[Learning from Errors: Qualitative Analysis of Expert Reports on Malpractice in Family Medicine]

BACKGROUND

Expert committees of the German medical associations provide a free and out-of-court evaluation of putative cases of medical malpractice. They prepare reports that contain valuable information on process steps that precede the actual treatment error. The aim of the present study was to identify and systematically categorize individual process steps in the expert reports and thus to lay the foundations for the understanding of malpractice evaluation processes.

METHODS

In this study, ten randomly selected and anonymized expert reports of the Expert Committee for Questions of Medical Liability of the District Medical Association of South Württemberg with identified GP treatment errors were evaluated, using the method of qualitative content analysis. In an iterative process, central elements of expert reports were classified into a deductively and inductively built category system.

RESULTS

Six main categories with associated subcategories were identified: 1) structural aspects of the report, 2) doctor-patient communication, 3) medical course, 4) patient's experience, 5) action by the GP team, and 6) coordinative role in the health care system. The category system showed sufficient reliability with repeated use.

CONCLUSION

This study offers an opportunity to learn from errors. The proposed system allows to structure the complexity of expert reports on GP malpractice and may thus serve as a tool in various contexts. In particular, it facilitates the preparation and comparative analysis of reports in a structured way. It could also be used in health care research as well as in education and training.

Atypical language organization following perinatal infarctions of the left hemisphere is associated with structural changes in right-hemispheric grey matter

AIM

To assess how atypical language organization after early left-hemispheric brain lesions affects grey matter in the contralesional hemisphere.

METHOD

This was a cross-sectional study with between-group comparisons of 14 patients (six female, 8-26 years) with perinatal left-hemispheric brain lesions (two arterial ischemic strokes, 11 periventricular haemorrhagic infarctions, one without classification) and 14 typically developing age-matched controls (TDC) with functional magnetic resonance imaging (fMRI) documented left-hemispheric language organization (six female, 8-28 years). MRI data were analysed with SPM12, CAT12, and custom scripts. Language lateralization indices were determined by fMRI within a prefrontal mask and right-hemispheric grey matter group differences by voxel-based morphometry (VBM).

RESULTS

FMRI revealed left-dominance in seven patients with typical language organization (TYP) and right-dominance in seven patients with atypical language organization (ATYP) of 14 patients. VBM analysis of all patients versus controls showed grey matter reductions in the middle temporal gyrus of patients. A comparison between the two patient subgroups revealed an increase of grey matter in the middle frontal gyrus in the ATYP group. Voxel-based regression analysis confirmed that grey matter increases in the middle frontal gyrus were correlated with atypical language organization.

INTERPRETATION

Compatible with a non-specific lesion effect, we found areas of grey matter reduction in patients as compared to TDC. The grey matter increase in the middle frontal gyrus seems to reflect a specific compensatory effect in patients with atypical language organization.

WHAT THIS PAPER ADDS

Perinatal stroke leads to decreased grey matter in the contralesional hemisphere. Atypical language organization is associated with grey matter increases in contralesional language areas.

Reduced structural connectivity in non-motor networks in children born preterm and the influence of early postnatal human cytomegalovirus infection

Introduction

Preterm birth is increasingly recognized to cause lifelong functional deficits, which often show no correlate in conventional MRI. In addition, early postnatal infection with human cytomegalovirus (hCMV) is being discussed as a possible cause for further impairments. In the present work, we used fixel-based analysis of diffusion-weighted MRI to assess long-term white matter alterations associated with preterm birth and/or early postnatal hCMV infection.

Materials and methods

36 former preterms (PT, median age 14.8 years, median gestational age 28 weeks) and 18 healthy term-born controls (HC, median age 11.1 years) underwent high angular resolution DWI scans (1.5 T, b = 2 000 s/mm2, 60 directions) as well as clinical assessment. All subjects showed normal conventional MRI and normal motor function. Early postnatal hCMV infection status (CMV+ and CMV-) had been determined from repeated screening, ruling out congenital infections. Whole-brain analysis was performed, yielding fixel-wise metrics for fiber density (FD), fiber cross-section (FC), and fiber density and cross-section (FDC). Group differences were identified in a whole-brain analysis, followed by an analysis of tract-averaged metrics within a priori selected tracts associated with cognitive function. Both analyses were repeated while differentiating for postnatal hCMV infection status.

Results

PT showed significant reductions of fixel metrics bilaterally in the cingulum, the genu corporis callosum and forceps minor, the capsula externa, and cerebellar and pontine structures. After including intracranial volume as a covariate, reductions remained significant in the cingulum. The tract-specific investigation revealed further reductions bilaterally in the superior longitudinal fasciculus and the uncinate fasciculus. When differentiating for hCMV infection status, no significant differences were found between CMV+ and CMV-. However, comparing CMV+ against HC, fixel metric reductions were of higher magnitude and of larger spatial extent than in CMV- against HC.

Conclusion

Preterm birth can lead to long-lasting alterations of WM micro- and macrostructure, not visible on conventional MRI. Alterations are located predominantly in WM structures associated with cognitive function, likely underlying the cognitive deficits observed in our cohort. These observed structural alterations were more pronounced in preterms who suffered from early postnatal hCMV infection, in line with previous studies suggesting an additive effect.

Clinical significance of diffusion tensor imaging in metachromatic leukodystrophy

BACKGROUND AND PURPOSE

Metachromatic leukodystrophy (MLD) is a lysosomal enzyme deficiency disorder leading to progressive demyelination and, consecutively, to cognitive and motor decline. Brain MRI can detect affected white matter as T2 hyperintense but cannot quantify the gradual microstructural process of demyelination more accurately. Our study aimed to investigate the value of routine MR diffusion tensor imaging in assessing disease progression.

MATERIALS AND METHODS

MR diffusion parameters (ADC and FA) were in the frontal white matter (FWM), central region (CR) and posterior limb of the internal capsule (PLIC) in 111 MR data sets from a natural history study of 83 patients (age 0.5-39.9 years; 35 late-infantile, 45 juvenile, 3 adult, with clinical diffusion sequences of different scanner manufacturers) as well as 120 controls. Results were correlated with clinical parameters reflecting motor and cognitive function.

RESULTS

ADC values increase and FA values decrease depending on disease stage/severity. They show region-specific correlations with clinical parameters of motor and cognitive symptoms, respectively. Higher ADC levels in CR at diagnosis predicted a disease course with more rapid motor deterioration in juvenile MLD patients. In highly-organised tissue like the corticospinal tract in particular, diffusion MR parameters were highly sensitive to MLD associated changes and did not correlate with the visual quantification of T2 hyperintensities.

CONCLUSION

Our results show that diffusion MRI can deliver valuable, robust, clinically meaningful and easily obtainable/accessible/available parameters in the assessment of prognosis and progression of metachromatic leukodystrophy. Therefore, it provides additional quantifiable information to established methods such as T2 hyperintensity.

Disease progression of heart failure in type 2 diabetes patients in Germany; a real world data analysis using health insurance claims data

 

Individuals with Type 2 Diabetes (T2D) show two- to four-fold increased risk of Heart failure (HF). Given the increasing T2D prevalence in Germany, researching the interaction of T2DM and HF is of high importance. HF still progresses rapidly. Left ventricular ejection fraction (LVEF) plays an important role in understanding disease progression. Commonly, LVEF is being distinguished into three categories: HF with preserved LVEF (HFpEF), HF with moderate reduced LVEF (HFmEF) and HF with reduced LVEF (HFrEF). In Germany there are no recent data on disease progression in HF especially according to LVEF categories. Purpose of this study is to a) measure how many T2DM patients acquire HF over two years; b) understand the progression of HF in these patients in a five-year follow-up; and c) visualize disease progression with Sankey plots.

We used insurance claims data from German Statutory Health Insurances (SHI). As LVEF category is not included in these data, a model was used to classify patients into HFrEF or HFpEF (with omitting the HFmEF category due to better statistical performance of a binary model). The model was derived from a set of 34 proxy variables (disease coding, interventions, drug prescriptions). Selection period for T2D patients is 2013. Inclusion period was 2014–2015, follow-up 2016–2020. Baseline characteristics include demographic data, disease stage, comorbidities, and risk factors. Follow-up criteria were MACE (including hospital admission) changes in LVEF category and mortality. 173,195 individuals with T2D were identified in 2013, median age 66 yrs. 6,725 (3.88% of the overall sample) developed HF in 2014 or 2015, median age 74 yrs. As Sankey plot visualizations show, 34.4% of the patients had MACE over the course of five years; 24.5% were still alive and 9.9% died from CV-death. Further 33% died of other causes. Myocardial infarct was the most common MACE, followed by stroke (32%), hospital admission for HF (28%) and CV death (7%). 40% of patients were never admitted to a hospital over the study period. Exploratory analyses identified 5,282 HFpEF patients (78.54%) and 1,443 HFrEF patients (21.46%). Survival after 5 years in HFpEF patients was 71%, in HFrEF patients 29%. After five years 3,430 (90%) surviving patients were still in HFpEF and 399 (10%) in HFrEF.

This analysis provides disease progression insights in T2D patients who developed HF in Germany. The sample is representative for the country and numbers can be extrapolated to the overall German SHI population. A significant number of patients die within 5 years of initial diagnosis. As echo diagrams are not available in German insurance claims, validity of the predicted LVEF cannot be assessed. Further research featuring real world LVEF score validation would be highly desirable. Beyond therapeutic care, digital solutions for closer monitoring of these patients may improve the outcome of these patients.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Sanofi

MRI-based brain volumes of preterm infants at term: a systematic review and meta-analysis

BACKGROUND

MRI allows a detailed assessment of brain structures in preterm infants, outperforming cranial ultrasound. Neonatal MR-based brain volumes of preterm infants could serve as objective, quantitative and reproducible surrogate parameters of early brain development. To date, there are no reference values for preterm infants' brain volumes at term-equivalent age.

OBJECTIVE

Systematic review of the literature to determine reference ranges for MRI-based brain volumes of very preterm infants at term-equivalent age.

METHODS

PubMed Database was searched on 6 April 2020 for studies reporting MR-based brain volumes on representative unselected populations of very preterm and/or very low birthweight infants examined at term equivalent age (defined as 37-42 weeks mean postmenstrual age at MRI). Analyses were limited to volumetric parameters reported in >3 studies. Weighted mean volumes and SD were both calculated and simulated for each parameter.

RESULTS

An initial 367 publications were identified. Following application of exclusion criteria, 13 studies from eight countries were included for analysis, yielding four parameters. Weighted mean total brain volume was 379 mL (SD 72 mL; based on n=756). Cerebellar volume was 21 mL (6 mL; n=791), cortical grey matter volume 140 mL (47 mL; n=572) and weighted mean volume of unmyelinated white matter was 195 mL (38 mL; n=499).

CONCLUSION

This meta-analysis reports pooled data on several brain and cerebellar volumes which can serve as reference for future studies assessing MR-based volumetric parameters as a surrogate outcome for neurodevelopment and for the interpretation of individual or cohort MRI-based volumetric findings.

Cognitive development after perinatal unilateral infarctions: No evidence for preferential sparing of verbal functions

BACKGROUND

Even children with extensive perinatal left-sided lesions have been reported to show normal language functions based on right-hemispheric language reorganization. This reorganization can lead to deficits in originary right hemispheric functions ("crowding hypothesis"). In a previous study, however, we identified epilepsy (even when well-controlled), and not language reorganization, as the major risk factor for impaired nonverbal functions. Here, we asked whether verbal and nonverbal functions develop differently, and whether they share the same risk factors.

METHODS

We investigated 23 patients (11f, Md = 12.56 years) with perinatal strokes (16 left-sided, 8 with epilepsy), and 23 healthy age-matched controls (8 f, Md = 12.42years). Language functions were assessed using the Potsdam Illinois Test of Psycholinguistic Abilities, nonverbal intelligence with the Test of Nonverbal Intelligence, language lateralization with functional MRI, and lesion size with MRI-based volumetry.

RESULTS

We found no systematic difference between verbal and nonverbal skills in our patients or controls [median difference Z(PITPA)-Z(TONI): patients = -0.03, controls = -0.06]. Accordingly, verbal and nonverbal functions were strongly correlated in patients (r = 0.80) and in controls (r = 0.74). Language ability correlated significantly with epilepsy. Furthermore, in patients with epilepsies, verbal skills were significantly lower than in controls.

CONCLUSION

In our cohort, we found no evidence for a differential effect of perinatal strokes on the development of verbal versus nonverbal functions, and, specifically, no evidence for a preferential sparing of verbal functions. Epilepsy, even when well-controlled, was confirmed as a single key risk factor for verbal functions.

Bone conducted vibration is an effective stimulus for otolith testing in cochlear implant patients

BACKGROUND

Treatment with a cochlear implant (CI) poses the risk of inducing a behaviorally unmeasurable air-bone gap leading to false negative absence of cervical and ocular vestibular evoked myogenic potentials (cVEMPs, oVEMPs) to air conducted sound (ACS).

OBJECTIVE

To investigate VEMP response rates to ACS and bone conducted vibration (BCV) in CI patients and the applicability of the B81 transducer for BCV stimulation.

METHODS

Prospective experimental study including unilateral CI patients, measuring cVEMPs and oVEMPs to ACS and to BCV, comparing response rates, signed asymmetry ratios, latencies, and amplitudes.

RESULTS

Data of 13 CI patients (mean age 44±12 years) were analyzed. For the CI side, oVEMP and cVEMP response rates were significantly higher for BCV (77%cVEMP, 62%oVEMP) compared to ACS (23%cVEMP, 8%oVEMP). For the contralateral side, no difference between response rates to ACS (85%cVEMP, 69%oVEMP) and BCV (85%cVEMP, 77%oVEMP) was observed. Substantially higher asymmetries were observed for ACS (-88±23%for cVEMPs, -96±11%for oVEMPs) compared to BCV (-12±45%for cVEMPs, 4±74%for oVEMPs).

CONCLUSIONS

BCV is an effective stimulus for VEMP testing in CI patients. The B81 is a feasible stimulator.

A hydrothermal apparatus for x-ray absorption spectroscopy of hydrothermal fluids at DESY

We present a new autoclave that enables in situ characterization of hydrothermal fluids at high pressures and high temperatures at synchrotron x-ray radiation sources. The autoclave has been specifically designed to enable x-ray absorption spectroscopy in fluids with applications to mineral solubility and element speciation analysis in hydrothermal fluids in complex compositions. However, other applications, such as Raman spectroscopy, in high-pressure fluids are also possible with the autoclave. First experiments were run at pressures between 100 and 600 bars and at temperatures between 25 °C and 550 °C, and preliminary results on scheelite dissolution in fluids of different compositions show that the autoclave is well suited to study the behavior of ore-forming metals at P-T conditions relevant to the Earth's crust.

Novel experimental setup for megahertz X-ray diffraction in a diamond anvil cell at the High Energy Density (HED) instrument of the European X-ray Free-Electron Laser (EuXFEL)

The high-precision X-ray diffraction setup for work with diamond anvil cells (DACs) in interaction chamber 2 (IC2) of the High Energy Density instrument of the European X-ray Free-Electron Laser is described. This includes beamline optics, sample positioning and detector systems located in the multipurpose vacuum chamber. Concepts for pump-probe X-ray diffraction experiments in the DAC are described and their implementation demonstrated during the First User Community Assisted Commissioning experiment. X-ray heating and diffraction of Bi under pressure, obtained using 20 fs X-ray pulses at 17.8 keV and 2.2 MHz repetition, is illustrated through splitting of diffraction peaks, and interpreted employing finite element modeling of the sample chamber in the DAC.

Increased Brain Age Gap Estimate (BrainAGE) in Young Adults After Premature Birth

Recent evidence suggests increased metabolic and physiologic aging rates in premature-born adults. While the lasting consequences of premature birth on human brain development are known, its impact on brain aging remains unclear. We addressed the question of whether premature birth impacts brain age gap estimates (BrainAGE) using an accurate and robust machine-learning framework based on structural MRI in a large cohort of young premature-born adults (n = 101) and full-term (FT) controls (n = 111). Study participants are part of a geographically defined population study of premature-born individuals, which have been followed longitudinally from birth until young adulthood. We investigated the association between BrainAGE scores and perinatal variables as well as with outcomes of physical (total intracranial volume, TIV) and cognitive development (full-scale IQ, FS-IQ). We found increased BrainAGE in premature-born adults [median (interquartile range) = 1.4 (-1.3-4.7 years)] compared to full-term controls (p = 0.002, Cohen's d = 0.443), which was associated with low Gestational age (GA), low birth weight (BW), and increased neonatal treatment intensity but not with TIV or FS-IQ. In conclusion, results demonstrate elevated BrainAGE in premature-born adults, suggesting an increased risk for accelerated brain aging in human prematurity.

Non-verbal Intelligence in Unilateral Perinatal Stroke Patients With and Without Epilepsies

Background: The risk factors for impaired cognitive development after unilateral perinatal stroke are poorly understood. Non-verbal intelligence seems to be at particular risk, since language can shift to the right hemisphere and may thereby reduce the capacity of the right hemisphere for its originary functions. Pharmaco-refractory epilepsies, a frequent complication of perinatal strokes, often lead to impaired intelligence. Yet, the role of well-controlled epilepsies is less well-understood. Here, we investigated whether well-controlled epilepsies, motor impairment, lesion size, lesion side, and lateralization of language functions influence non-verbal functions. Methods: We recruited 8 patients with well-controlled epilepsies (9-26 years), 15 patients without epilepsies (8-23 years), and 23 healthy controls (8-27 years). All underwent the Test of Non-verbal Intelligence, a motor-independent test, which excludes biased results due to motor impairment. Language lateralization was determined with functional MRI, lesion size with MRI-based volumetry, and hand motor impairment with the Jebson-Taylor Hand Function-Test. Results: Patients with epilepsies showed significantly impaired non-verbal intelligence [Md = 89.5, interquartile range (IQR) = 13.5] compared with controls (Md = 103, IQR = 17). In contrast, patients without epilepsies (Md = 97, IQR = 15.0) performed within the range of typically developing children. A multiple regression analysis revealed only epilepsy as a significant risk factor for impaired non-verbal functions. Conclusion: In patients with unilateral perinatal strokes without epilepsies, the neuroplastic potential of one healthy hemisphere is able to support the development of normal non-verbal cognitive abilities, regardless of lesion size, lesion side, or language lateralization. In contrast, epilepsy substantially reduces this neuroplastic potential; even seizure-free patients exhibit below-average non-verbal cognitive functions.

A multidimensional artefact-reduction approach to increase robustness of first-level fMRI analyses: Censoring vs. interpolating

BACKGROUND

This manuscript describes a new, multidimensional and data-driven approach to identify outlying datapoints from a first-level fMRI dataset.

NEW METHOD

Using three different indicators of data corruption (the fast variance component of DVARS [Δ%D-var], scan-to-scan total displacement [STS], and each scan's overall explained variance [R²]), it identifies outlying datapoints while being balanced using Akaike'c corrected criterion (AIC _C) to avoid overcorrection. We then explore the impact of censoring, interpolating, or both, to remove a bad scan's contribution to the final timeseries.

RESULTS AND COMPARISON WITH EXISTING METHODS

Our results (using three real-life datasets and extensive simulations) show that motion-corrupted datapoints as well as non-motion related image artefacts are detected reliably. Using several indicators is shown to be an advantage over existing single-indicator solutions in different settings. As a result of using our algorithm, stronger activation (as detected by both T-value and number of activated voxels) and an increase in the temporal signal-to-noise ratio can be seen. The effects of censoring and interpolation are distinct and complex.

CONCLUSIONS

The multidimensional approach described here is able to identify outlying datapoints in fMRI timeseries, with demonstrable positive effects on several outcome measures. While censoring datapoints may be preferable in many settings, the ultimate choice on which approach to choose may depend on the data at hand. Recommendations are provided for different scenarios.

Physical and ecological effects of rehabilitating the geothermally influenced Waikite Wetland, New Zealand

Pressure to optimise land use and to maximise the economic viability of land has had a detrimental impact on wetlands worldwide. Rehabilitating wetlands has been identified by resource managers as increasingly important to enhance environmental values and restore ecosystem functions that may have been lost through developments effecting wetlands. This paper investigates rehabilitating a geothermally influenced wetland that had been drained and used for grazing stock. The Waikite Wetland (New Zealand) is a relatively unique wetland because the primary water source to the wetland has a significant geothermal water component. This results in the area hosting populations of rare flora and fauna that are significant to New Zealand. A range of management actions that included diverting a geothermal stream back into the wetland, blocking drains, pest control, weed control, native plantings, fencing and building a weir to increase water levels were used to rehabilitate the wetland. This was done to promote thermotolerant vegetation growth, restore wetland water levels and minimise pest plant species re-establishing while minimising the effects on geothermal surface features and allowing indigenous wetland vegetation to re-establish. Physical, chemical and vegetation monitoring show that management actions have increased thermotolerant vegetation growth in the wetland while having a small potential impact on geothermal discharges into the wetland. Increasing the water level in the wetland appears to be helping control plant pest species close to the weir, but has also made sensitive vegetation growing close to the waterways more susceptible to flooding caused by high-intensity rainfall events.

Clinical application of advanced MR methods in children: points to consider

The application of both functional MRI and diffusion MR tractography prior to a neurosurgical operation is well established in adults, but less so in children, for several reasons. For this review, we have identified several aspects (task design, subject preparation, actual scanning session, data processing, interpretation of results, and decision-making) where pediatric peculiarities should be taken into account. Further, we not only systematically identify common issues, but also provide solutions, based on our experience as well as a review of the pertinent literature. The aim is to provide the clinician as well as the imaging scientist with information that helps to plan, conduct, and interpret such a clinically-indicated exam in a way that maximizes benefit for, and minimizes the burden on the individual child.

Regional Gray Matter Volume Differences Between Adolescents With ADHD and Typically Developing Controls: Further Evidence for Anterior Cingulate Involvement

OBJECTIVE

The present study investigated structural brain differences between adolescents with ADHD and matched control participants.

METHOD

Voxel-based morphometry (VBM) using the DARTEL approach was performed to assess regional gray matter (GM) volumes. Additionally, individual performance on tests of attention was recorded to correlate ADHD related cognitive impairments with regional gray matter abnormalities.

RESULTS

We found significantly smaller GM volume in subjects with ADHD compared to their matched controls within the anterior cingulate cortex (ACC), the occipital cortex, bilateral hippocampus/amygdala and in widespread cerebellar regions. Further, reductions of the ACC gray matter volume were found to correlate with scores of selective inattention.

CONCLUSION

These findings underline that structural alterations in a widespread cortico-subcortical network seem to underlie the observable attention problems in patients with ADHD.

A spline-based regression parameter set for creating customized DARTEL MRI brain templates from infancy to old age

This dataset contains the regression parameters derived by analyzing segmented brain MRI images (gray matter and white matter) from a large population of healthy subjects, using a multivariate adaptive regression splines approach. A total of 1919 MRI datasets ranging in age from 1–75 years from four publicly available datasets (NIH, C-MIND, fCONN, and IXI) were segmented using the CAT12 segmentation framework, writing out gray matter and white matter images normalized using an affine-only spatial normalization approach. These images were then subjected to a six-step DARTEL procedure, employing an iterative non-linear registration approach and yielding increasingly crisp intermediate images. The resulting six datasets per tissue class were then analyzed using multivariate adaptive regression splines, using the CerebroMatic toolbox. This approach allows for flexibly modelling smoothly varying trajectories while taking into account demographic (age, gender) as well as technical (field strength, data quality) predictors. The resulting regression parameters described here can be used to generate matched DARTEL or SHOOT templates for a given population under study, from infancy to old age. The dataset and the algorithm used to generate it are publicly available at https://irc.cchmc.org/software/cerebromatic.php.

Lesion characteristics driving right-hemispheric language reorganization in congenital left-hemispheric brain damage

Pre- or perinatally acquired ("congenital") left-hemispheric brain lesions can be compensated for by reorganizing language into homotopic brain regions in the right hemisphere. Language comprehension may be hemispherically dissociated from language production. We investigated the lesion characteristics driving inter-hemispheric reorganization of language comprehension and language production in 19 patients (7-32years; eight females) with congenital left-hemispheric brain lesions (periventricular lesions [n=11] and middle cerebral artery infarctions [n=8]) by fMRI. 16/17 patients demonstrated reorganized language production, while 7/19 patients had reorganized language comprehension. Lesions to the insular cortex and the temporo-parietal junction (predominantly supramarginal gyrus) were significantly more common in patients in whom both, language production and comprehension were reorganized. These areas belong to the dorsal stream of the language network, participating in the auditory-motor integration of language. Our data suggest that the integrity of this stream might be crucial for a normal left-lateralized language development.

Demyelination load as predictor for disease progression in juvenile metachromatic leukodystrophy

Objective

The aim of this study was to investigate whether the extent and topography of cerebral demyelination correlates with and predicts disease progression in patients with juvenile metachromatic leukodystrophy (MLD).

Methods

A total of 137 MRIs of 46 patients with juvenile MLD were analyzed. Demyelination load and brain volume were quantified using the previously developed Software “clusterize.” Clinical data were collected within the German Leukodystrophy Network and included full scale intelligence quotient (FSIQ) and gross motor function data. Voxel‐based lesion‐symptom mapping (VLSM) across the whole brain was performed to investigate the spatial relationship of cerebral demyelination with motor or cognitive function. The prognostic value of the demyelination load at disease onset was assessed to determine the severity of disease progression.

Results

The demyelination load (corrected by the individual brain volume) correlated significantly with gross motor function (r = +0.55) and FSIQ (r = −0.55). Demyelination load at disease onset was associated with the severity of disease progression later on (P < 0.01). VLSM results associated frontal lobe demyelination with loss in FSIQ and more central region demyelination with decline of motor function. Especially progression of demyelination within the motor area was associated with severe disease progression.

Interpretation

We were able to show for the first time in a large cohort of patients with juvenile MLD that the demyelination load correlates with motor and cognitive symptoms. Moreover, demyelination load at disease onset, especially the involvement of the central region, predicts severity of disease progression. Thus, demyelination load seems a functionally relevant MRI parameter.

Plasticity during Early Brain Development Is Determined by Ontogenetic Potential

Two competing hypotheses address neuroplasticity during early brain development: the "Kennard principle" describes the compensatory capacities of the immature developing CNS as superior to those of the adult brain, whereas the "Hebb principle" argues that the young brain is especially sensitive to insults. We provide evidence that these principles are not mutually exclusive. Following early brain lesions that are unilateral, the brain can refer to homotopic areas of the healthy hemisphere. This potential for reorganization is unique to the young brain but available only when, during ontogenesis of brain development, these areas have been used for the functions addressed. With respect to motor function, ipsilateral motor tracts can be recruited, which are only available during early brain development. Language can be reorganized to the right after early left hemispheric lesions, as the representation of the language network is initially bilateral. However, even in these situations, compensatory capacities of the developing brain are found to have limitations, probably defined by early determinants. Thus, plasticity and adaptivity are seen only within ontogenetic potential; that is, axonal or cortical structures cannot be recruited beyond early developmental possibilities. The young brain is probably more sensitive and vulnerable to lesions when these are bilateral. This is shown here for bilateral periventricular white matter lesions that clearly have an impact on cortical architecture and function, thus probably interfering with early network building.

CerebroMatic: A Versatile Toolbox for Spline-Based MRI Template Creation

Brain image spatial normalization and tissue segmentation rely on prior tissue probability maps. Appropriately selecting these tissue maps becomes particularly important when investigating "unusual" populations, such as young children or elderly subjects. When creating such priors, the disadvantage of applying more deformation must be weighed against the benefit of achieving a crisper image. We have previously suggested that statistically modeling demographic variables, instead of simply averaging images, is advantageous. Both aspects (more vs. less deformation and modeling vs. averaging) were explored here. We used imaging data from 1914 subjects, aged 13 months to 75 years, and employed multivariate adaptive regression splines to model the effects of age, field strength, gender, and data quality. Within the spm/cat12 framework, we compared an affine-only with a low- and a high-dimensional warping approach. As expected, more deformation on the individual level results in lower group dissimilarity. Consequently, effects of age in particular are less apparent in the resulting tissue maps when using a more extensive deformation scheme. Using statistically-described parameters, high-quality tissue probability maps could be generated for the whole age range; they are consistently closer to a gold standard than conventionally-generated priors based on 25, 50, or 100 subjects. Distinct effects of field strength, gender, and data quality were seen. We conclude that an extensive matching for generating tissue priors may model much of the variability inherent in the dataset which is then not contained in the resulting priors. Further, the statistical description of relevant parameters (using regression splines) allows for the generation of high-quality tissue probability maps while controlling for known confounds. The resulting CerebroMatic toolbox is available for download at http://irc.cchmc.org/software/cerebromatic.php.

Multimodal Assessment Reveals Late-Onset Hemispheric Shift of Language in a Child with Meningocerebral Dysplasia

We report on a girl with progressive left frontal tissue destruction starting at the age of almost 8 years. She manifested acutely with epileptic seizures accompanied by Broca aphasia as well as transient right hemiparesis. Due to refractory epilepsy developing over the next years, which originated from the left frontal lobe, the decision was made to proceed to epilepsy surgery. By then, her language functions had recovered despite progressive left frontal tissue-destruction, raising the possibility of a hemispheric shift of language. Clinical functional magnetic resonance imaging (fMRI) was conducted to localize brain regions involved in language production. A complex pattern of clear right-hemispheric dominance, but with some left-sided contribution was found. However, a Wada test suggested the left hemisphere to be critical, seemingly contradicting fMRI. Invasive electroencephalogram recordings could reconcile these results by identifying the fMRI-detected, residual left-sided activation as being relevant for speech production. Only by combining the localizing information from fMRI with the information obtained by two invasive procedures could the unusual pattern of late-onset language reorganization be uncovered. This allowed for extensive left frontal resection, with histology confirming meningocerebral angiodysplasia. Postoperatively, language functions were preserved and seizure outcome was excellent. The implications of our findings for presurgical assessments in children are discussed.

MR diffusion imaging and 1H spectroscopy in a child with medulloblastoma: A case report

We report on a child with a metastasising medulloblastoma which was assessed by MR diffusion imaging and 1H MR spectroscopy (MRS). Reduced mean apparent diffusion coefficients and a high amount of taurine could be demonstrated. This is the first reported case of high taurine in medulloblastoma in vivo and confirms earlier in vitro findings. It is suggested that the changes on diffusion imaging, possibly reflecting the small-cell histology of the tumour and high taurine in MRS, are indicative of medulloblastoma.

[Endoscopic mucosal resection (EMR) followed by radiofrequency ablation (RFA) in neoplastic Barrett's esophagus or Barrett early cancer is also economically superior to sole radical endoscopic resection]

INTRODUCTION

Neoplastic changes (mild or high grade intraepithelial neoplasia (L- or HGIEN) or early cancer) in Barrett esophagus are treated with various methods. This study compares clinical-economical aspects of sole stepwise radical endoscopic resection (SRER) against combination treatment with EMR (Endoscopic mucosal resection) and RFA (radiofrequency ablation).

MATERIAL AND METHODS

Based on clinical data from a randomized controlled trial 1 we developed an economic model for costs of treatment according to the German Hospital Remuneration System (G-DRG). Our calculating incorporated initial treatment costs and the cost of treating complications (both paid via G-DRG).

RESULTS

Medical and economically, the treatment with EMR + RFA advantages over sole SRER treatment 1. The successful complete resection or destruction of neoplastic intestinal metaplastic tissue is similar in both procedures. Acute complications (24 vs. 13 % in SRER EMR + RFA) and late complications (88 vs. 13 % in SRER EMR + RFA) are significantly more likely in sole SRER than in the EMR + RFA.

DISCUSSION

While SRER initially appears more cost-effective as a sole therapy, cost levels move significantly above EMR+RFA due to higher complication rates and following procedures costs. Overall, the costs of treatment was € 13 272.11 in the SRER group and € 11 389.33 in the EMR + RFA group. The EMR + RFA group thus achieved a cost advantage of € 1882.78. The study shows that the treatment of neoplastic Barrett esophagus with EMR + RFA is also appropriate in economic terms.

Exploration of the phase diagram of liquid water in the low-temperature metastable region using synthetic fluid inclusions

The paper presents experimental data of the low-temperature metastable region of liquid water to evaluate and improve theoretical models describing the p–V–T properties of water.

Age-dependent mesial temporal lobe lateralization in language fMRI

OBJECTIVE

Functional magnetic resonance imaging (fMRI) activation of the mesial temporal lobe (MTL) may be important for epilepsy surgical planning. We examined MTL activation and lateralization during language fMRI in children and adults with focal epilepsy.

METHODS

One hundred forty-two controls and patients with left hemisphere focal epilepsy (pediatric: epilepsy, n = 17, mean age = 9.9 ± 2.0; controls, n = 48; mean age = 9.1 ± 2.6; adult: epilepsy, n = 20, mean age = 26.7 ± 5.8; controls, n = 57, mean age = 26.2 ± 7.5) underwent 3T fMRI using a language task (auditory description decision task). Image processing and analyses were conducted using Statistical Parametric Mapping (SPM8); regions of interest (ROIs) included MTL, Broca's area, and Wernicke's area. We assessed group and individual MTL activation, and examined degree of lateralization.

RESULTS

Patients and controls (pediatric and adult) demonstrated group and individual MTL activation during language fMRI. MTL activation was left lateralized for adults, but less so in children (p's < 0.005). Patients did not differ from controls in either age group. Stronger left-lateralized MTL activation was related to older age (p = 0.02). Language lateralization (Broca's and Wernicke's) predicted 19% of the variance in MTL lateralization for adults (p = 0.001), but for not children.

SIGNIFICANCE

Language fMRI may be used to elicit group and individual MTL activation. The developmental difference in MTL lateralization and its association with language lateralization suggests a developmental shift in lateralization of MTL function, with increased left lateralization across the age span. This shift may help explain why children have better memory outcomes following resection compared to adults.

A "one size fits all" approach to language fMRI: increasing specificity and applicability by adding a self-paced component

We have previously established an fMRI task battery suitable for mapping the language processing network in children. Among the tasks used, the synonyms and the vowel identification task induced robust task-related activations in children with average language abilities; however, the fixed presentation time seems to be a drawback in participants with above- or below-average language abilities. This feasibility study in healthy adults (n = 20) was aimed at adapting these tasks to the individual level of each patient by implementing a self-paced stimulus presentation. The impact of using a block- versus an event-related statistical approach was also evaluated. The self-paced modification allowed our participants with above-average language abilities to process stimuli much faster than originally implemented, likely increasing task adherence. A higher specificity of the event-related analysis was confirmed by stronger left inferior frontal and crossed cerebellar activations. We suggest that self-paced paradigms and event-related analyses may both increase specificity and applicability.

A rabbit humerus model of plating and nailing osteosynthesis with and without Staphylococcus aureus osteomyelitis

The local mechanical environment at a fracture is known to influence biological factors such as callus formation, immune cell recruitment and susceptibility to infection. Infection models incorporating a fracture are therefore required to evaluate prevention and treatment of infection after osteosynthesis. The aim of this study was to create humane, standardised and repeatable preclinical models of implant-related bone infection after osteosynthesis in the rabbit humerus. Custom-designed interlocked intramedullary nails and commercially available locking plates were subjected to biomechanical evaluation in cadaveric rabbit humeri; a 10-week in vivo healing study; a dose response study with Staphylococcus aureus over 4 weeks; and finally, a long-term infection of 10 weeks in the plate model.Outcome measures included biomechanical testing, radiography, histology, haematology and quantitative bacteriology. Both implants offered similar biomechanical stability in cadaveric bones, and when applied in the in vivo study, resulted in complete radiographic and histological healing and osteotomy closure within 10-weeks. As expected in the infection study, higher bacterial doses led to an increasing infection rate. In both infected groups, there was a complete lack of osteotomy closure at 4 weeks. C-reactive protein (CRP), lymphocyte: granulocyte ratio and weight loss were increased in infected animals receiving IM nails in comparison with non-inoculated equivalents, although this was less evident in the plate group. In the 10-week infection group, healing does not occur in the plated rabbits. We have successfully developed a rabbit model that is suitable for further studies, particularly those looking into preventative strategies for post-traumatic implant-related osteomyelitis.

Using fMRI to Investigate Memory in Young Children Born Small for Gestational Age

Objectives

Intrauterine growth restriction (IUGR) can lead to infants being born small for gestational age (SGA). SGA is associated with differences in brain anatomy and impaired cognition. We investigated learning and memory in children born SGA using neuropsychological testing and functional Magnetic Resonance Imaging (fMRI).

Study Design

18 children born appropriate for gestational age (AGA) and 34 SGA born children (18 with and 16 without postnatal catch-up growth) participated in this study. All children were between 4 and 7 years old. Cognitive functioning was assessed by IQ and memory testing (Digit/Word Span and Location Learning). A newly developed fMRI picture encoding task was completed by all children in order to assess brain regions involved in memory processes.

Results

Neuropsychological testing demonstrated that SGA children had IQ’s within the normal range but lower than in AGA and poorer performances across measures of memory. Using fMRI, we observed memory related activity in posterior parahippocampal gyrus as well as the hippocampus proper. Additionally, activation was seen bilaterally in the prefrontal gyrus. Children born SGA showed less activation in the left parahippocampal region compared to AGA.

Conclusions

This is the first fMRI study demonstrating different brain activation patterns in 4-7 year old children born SGA, suggesting that intrauterine growth restriction continues to affect neural functioning in children later-on.

Postnatal human cytomegalovirus infection in preterm infants has long-term neuropsychological sequelae

OBJECTIVE

To evaluate whether an early postnatal infection poses a long-term risk for neuropsychological impairment to neonates born very prematurely.

STUDY DESIGN

Adolescents born very preterm (n = 42, 11.6-16.2 years, mean = 13.9; 15 girls; 19 with and 23 without an early postnatal human cytomegalovirus [CMV] infection) and typically developing, term born controls (n = 24, 11.3-16.6 years, mean = 13.6; 12 girls) were neuropsychologically assessed with the German version of the Wechsler Intelligence Scale and the Developmental Test for Visual Perception.

RESULTS

As expected, the full cohort of adolescents born preterm had significantly lower scores than term born controls on IQ (preterm: mean [SD] = 98.43 [14.83], control: 110.00 [8.10], P = .015) and on visuoperceptive abilities (95.64 [12.87] vs 106.24 [9.95], P = .016). Furthermore, adolescents born preterm with early postnatal CMV infection scored significantly lower than those without this infection regarding overall cognitive abilities (92.67 [14.71] vs 102.75 [13.67], P = .030), but not visuoperceptive abilities (91.22 [10.88] vs 98.96 [13.45], P > .05).

CONCLUSIONS

In our small but well-characterized group, our results provide evidence for adverse effects of early postnatal CMV infection on overall cognitive functions in adolescents born preterm. If confirmed, these results support the implementation of preventive measures.

Comparison of different tractography algorithms and validation by intraoperative stimulation in a child with a brain tumor

BACKGROUND

Advanced modalities such as functional magnetic resonance imaging (MRI) and diffusion MR tractography offer in vivo information about brain networks and are therefore increasingly used for neurosurgical planning in children also.

AIM

This study aims to study the application of routine and advanced tractography algorithms and its comparison with intraoperative subcortical electrical stimulation.

METHOD

Presurgical functional MRI and MR diffusion tractography were performed on a 6-year-old patient presenting with seizures, but no motor symptoms, due to a neuroectodermal tumor in the left central region. Three different tractography algorithms were compared: deterministic diffusion tensor imaging (DTI)-tracking, probabilistic DTI-tracking, and probabilistic constrained spherical deconvolution tracking (pCSD).

RESULTS

All three tractography algorithms could localize the core of the corticospinal tract with good agreement. The pCSD-tracking algorithm was more sensitive in revealing the anatomically most realistic fiber distribution and a proportion of fibers traversing a solid part of the tumor. Intraoperative stimulation confirmed these fibers close to the tumor. As a result, only a subtotal resection was performed, preventing postoperative sensorimotor deficits.

CONCLUSION

Although, all tractography algorithms successfully identified the core of the corticospinal pathway, deterministic DTI-tractography, as widely used in clinical neuronavigation software, only insufficiently visualized critical fibers here. We believe these results argue for a stronger consideration of advanced tractography approaches in neurosurgical planning.

Isolated assessment of translation or rotation severely underestimates the effects of subject motion in fMRI data

Subject motion has long since been known to be a major confound in functional MRI studies of the human brain. For resting-state functional MRI in particular, data corruption due to motion artefacts has been shown to be most relevant. However, despite 6 parameters (3 for translations and 3 for rotations) being required to fully describe the head's motion trajectory between timepoints, not all are routinely used to assess subject motion. Using structural (n = 964) as well as functional MRI (n = 200) data from public repositories, a series of experiments was performed to assess the impact of using a reduced parameter set (translation_only and rotation_only) versus using the complete parameter set. It could be shown that the usage of 65 mm as an indicator of the average cortical distance is a valid approximation in adults, although care must be taken when comparing children and adults using the same measure. The effect of using slightly smaller or larger values is minimal. Further, both translation_only and rotation_only severely underestimate the full extent of subject motion; consequently, both translation_only and rotation_only discard substantially fewer datapoints when used for quality control purposes (“motion scrubbing”). Finally, both translation_only and rotation_only severely underperform in predicting the full extent of the signal changes and the overall variance explained by motion in functional MRI data. These results suggest that a comprehensive measure, taking into account all available parameters, should be used to characterize subject motion in fMRI.

Multidimensional morphometric 3D MRI analyses for detecting brain abnormalities in children: impact of control population

Automated morphometric approaches are used to detect epileptogenic structural abnormalities in 3D MR images in adults, using the variance of a control population to obtain z-score maps in an individual patient. Due to the substantial changes the developing human brain undergoes, performing such analyses in children is challenging. This study investigated six features derived from high-resolution T1 datasets in four groups: normal children (1.5T or 3T data), normal clinical scans (3T data), and patients with structural brain lesions (3T data), with each n = 10. Normative control data were obtained from the NIH study on normal brain development (n = 401). We show that control group size substantially influences the captured variance, directly impacting the patient's z-scores. Interestingly, matching on gender does not seem to be beneficial, which was unexpected. Using data obtained at higher field scanners produces slightly different base rates of suprathreshold voxels, as does using clinically derived normal studies, suggesting a subtle but systematic effect of both factors. Two approaches for controlling suprathreshold voxels in a multidimensional approach (combining features and requiring a minimum cluster size) were shown to be substantial and effective in reducing this number. Finally, specific strengths and limitations of such an approach could be demonstrated in individual cases.

A newborn with grouped facial skin lesions and subsequent seizures

BACKGROUND

Congenital grouped skin lesions are alarming signs of a variety of threatening diagnoses of quite different origin. The present case report shows an impressive clinical pattern of a neonate and illustrates the difficulty in differential diagnosis of mixed connective tissue disease and neonatal lupus erythematosus in newborns. This reported case is to our knowledge the first description of an unrecognized mixed connective tissue disease in the mother with an unusual clinical manifestation in the newborn, comprising skin lesions, neurological damage and non-typical antibody constellation.

CASE PRESENTATION

We report on a Caucasian female neonate from a perinatally asymptomatic mother, who presented with grouped facial pustular-like skin lesions, followed by focal clonic seizures caused by multiple ischemic brain lesions. Herpes simplex virus infection was excluded and both the mother and her infant had the antibody pattern of systemic lupus erythematosus and neonatal lupus erythematosus, respectively. However, clinical signs in the mother showed overlapping features of mixed connective tissue disease.

CONCLUSION

This case report emphasizes congenital Lupus erythematosus and mixed connective tissue disease as important differential diagnoses of grouped skin lesions in addition to Herpes simplex virus-infection. The coexistence of different criteria for mixed connective tissue disease makes it difficult to allocate precisely maternal and congenital infantile disease.

Mechanochemical synthesis and characterisation of two new bismuth metal organic frameworks

Two metal organic structures composed of the ligands benzene-1,4-dicarboxylate and pyridine-2,5-dicarboxylate and bismuth cations are presented: (H₂Im)[Bi(1,4-bdc)₂] (1) and [Bi(pydc)(NO₃)₂(H₂O)₂]·H₂O (2) (bdc = benzenedicarboxylate, H₂Im = imidazole cation, pydc = pyridinedicarboxylate).

Complex visual search in children and adolescents: effects of age and performance on fMRI activation

Complex visuospatial processing relies on distributed neural networks involving occipital, parietal and frontal brain regions. Effects of physiological maturation (during normal brain development) and proficiency on tasks requiring complex visuospatial processing have not yet been studied extensively, as they are almost invariably interrelated. We therefore aimed at dissociating the effects of age and performance on functional MRI (fMRI) activation in a complex visual search task. In our cross-sectional study, healthy children and adolescents (n = 43, 19 females, 7-17 years) performed a complex visual search task during fMRI. Resulting activation was analysed with regard to the differential effects of age and performance. Our results are compatible with an increase in the neural network's efficacy with age: within occipital and parietal cortex, the core regions of the visual exploration network, activation increased with age, and more so in the right than in the left hemisphere. Further, activation outside the visual search network decreased with age, mainly in left inferior frontal, middle temporal, and inferior parietal cortex. High-performers had stronger activation in right superior parietal cortex, suggesting a more mature visual search network. We could not see effects of age or performance in frontal cortex. Our results show that effects of physiological maturation and effects of performance, while usually intertwined, can be successfully disentangled and investigated using fMRI in children and adolescents.

Specific impairment of functional connectivity between language regions in former early preterms

Very preterm (PT) birth (≤32 weeks of gestation) carries a high risk for an adverse neurodevelopmental outcome. In recent years, the importance of neurocognitive deficits in the language domain has been increasingly recognized, which can be well-characterized using neuropsychological testing and noninvasive imaging approaches. We compared former early PT born children and adolescents (PT, n = 29, 20M) and typically developing children (TD, n = 19, 7M), using conventional fMRI group analyses as well as functional connectivity analyses. We found only small regions with significantly different group activation (PT > TD) but significantly stronger connectivity between superior temporal lobe (STL) language regions in TD participants. There were also significant differences in local and global network efficiency (TD > PT). Surprisingly, there was a stronger connectivity of STL regions with non-STL regions both intrahemispherically and interhemispherically in PT participants, suggesting the coexistence of reduced and increased connectivity in the language network of former PTs. Very similar results were obtained when using task-based versus resting state functional connectivity approaches. Finally, lateralization of functional connectivity correlated with verbal comprehension abilities, suggesting that a more bilateral language comprehension representation is associated with better performance. Our results underline the importance of interhemispheric crosstalk for language comprehension.

Two types of exercise-induced neuroplasticity in congenital hemiparesis: a transcranial magnetic stimulation, functional MRI, and magnetoencephalography study

AIM

Early unilateral brain lesions can lead to a persistence of ipsilateral corticospinal projections from the contralesional hemisphere, which can enable the contralesional hemisphere to exert motor control over the paretic hand. In contrast to the primary motor representation (M1), the primary somatosensory representation (S1) of the paretic hand always remains in the lesioned hemisphere. Here, we report on differences in exercise-induced neuroplasticity between individuals with such ipsilateral motor projections (ipsi) and individuals with early unilateral lesions but 'healthy' contralateral motor projections (contra).

METHOD

Sixteen children and young adults with congenital hemiparesis participated in the study (contralateral [Contra] group: n=7, four females, three males; age range 10-30y, median age 16y; ipsilateral [Ipsi] group: n=9, four females, five males; age range 11-31y, median age 12y; Manual Ability Classification System levels I to II in all individuals in both groups). The participants underwent a 12-day intervention of constraint-induced movement therapy (CIMT), consisting of individual training (2h/d) and group training (8h/d). Before and after CIMT, hand function was tested using the Wolf Motor Function Test (WMFT) and diverging neuroplastic effects were observed by transcranial magnetic stimulation (TMS), functional magnetic resonance imaging (fMRI), and magnetoencephalography (MEG). Statistical analysis of TMS data was performed using the non-parametric Wilcoxon signed-rank test for pair-wise comparison; for fMRI standard statistical parametric and non-parametric mapping (SPM5, SnPM3) procedures (first level/second level) were carried out. Statistical analyses of MEG data involved analyses of variance (ANOVA) and t-tests.

RESULTS

While MEG demonstrated a significant increase in S1 activation in both groups (p=0.012), TMS showed a decrease in M1 excitability in the Ipsi group (p=0.036), but an increase in M1 excitability in the Contra group (p=0.043). Similarly, fMRI showed a decrease in M1 activation in the Ipsi group, but an increase in activation in the M1-S1 region in the Contra group (for both groups p<0.001 [SnPM3] within the search volume).

INTERPRETATION

Different patterns of sensorimotor (re)organization in individuals with early unilateral lesions show, on a cortical level, different patterns of exercise-induced neuroplasticity. The findings help to improve the understanding of the general principles of sensorimotor learning and will help to develop more specific therapies for different pathologies in congenital hemiparesis.

Long-term neurobiological consequences of early postnatal hCMV-infection in former preterms: a functional MRI study

Early postnatal infection with human cytomegalovirus (hCMV) may contribute to an adverse cognitive outcome in early preterm-born children (PT). We here set out to explore whether long-term neurobiological consequences of such an infection are detectable using fMRI in children and adolescents who were born very preterm and who either did (PThCMV+ ) or did not (PT(hCMV-)) suffer from an early postnatal hCMV-infection, when compared with typically developing healthy control (HC) subjects. Overall, data from 71 children and adolescents could be included, 34 PT (of which 15 were PT(hCMV+) and 19 were PT(hCMV-)) and 37 HC. Using a recently established "dual use" fMRI task, we investigated language and visuospatial functions. There were significant activation differences in the left hippocampus (PT > HC and PT(hCMV+) > HC), and in the right anterior cingulate cortex (PT(hCMV-) > PT(hCMV+)) when performing the language task. Surprisingly, only a small region in the occipital cortex showed a significant activation difference (HC > PT(HCMV-)) when performing the visuospatial task. Targeted analyses revealed differences in gray matter volume, but not density, in several brain regions. Our results suggest that long-term neurobiological consequences of an early postnatal hCMV infection are detectable even in older children and adolescents formerly born very preterm, compatible with a higher effort when performing a cognitive task. This suggests that measures to prevent such an infection are warranted. Furthermore, an interrelation of brain structure and function was detected that may constitute a severe confound when using fMRI to compare structurally differing groups.

[Economic aspects of inpatient treatment for decompensated liver cirrhosis: a prospective study employing an evidence-based clinical pathway]

The introduction of the G-DRG reimbursement system has greatly increased the pressure to provide cost effective treatment in German hospitals. Reimbursement based on diagnosis-related groups, which requires stratification of costs incurred is still not sufficiently discriminating the disease severity and severity in relation to the intensive costs in gastroenterology. In a combined retrospective and prospective study at a tertial referral centre we investigated whether this also applies for decompensated liver cirrhosis. In 2006, 64 retrospective cases (age 57 ± 12.9; ♂ 69.2 %, ♀ 29.8 %) with decompensated liver cirrhosis (ICD code K76.4) were evaluated for their length of hospitalisation, reimbursement as well as Child and MELD scores. In 2008, 74 cases with decompensated liver cirrhosis were treated in a prospective study according to a standardised and evidence-based clinical pathway (age 57 ± 12.2; 73 % ♂, ♀ 27 %). Besides a trend in the reduction of length of hospital stay (retrospective: 13.6 ± 8.6, prospective 13.0 ± 7.2, p = 0.85) overall revenues from patients treated according to a evidence-based clinical pathway were lower than the calculated costs from the InEK matrix. Costs of medication as a percentage of reimbursement amount increased with increasing severity. In both years we could demonstrate an inverse correlation between daily reimbursement and disease severity which precluded cost coverage. For the cost-covering hospital treatment of patients with decompensated liver cirrhosis an adjustment of the DRG based on clinical severity scores such as Child-Pugh or MELD is warranted, if evidence-based treatment standards are to be kept.

Identification of successful clinical fMRI sessions in children: an objective approach

PURPOSE

The term clinical functional magnetic resonance imaging (fMRI) describes an examination with direct clinical impact on the patient. Interpretation of clinical fMRI especially in children, however, is often difficult due to suboptimal data quality. The current gold standard is standardized visual evaluation. To evaluate such data in an automated and objective way, we developed an approach to identify successful sessions.

METHODS

Average activation inside a predefined, task-specific region of interest (ROI) is compared with average activation in the rest of the brain, and their ratio (classification factor [Fc]) is determined for different statistical thresholds (T). The approach was tested and validated using 239 clinical pediatric fMRI sessions (sensorimotor, perceptive /productive language). Performance was assessed in terms of sensitivity, specificity, and positive likelihood ratio.

RESULTS

Best performance was found for Fc ≥ 2 and T ≥ 2.5, achieving a sensitivity of 0.87 and specificity of 0.94. Comparing the different domains, sensitivity was lowest for language production tasks, mainly due to atypical activation foci.

CONCLUSION

We demonstrate that an objective, automated framework for the classification of clinical pediatric fMRI sessions may provide important additional information, supporting visual evaluation, especially from sensorimotor and language perception domains. In the current form, atypical or strong network activation is not easily captured.

Cerebral gray and white matter changes and clinical course in metachromatic leukodystrophy

OBJECTIVE

Metachromatic leukodystrophy (MLD) is a rare metabolic disorder leading to demyelination and rapid neurologic deterioration. As therapeutic options evolve, it seems essential to understand and quantify progression of the natural disease. The aim of this study was to assess cerebral volumetric changes in children with MLD in comparison to normal controls and in relation to disease course.

METHOD

Eighteen patients with late-infantile MLD and 42 typically developing children in the same age range (20-59 months) were analyzed in a cross-sectional study. Patients underwent detailed genetic, biochemical, electrophysiologic, and clinical characterization. Cerebral gray matter (GM) and white matter (WM) volumes were assessed by multispectral segmentation of T1- and T2-weighted MRI. In addition, the demyelinated WM (demyelination load) was automatically quantified in T2-weighted images of the patients, and analyzed in relation to the clinical course.

RESULTS

WM volumes of patients did not differ from controls, although their growth curves were slightly different. GM volumes of patients, however, were on average 10.7% (confidence interval 6.0%-14.9%, p < 0.001) below those of normally developing children. The demyelination load (corrected for total WM volume) increased with disease duration (p < 0.003) and motor deterioration (p < 0.001).

CONCLUSION

GM volume in patients with MLD is reduced when compared with healthy controls, already at young age. This supports the notion that, beside demyelination, neuronal dysfunction caused by neuronal storage plays an additional role in the disease process. The demyelination load may be a useful noninvasive imaging marker for disease progression and may serve as reference for therapeutic intervention.