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.