system (PACS) of radiological institutions. Images combining anatomical information and the localization of different fiber tract trajectories can be encoded and exported in DICOM and Analyze formats, which are valuable resources in the clinical applications of this method. Fiber tracking was implemented based on existing line propagation algorithms, but it includes a heuristic for fiber crossings in the case of disk-shaped diffusion tensors. We successfully performed fiber tracking on MR-DTI data sets from 26 patients with different types of brain lesions affecting the corticospinal tracts. In all cases, the trajectories of the central spinal tract (pyramidal tract) were reconstructed and could be applied at the planning phase of the surgery as well as in intraoperative neuronavigation.

Adolescent↗
PubMed2006

Asymmetry in dopamine D(2/3) receptors of caudate nucleus is lost with age.

Molecular and functional imaging techniques reveal evidence for lateralization of human cerebral function. Based on animal data, we hypothesized that asymmetry in dopamine neurotransmission declines during normal aging. In order to test this hypothesis, we measured dopamine D2/3 receptor availability with [18F]desmethoxyfallypride-PET (DMFP) in putamen and caudate nucleus (NC) of 21 healthy, right-handed males (24-60 years; 35+/-10). For volumetric analysis, high-resolution T1-weighted MR-images were obtained in 18 of the PET-subjects in order to assess possible age-related decreases in NC and putamen volume. The calculated DMFP binding potentials (BP) showed a right-ward asymmetry in NC of young subjects that decreased with age (r = 0.577, p = 0.006; Pearson correlation; two-tailed). An age-independent analysis showed a right-ward asymmetry in NC of the whole subject group (left: 1.49+/-0.35; right: 1.65+/-0.43 [mean+/-S.D.]; p = 0.020). No such side lateralization or age-effects could be found in the putamen. Volumes tended to be asymmetric in the putamen (right: 4.85+/-0.56 cm3; left: 4.64+/-0.86 cm3 [mean+/-S.D.]; p = 0.063), but not in NC. The decline of putamen volume during aging was significant in the right putamen (r = -0.613; p = 0.007; Pearson correlation; two-tailed). There were no other significant correlations between striatal volumes and age or BP. Because ventral striatal dopamine neurotransmission is involved in cognitive processes, this loss of physiological asymmetry in NC dopamine transmission during aging might be involved in age-related declines of cognitive performance.

Adult↗
PubMed2006

Smoking impacts on prefrontal attentional network function in young adult brains.

RATIONALE: There is abundant evidence from clinical and preclinical studies that acute administration of nicotine has beneficial effects on attentional network function in the brain. In contrast, little is known about potentially neurotoxic effects on the attentional network during neurodevelopmentally critical periods, such as during adolescence and early adulthood. METHODS: Using event-related functional MRI (fMRI), we investigated prefrontal attentional network function in young adults (n=15 regular smokers and n=12 never-smokers; age: 22.6+/-1.5 years). Duration of smoking was 6.9+/-2.3 years (range of 2-10). Smokers were allowed to smoke ad libitum before the fMRI scanning was conducted. RESULTS: As expected from literature, prefrontal attentional network activity was significantly reduced in smokers compared to nonsmokers (Z=2.1; P=0.036). In smokers, we found that the history of smoking duration (years) is directly related to the extent of diminished attentional network activity (R=-0.67; P=0.012). CONCLUSIONS: To our best knowledge, the relationship between the duration of smoking history and prefrontal attentional network function has not yet been reported. This finding might suggest that several years of chronic nicotine abuse may be sufficient to exert long-lasting effects on the brain function of adolescents and young adults.

Adolescent↗
PubMed2006

COMT genotype predicts BOLD signal and noise characteristics in prefrontal circuits.

OBJECTIVE: Prefrontal dopamine (DA) is catabolized by the COMT (catechol-O-methyltransferase) enzyme. Literature suggests that the Val/Met single nucleotide polymorphism (SNP) in the COMT gene predicts executive cognition in humans with Val carriers showing poorer performance due to less available synaptic DA. Recent fMRI studies are thought to agree with these studies having demonstrated prefrontal hyperactivation during n-back and attention-requiring tasks. This was interpreted as "less efficient" processing due to impaired signal-to-noise ratio (SNR) of neuronal activity. However, electrophysiological studies of neuronal SNR in primates and humans imply that prefrontal cortex should show a diminished prefrontal BOLD response in Val carriers. In the present study, we addressed the question of whether the prefrontal SNR of the BOLD response is decreased in Val carriers using a visual oddball task and an approach to analysis of fMRI data that maximizes noise characterization. METHODS: We investigated N=17 homozygous Met carriers compared with N=24 Val carriers matched for age, sex, education, IQ, reaction time (variability) and head motion. Event-related fMRI was conducted presenting 160 visual stimuli (40 targets, checkerboard reversal). Subjects had to respond as quickly as possible to targets by button press. In the fMRI GLM [y(t)=beta*x(t)+c+e(t)] analysis, voxel-by-voxel 'activation' [y(t)] as well as residual noise variance [e(t)=sigma2] were calculated using a conservative full-width half maximum (FWHM=6 mm). RESULTS: As compared to Val carriers, we observed a stronger and more extended BOLD responses in homozygous Met carriers in left supplementary motor area (SMA) extending to ACC and dorsolateral prefrontal cortex. Vice versa, increased levels of noise were seen in Val carriers surrounding the peak activation maximum. DISCUSSION: In line with our expectations from prior electrophysiological studies, we observed a diminished BOLD response and increased noise in Val carriers. This suggests that the DA stabilizes cortical microcircuits by sharpening the signal and suppressing surrounding noise.

Adult↗
PubMed2006

Brainstem and cerebellar fMRI-activation during horizontal and vertical optokinetic stimulation.

Animal studies have shown that not only cortical, but also brainstem and cerebellar areas are involved in the initiation and generation of optokinetic nystagmus (OKN), e.g., cortico-(pretecto)pontine-olivo-cerebellar pathways. The aim of this fMRI study was to identify and differentiate brainstem and cerebellar areas involved in horizontal and vertical OKN (h/vOKN) in humans. In a group of nine healthy volunteers, hOKN and vOKN were statistically compared with a stationary control condition. There were common activated regions for hOKN and vOKN directions located in the transition zone between the posterior thalamus and the mesencephalon bilaterally covering the pretectal nucleus complex, which is known to be a major structure within the afferent branch of the optokinetic system. Furthermore, during hOKN, activation occurred bilaterally in the mediodorsal and dorsolateral ponto-medullary brainstem, which could be best attributed to the reticular formation, especially the paramedian pontine reticular formation (PPRF). For vOKN, additional activated areas in the dorsal mesencephalic brainstem could be best localized to the ocular motor nuclei and the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF). For both OKN directions, the cerebellar activation was localized in the oculomotor vermis (declive VI, folium and tuber VIIA/B, in part pyramis VIIIA), and the flocculus bilaterally as well as widespread in the cerebellar hemispheres. In conclusion, fMRI allowed first attributions of neuronal substrates in the cerebellum and brainstem to hOKN and vOKN in humans. Consistent with the animal data, the dorsal ponto-medullary routes were involved bilaterally for hOKN, whereas the rostral mesencephalic routes were involved for vOKN.

Adult↗
PubMed2006

Diagnostic utility of hippocampal size and mean diffusivity in amnestic MCI.

Hippocampus atrophy is a frequent finding in mild cognitive impairment (MCI), whereas diffusion-tensor-imaging (DTI) has demonstrated its value to detect subtle brain tissue changes in several neuropsychiatric diseases including MCI. To compare the diagnostic accuracy of both methods, high resolution MRI scans for hippocampus volumetry, and co-registered DTI-scans for ROI-based mean diffusivity (MD) and fractional anisotropy (FA) were carried out in 18 patients with amnestic MCI (7 females, age 67.3+/-8.7 years, MMSE 25.2+/-2.2) and 18 controls (age 66.9+/-9.0 years, MMSE 28.7+/-1.0). Diagnostic properties of normalized hippocampus volume (HV) and DTI measures with regard to MCI status were estimated by receiver operating characteristics (ROC) analyses and logistic regression. Parameters of the left hippocampus showed superior predictive power when compared to the right. At a specificity set to 80%, left HV had low sensitivity (50%); left hippocampal MD values revealed superior sensitivity (89%), similar to left hippocampal FA (78%). The results demonstrate higher sensitivity of DTI-derived left hippocampal parameters than volume measures in detecting subtle hippocampal abnormalities related to MCI.

Aged↗
PubMed2006

Predicting conversion to dementia in mild cognitive impairment by volumetric and diffusivity measurements of the hippocampus.

In our prospective study of diffusion tensor imaging (DTI), we measured hippocampal mean diffusivity (MD) and volumes in amnestic mild cognitive impairment (MCI). Thirteen MCI patients were followed-up by clinical assessment over a mean 112-year period. MCI patients who converted to dementia (6 of 13) during the observation period had slightly elevated left hippocampal mean diffusivity at baseline compared with MCI patients who remained clinically stable. Hippocampal volumes as well as baseline verbal memory and MMSE did not differ significantly between stable MCI patients and converters. Hippocampal diffusivity was superior to hippocampal volumes for prediction of conversion to dementia in MCI patients during a 112-year period.

Aged↗
PubMed2006

Pattern of microstructural brain tissue alterations in Fabry disease: a diffusion-tensor imaging study.

Fabry disease (FD) is a lysosomal storage disorder that is associated with marked cerebrovascular disease. Conventional MRI shows a progressive load of white matter lesions (WMLs) due to cerebral vasculopathy in the course of FD. To quantify brain structural changes in clinically affected male and female patients with FD we performed a prospective Diffusion-Tensor Imaging (DTI) study in 27 adult Fabry patients (13m, 14f) and 21 age-matched controls (12 m, 9f). Global Mean Diffusivity (MD) was increased in FD (P = 0.003) whereas global Fractional Anisotropy (FA) did not differ significantly between FD and controls. Even FD patients without significant WMLs (9m, 9f) showed increased global MD (P = 0.004). Regions of interest with significant MD elevations were located in the frontal, parietal and temporal white matter. No differences of thalamic and hippocampal DTI measurements could be detected between FD and controls. DTI parameters did not differ between male and female patients. The data provide the first evidence of a pattern of marked structural brain tissue alterations in adult FD male and female patients even without WMLs. DTI seems to be an appropriate diagnostic tool to quantify brain tissue integrity in FD. Moreover, this method could be favorable for longitudinal assessment of brain structure alterations in FD, and for monitoring the cerebral effects of enzyme replacement therapy.

Adult↗
PubMed2006

Modulation of [18F]fluorodopa (FDOPA) kinetics in the brain of healthy volunteers after acute haloperidol challenge.

In animal studies, acute antipsychotic treatment was shown to enhance striatal DOPA-decarboxylase (DDC) activity. However, this phenomenon has not been demonstrated in humans by positron emission tomography (PET). Therefore, we investigated acute haloperidol effects on DDC activity in humans using [18F]fluorodopa (FDOPA) PET. Nine healthy volunteers were scanned with FDOPA in drug-free baseline conditions and after 3 days of haloperidol treatment (5 mg/day). A continuous performance test (CPT) was administered in both conditions. The net blood-brain clearance of FDOPA (K(in)app) in striatum, mesencephalon, and medial prefrontal cortex was calculated by volume-of-interest analysis. The macroparameter K(in)app is a composite of several kinetic terms defining the distribution volume of FDOPA in brain (V(e)D) and the relative activity of DOPA decarboxylase (k3D). Therefore, compartmental kinetic analysis was used to identify the physiological basis of the observed changes in K(in)app period. The magnitude of K(in)app was significantly increased in the putamen (18%) and mesencephalon (36%). Furthermore, V(e)D in the brain was increased by 15%. Increments of k3(D) in the basal ganglia did not attain statistical significance. The significant worsening of CPT results did not correlate with changes in FDOPA utilization. The present PET results indicate potentiation of FDOPA utilization in human basal ganglia by acute haloperidol treatment, apparently due to increased availability throughout the brain. The stimulation of DDC cannot be excluded due to insufficient statistical power in the estimation of k3(D) changes.

Adult↗
PubMed2006

Distributed BOLD-response in association cortex vector state space predicts reaction time during selective attention.

Human cortical information processing is thought to be dominated by distributed activity in vector state space (Churchland, P.S., Sejnowski, T.J., 1992. The Computational Brain. MIT Press, Cambridge.). In principle, it should be possible to quantify distributed brain activation with independent component analysis (ICA) through vector-based decomposition, i.e., through a separation of a mixture of sources. Using event-related functional magnetic resonance imaging (fMRI) during a selective attention-requiring task (visual oddball), we explored how the number of independent components within activated cortical areas is related to reaction time. Prior to ICA, the activated cortical areas were determined on the basis of a General linear model (GLM) voxel-by-voxel analysis of the target stimuli (checkerboard reversal). Two activated cortical areas (temporoparietal cortex, medial prefrontal cortex) were further investigated as these cortical regions are known to be the sites of simultaneously active electromagnetic generators which give rise to the compound event-related potential P300 during oddball task conditions. We found that the number of independent components more strongly predicted reaction time than the overall level of "activation" (GLM BOLD-response) in the left temporoparietal area whereas in the medial prefrontal cortex both ICA and GLM predicted reaction time equally well. Comparable correlations were not seen when principle components were used instead of independent components. These results indicate that the number of independently activated components, i.e., a high level of cortical activation complexity in cortical vector state space, may index particularly efficient information processing during selective attention-requiring tasks. To our best knowledge, this is the first report describing a potential relationship between neuronal generators of cognitive processes, the associated electrophysiological evidence for the existence of distributed networks and BOLD fMRI signals using information from model order selection techniques.

Adult↗
PubMed2006

Direction-dependent visual cortex activation during horizontal optokinetic stimulation (fMRI study).

Looking at a moving pattern induces optokinetic nystagmus (OKN) and activates an assembly of cortical areas in the visual cortex, including lateral occipitotemporal (motion-sensitive area MT/V5) and adjacent occipitoparietal areas as well as ocular motor areas such as the prefrontal cortex, frontal, supplementary, and parietal eye fields. The aim of this functional MRI (fMRI) study was to investigate (1) whether stimulus direction-dependent effects can be found, especially in the cortical eye fields, and (2) whether there is a hemispheric dominance of ocular motor areas. In a group of 15 healthy subjects, OKN in rightward and leftward directions was visually elicited and statistically compared with the control condition (stationary target) and with each other. Direction-dependent differences were not found in the cortical eye fields, but an asymmetry of activation occurred in paramedian visual cortex areas, and there were stronger activations in the hemisphere contralateral to the slow OKN phase (pursuit). This can be explained by a shift of the mean eye position of gaze (beating field) in the direction of the fast nystagmus phases of approximately 2.6 degrees, causing asymmetrical visual cortex stimulation. The absence of a significant difference in the activation pattern of the cortical eye fields supports the view that the processing of eye movements in both horizontal directions is mediated in the same cortical ocular motor areas. Furthermore, no hemispheric dominance for OKN processing was found in right-handed volunteers.

Adult↗
PubMed2006

The striatal and extrastriatal D2/D3 receptor-binding profile of clozapine in patients with schizophrenia.

Positron emission tomography (PET) studies reveal that clozapine at clinically used doses occupies less than 60% of D2/D3 dopamine receptors in human striatum. Here, the occupancy of D2/D3 dopamine receptors by clozapine in patients with schizophrenia was determined to test the hypothesis that clozapine binds preferentially to extrastriatal dopamine receptors. A total of 15 clozapine-treated inpatients with schizophrenia underwent a [18F]fallypride PET scan. Receptor occupancy was calculated as percent reduction in binding potential relative to unblocked values measured in seven normal volunteers. Mean D2/D3 receptor occupancy was statistically significantly higher in cortical (inferior temporal cortex 55%) than in striatal regions (putamen 36%, caudate 43%, p<0.005). While the maximum attainable receptor occupancy Emax approached 100% both in the striatum and cortex, the plasma concentration at 50% of Emax (ED50) was much higher in the putamen (950 ng/ml) than in the inferior temporal cortex (333 ng/ml). Clozapine binds preferentially to cortical D2/D3 receptors over a wide range of plasma concentrations. This selectivity is lost at extremely high plasma levels. Occupancy of cortical receptors approaches 60% with plasma clozapine in the range 350-400 ng/ml, which corresponds to the threshold for antipsychotic efficacy of clozapine. Extrastriatal binding of clozapine may be more relevant to its antipsychotic actions than striatal. However, further studies with an intraindividual comparison of untreated vs treated state are desirable to confirm this finding.

Adult↗
PubMed2005

High opiate receptor binding potential in the human lateral pain system.

To determine how opiate receptor distribution is co-localized with the distribution of nociceptive areas in the human brain, eleven male healthy volunteers underwent one PET scan with the subtype-nonselective opioidergic radioligand [(18)F]fluoroethyl-diprenorphine under resting conditions. The binding potential (BP), a parameter for the regional cerebral opioid receptor availability, was computed using the occipital cortex as reference region. The following regions of interest (ROIs) were defined on individual MR images: thalamus, sensory motor strip (SI/MI area), frontal operculum, parietal operculum, anterior insular cortex, posterior insular cortex, anterior cingulate cortex (ACC; peri- and subgenual part of "classical ACC" only), midcingulate cortex (MCC, posterior part of "classical ACC"), putamen, caudate nucleus and the amygdala. BP for [(18)F]fluoroethyl-diprenorphine was lowest in the sensory motor strip (0.30). Highest BP was found in thalamus (1.36), basal ganglia (putamen 1.22, caudate 1.16) and amygdala (1.21). In the cingulate cortex, ACC (1.11) had higher BP than MCC (0.86). In the operculo-insular region, we found high BPs in all ROIs: anterior insula (1.16), posterior insula (1.05), frontal operculum (0.99) and parietal operculum (0.77). Factor analysis of interindividual variability of opiate receptor BP revealed four factors (95% explained variance): (1) operculo-insular areas, ACC, MCC and putamen, (2) amygdala and thalamus, (3) caudate and thalamus, (4) SI/MI and MCC. Nociceptive areas of the lateral pain system (frontoparietal operculum and insula) have opiate receptor BPs significantly higher than SI/MI, comparable to anterior and midcingulate areas of the medial pain system. These findings suggest that the cortical anti-nociceptive effects of opiates are not only mediated by ACC and MCC, but also by the operculo-insular cortex, if it can be assumed that opioid binding mediates anti-nociception in those structures.

Adult↗
PubMed2005

Functional implications of hippocampal volume and diffusivity in mild cognitive impairment.

Hippocampal atrophy has been related to mild cognitive impairment (MCI) and early Alzheimer disease (AD), but the diagnostic significance of cross-sectionally determined hippocampal volumes is still ambiguous. Diffusion-Tensor-Imaging (DTI) in MCI patients revealed an association of microstructural changes in hippocampal areas with verbal memory decline. MRI volumetry and DTI were combined to investigate 18 MCI patients attending a memory clinic, and 18 carefully age- and gender-matched healthy controls. Neuropsychological testing, high resolution T1-weighted volume MRI scans, and DTI scans with regions-of-interest in hippocampal areas were applied. Left hippocampal volume was significantly lower (-11%, P = 0.02) in MCI patients than in control subjects. No significant differences were found for the right hippocampus (-4%). Mean diffusivity (MD) was significantly elevated in MCI patients vs. controls in left (+10%, P = 0.002) and right hippocampal areas (+13%, P = 0.02). Hippocampal volume and MD values were not significantly correlated. Combining left hippocampal volume and MD measures showed that lower left hippocampal volumes were associated with poor verbal memory performance particularly when co-occurring with high MD values. No comparable associations could be found regarding the right hippocampal formation and with respect to non-verbal memory function. The results demonstrate that microstructural abnormalities as revealed by DTI are very sensitive early indicators of hippocampal dysfunction. The combination of macro- and microstructural parameters in hippocampal areas could be promising in early detection of neurodegenerative processes.

Aged↗
PubMed2005

Spatial resolution of fMRI in the human parasylvian cortex: comparison of somatosensory and auditory activation.

In spite of its outstanding spatial resolution, the biological resolution of functional MRI may be worse because it depends on the vascular architecture of the brain. Here, we compared the activation patterns of the secondary somatosensory and parietal ventral cortex (SII/PV) with that of the primary auditory cortex and adjacent areas (AI/AII). These two brain regions are located immediately adjacent to each other on opposite banks of the Sylvian fissure, and are anatomically and functionally distinct. In 12 healthy subjects, SII/PV was activated by pneumatic tactile stimuli applied to the index finger (0.5 cm2 contact area, 4 bar pressure), and AI/AII by amplitude-modulated tones (800 Hz carrier frequency, modulated at 24-36 Hz). Functional images were obtained with a 1.5-T scanner and were evaluated using SPM99. Sensitivity of fMRI activation in this unselected sample was 71% for tactile and 83% for auditory stimulation. Group analysis showed activation of SII/PV by tactile and activation of three locations in AI/AII by auditory stimuli. Distributions extended to the opposite side of the fissure (19-58% after tactile and 13-14% after auditory stimulation, depending on the side of stimulation/hemisphere). Morphometry of individual sulcal anatomy revealed that the course of the Sylvian fissure varied by 5.3 mm (SD) in vertical direction. Taking this into account, SII/PV was located 5.8 +/- 2.7 mm above the Sylvian fissure, whereas AI/AII was located 6.3 +/- 1.7 mm below the Sylvian fissure. Even in individual analysis, the most significant voxel after tactile stimuli in one subject was found on the "wrong" side of the fissure; this error could be ascribed to the spatial normalization procedure. These data show that fMRI signals may overlap substantially, even if the activated regions are separated by 12 mm across a major sulcus. Spatial normalization to an atlas template can introduce additional variance. Individual sulcal anatomy should be preferred over mean atlas locations.

Acoustic Stimulation↗
PubMed2005

Color-coded diffusion-tensor-imaging of posterior cingulate fiber tracts in mild cognitive impairment.

Different processes like microvascular dysfunction, free radical toxicity, beta-amyloid deposits, and Wallerian degeneration can cause functionally relevant disturbances of cerebral neuronal networks by myelin degeneration. Color-coded diffusion-tensor-imaging (ccDTI) allows the structural identification and quantification of myelinated fiber tracts. Particularly, posterior cingulate fiber tracts, which are regarded as important neuronal substrates of the network representing memory processing can be localized only imprecisely by conventional magnetic resonance imaging techniques. The posterior cingulate bundles were assessed by ccDTI in 17 patients with amnestic mild cognitive impairment (MCI), 25 patients with Alzheimer's dementia (DAT), and 21 age-matched controls. Additionally, DTI values were correlated with memory performance in the delayed verbal recall test. Fractional anisotropy and mean diffusivity differed significantly between MCI and controls, as well as between DAT and controls. Performance in the delayed verbal recall test of the entire study group correlated significantly with posterior cingulate bundle anisotropy and diffusivity. Using ccDTI seems, hence, a favorable strategy to detect and quantify the structural integrity of posterior cingulate white matter in MCI. Alterations of DTI parameters substantiate the involvement of white matter pathology in the development of MCI. Moreover, ccDTI could serve as in vivo method to investigate age and disease-related myelin alterations as potential morphological substrates of cognitive dysfunction.

Aged↗