New insights into neuropathology and pathogenesis of autoimmune glial fibrillary acidic protein meningoencephalomyelitis.

Anti-glial fibrillary acidic protein (GFAP) meningoencephalomyelitis (autoimmune GFAP astrocytopathy) is a new autoimmune central nervous system (CNS) disease diagnosable by the presence of anti-GFAP autoantibodies in the cerebrospinal fluid and presents as meningoencephalomyelitis in the majority of patients. Only few neuropathological reports are available and little is known about the pathogenic mechanisms. We performed a histopathological study of two autopsies and nine CNS biopsies of patients with anti-GFAP autoantibodies and found predominantly a lymphocytic and in one autopsy case a granulomatous inflammatory phenotype. Inflammatory infiltrates were composed of B and T cells, including tissue-resident memory T cells. Although obvious astrocytic damage was absent in the GFAP-staining, we found cytotoxic T cell-mediated reactions reflected by the presence of CD8+/perforin+/granzyme A/B+ cells, polarized towards astrocytes. MHC-class-I was upregulated in reactive astrocytes of all biopsies and two autopsies but not in healthy controls. Importantly, we observed a prominent immunoreactivity of astrocytes with the complement factor C4d. Finally, we provided insight into an early phase of GFAP autoimmunity in an autopsy of a pug dog encephalitis that was characterized by marked meningoencephalitis with selective astrocytic damage with loss of GFAP and AQP4 in the lesions.Our histopathological findings indicate that a cytotoxic T cell-mediated immune reaction is present in GFAP autoimmunity. Complement C4d deposition on astrocytes could either represent the cause or consequence of astrocytic reactivity. Selective astrocytic damage is prominent in the early phase of GFAP autoimmunity in a canine autopsy case, but mild or absent in subacute and chronic stages in human disease, probably due to the high regeneration potential of astrocytes. The lymphocytic and granulomatous phenotypes might reflect different stages of lesion development or patient-specific modifications of the immune response. Future studies will be necessary to investigate possible implications of pathological subtypes for clinical disease course and therapeutic strategies.

Detection of Spinal Cord Multiple Sclerosis Lesions Using a 3D-PSIR Sequence at 1.5 T.

PURPOSE: Multiple sclerosis (MS) is a prevalent autoimmune inflammatory disease. Besides cerebral manifestations, an affection of the spinal cord is typical; however, imaging of the spinal cord is difficult due to its anatomy. The aim of this study was to assess the diagnostic value of a 3D PSIR pulse sequencing at a 1.5 T magnetic field strength for both the cervical and thoracic spinal cord. METHODS: Phase sensitive inversion recovery (PSIR), short tau inversion recovery (STIR) and T2-weighted (T2-w) images of the spinal cord of 50 patients were separately evaluated by three radiologists concerning the number and location of MS lesions. Furthermore, lesion to cord contrast ratios were determined for the cervical and thoracic spinal cord. RESULTS: Of the lesions 54.81% were located in the cervical spinal cord, 42.26% in the thoracic spinal cord and 2.93% in the conus medullaris. The PSIR images showed a higher sensitivity for lesion detection in the cervical and thoracic spinal cord (77.10% and 72.61%, respectively) compared to the STIR images (58.63% and 59.10%, respectively) and the T2-w images (59.95% and 59.52%, respectively). The average lesion to cord contrast ratio was significantly higher in the PSIR images compared to the STIR images (p < 0.001) and the T2-w images (p < 0.001). CONCLUSION: Evaluation of the spinal cord with a 3D PSIR sequence at a magnetic field strength of 1.5 T is feasible with a high sensitivity for the detection of spinal MS lesions for the cervical as well as the thoracic segments. In combination with other pulse sequences it might become a valuable addition in an advanced imaging protocol.

MRI signs of intracranial hypertension in morbidly obese and normal-weight individuals.

PURPOSE: Idiopathic intracranial hypertension (IIH) is associated with intracranial abnormalities, although not obligatory, which can be detected with cranial MRI. Obesity is an important risk factor for IIH and a pathogenetic link is suspected but the extent to which these MRI signs are already related to obesity has not yet been examined. We investigated whether IIH-MRI signs are present more often in obese individuals with a BMI > 30 kg/m² than in individuals of normal weight. MATERIALS AND METHODS: Brain MRI of 32 obese and 53 normal-weight participants from the Food-Chain-Plus cohort were analyzed for three main signs of IIH: (I) stenosis of the transverse sinus, (II) increased width of the optic nerve sheath, and (III) reduction of pituitary height. In addition, a scoring system for the MRI signs was applied. Furthermore, tortuosity of the optic nerve and flattening of the posterior globe were considered as additional MRI signs. RESULTS: Obese participants had a significantly higher MRI score (p < 0.001) than those in the normal-weight cohort, with significant differences in quantitative measurements of cerebral venous sinus stenosis (p < 0.001), widening of the optic nerve sheath (p < 0.05), and flattening of the pituitary gland (p < 0.05) also always being observed more frequently and in a more pronounced manner in the obese group. Furthermore, our findings correlated significantly with BMI and proportionately with hip and waist circumference. CONCLUSION: Obese individuals show a significantly higher prevalence of cerebral MRI signs related to IIH. This supports the hypothesis that obesity is a risk factor for possible intracranial hypertension and reinforces the suspicion that obesity is involved in the pathomechanism of IIH. KEY POINTS: · Obesity is associated with changes such as those seen in IIH.. · BMI, weight, and body measurements correlate with the expression of MRI signs of IIH.. · To prevent IIH symptoms in obesity, the pathomechanism must be further clarified..

Contour device implantation for treatment of intracranial aneurysms in the basilar tip.

INTRODUCTION: Treatment of basilar apex aneurysms will remain challenging regarding the nobility of the parent vessel and their often wide-necked configuration. With endovascular techniques being the treatment approach of choice, novel intrasaccular flow-disruption devices constitute an endovascular embolization option. In this research, we report our experiences in embolizing basilar tip aneurysms with the novel Contour device. MATERIAL AND METHODS: Retrospective analysis of eight patients after Contour implantation into a basilar apex aneurysm. Periprocedural data on intervention times, radiation dose, procedural success and complications were gathered. All patients received follow-up digital subtraction angiography after six months. Further follow-up examination results were analysed given their availability. RESULTS: Contour implantation was successful in all patients. The mean device instrumentation time was 18.8 ± 7.7 min with a mean full intervention time of 100 ± 65.8 min. The mean full procedure radiation dose was 1917 (421-5107) cGy/cm2. After six months, six aneurysms were occluded (Raymond Roy Scale (RRS) 1/2), one showed perfusion inside the device (RRS 3a) and one patient had undergone reintervention due to progression. The aneurysm with constant perfusion at six months was seen to be occluded after 24 months. CONCLUSION: Contour device implantation is a promising feasible alternative endovascular method for embolization of intracranial aneurysms located in the basilar tip with short intervention times and low radiation dosages. Short- and medium-term follow-ups show promising results concerning aneurysm occlusion and reinterventions, however further research is needed to show long-term stability.

Intra-cranial aneurysm treatment with contour or WEB - a single center comparison of intervention times and learning curves.

BACKGROUND AND PURPOSE: Treating aneurysms with intra-saccular flow disruption is a feasible alternative to coil-embolization. Besides the established WEB device, the novel Contour Neurovascular System has emerged as a potentially easier alternative regarding sizing and deployment. We report the learning curve experienced at our center from the first 48 patients treated with Contour and compared it with 48 consecutive WEB cases. METHODS: Both groups were compared concerning intervention time, sizing failures leading to device changes and radiation dose. Additionally, we analyzed potential learning effects by comparing the first 24 Contour cases with our last 24 Contour cases and WEB cases respectively. RESULTS: Patient demographics, acute vs. incidental cases and aneurysm localization were comparable in both groups. The deployment time was faster in our 48 Contour cases (median: 22.0 ± 17.0 min), than in the WEB group (median: 27.5 ± 24.0 min). Total intervention time was similar for Contour (median: 68.0 ± 46.9 min) and WEB cases (median: 69.0 ± 38.0 min). Device implantation times in our WEB cases were slightly shorter in the later cases (median: 25.5 ± 24.1 min) than in the earlier (median: 28.0 ± 24.4 min) cases. In the Contour cohort, deployment times were similar for the first 24 cases (median: 22.0 ± 14.5 min) and the final 24 (median: 22.0 ± 19.4 min). Radiation dose was lower in the Contour group (1469.0 ± 1718 mGy*cm2 vs. 1788.0 ± 1506 mGy*cm2 using the WEB device). Less intra-procedural device changes were performed in the Contour cohort (6 of 48 cases, 12.5%), than in the WEB group (8 of 48 cases, 16.7%). CONCLUSION: Aneurysm occlusion times and consequently radiation doses, as well as the amount of device changes were lower in the Contour group. Occlusion times did not differ in the first and last 24 Contour cases, leading to the assumption that the handling of Contour does not require extended training. A short training effect in occlusion times was noted, however, between the first and last WEB cases as shorter procedure times were seen in the latter cases.

Contour device implantation versus coil embolization for treatment of narrow neck intracranial aneurysms.

The novel Contour device is an intrasaccular flow disruption device designed for treatment of intracranial wide-neck bifurcation aneurysms. Outside its original purpose, Contour implantation can be used to treat aneurysms with a higher dome-to-neck ratio which would be suitable for conventional unassisted coil embolization. We compared both techniques in a retrospective single-center analysis. A total of 42 aneurysms from 42 patients with a dome-to-neck ratio of 1.6 or higher were included in this study. Data on technical success, implantation times, radiation dosages, procedural complications, reinterventions and recurrences were gathered and compared. Technical success was achieved in all cases with both techniques. Aneurysm embolization was achieved significantly faster in the Contour group compared to coiling (Overall p = 0.0002; r = 0.580; acute setting: p = 0.005, r = 0.531; elective setting: p = 0.002, r = 0.607). Significantly less radiation dosage was applied in the Contour group (Overall p = 0.002; r = 0.478; acute group p = 0.006; r = 0.552; elective group p = 0.045; r = 0.397). The number of complications was higher in the coiling group compared to the Contour group (Coiling 7/21 (33,3%); Contour 3/21 (14.3%). There was a higher rate of reinterventions in the coiling group (7.6% vs 21.4%). Outside its original intention, the Contour device seems to be a safe and fast alternative to coil embolization for the treatment of narrow-neck-aneurysms.

The effect of the size of the new contour neurovascular device for altering intraaneurysmal flow.

BACKGROUND: Recently, a novel intrasaccular device (contour neurovascular system, contour) was introduced to treat intracranial aneurysms. Contour is placed at thе aneurysm neck and reduces the intraaneurysmal blood inflow. Contour comes in a range of sizes to target different aneurysms. The efficiency of altering flow with contour and the effect of device size have not yet been investigated. Therefore, we studied the effect of the device size with patient-based aneurysm models using 2D digital subtraction angiography (DSA). METHODS: Three patient-based aneurysm models with necks ranging from 2.7 to 9.7 mm were produced, providing standardized testing conditions. Contours with diameters of 5, 11, and 14 mm were implanted into the models, four of each size. 2D DSA images were acquired before and after implanting contour (15 frames/s, manual contrast injection). After injecting angiographic contrast agent, the DSA signal was recorded over time to calculate the contrast washout time (WOT), which is a measure of flow diversion efficiency. RESULTS: All contour devices caused contrast agent stasis and increased WOT in aneurysm sac (p-value = 0.0005). The median relative WOT was largest for 5-mm contour (6.6 ± 3.2) and similar for 11-mm contour (3.4 ± 2.6) and 14-mm contour (3.2 ± 3.8). The implantation procedure might affect WOT values even for contours of the same size; the overall relative WOT ranged between 1.5 and 10.89. CONCLUSION: The 5-mm contour showed the longest WOT value in our study, while no apparent difference between 11-mm contour and 14-mm contour was found.

Determinants of compulsory hospitalisation at admission and in the course of inpatient treatment in people with mental disorders-a retrospective analysis of health records of the four psychiatric hospitals of the city of Cologne.

BACKGROUND: We aimed to identify differences in predictors of involuntary psychiatric hospitalisation depending on whether the inpatient stay was involuntary right from the beginning since admission or changed from voluntary to involuntary in the course of in-patient treatment. METHODS: We conducted an analysis of 1,773 mental health records of all cases treated under the Mental Health Act in the city of Cologne in the year 2011. 79.4% cases were admitted involuntarily and 20.6% were initially admitted on their own will and were detained later during the course of in-patient stay. We compared the clinical, sociodemographic, socioeconomic and environmental socioeconomic data (ESED) of the two groups. Finally, we employed two different machine learning decision-tree algorithms, Chi-squared Automatic Interaction Detection (CHAID) and Random Forest. RESULTS: Most of the investigated variables did not differ and those with significant differences showed consistently low effect sizes. In the CHAID analysis, the first node split was determined by the hospital the patient was treated at. The diagnosis of a psychotic disorder, an affective disorder, age, and previous outpatient treatment as well as the purchasing power per 100 inhabitants in the living area of the patients also played a role in the model. In the Random Forest, age and the treating hospital had the highest impact on the accuracy and decrease in Gini of the model. However, both models achieved a poor balanced accuracy. Overall, the decision-tree analyses did not yield a solid, causally interpretable prediction model. CONCLUSION: Cases with detention at admission and cases with detention in the course of in-patient treatment were largely similar in respect to the investigated variables. Our findings give no indication for possible differential preventive measures against coercion for the two subgroups. There is no need or rationale to differentiate the two subgroups in future studies.

Neural Correlates of Executed Compared to Imagined Writing and Drawing Movements: A Functional Magnetic Resonance Imaging Study.

Objective: In this study we used functional magnetic resonance imaging (fMRI) to investigate whether motor imagery (MI) of handwriting and circle drawing activates a similar handwriting network as writing and drawing itself. Methods: Eighteen healthy right-handed participants wrote the German word "Wellen" and drew continuously circles in a sitting (vertical position) and lying position (horizontal position) to capture kinematic handwriting parameters such as velocity, pressure and regularity of hand movements. Afterward, they performed the same tasks during fMRI in a MI and an executed condition. Results: The kinematic analysis revealed a general correlation of handwriting parameters during sitting and lying except of pen pressure during drawing. Writing compared to imagined writing was accompanied by an increased activity of the ipsilateral cerebellum and the contralateral sensorimotor cortex. Executed compared to imagined drawing revealed elevated activity of a fronto-parieto-temporal network. By contrasting writing and drawing directly, executed writing induced an enhanced activation of the left somatosensory and premotor area. The comparison of the MI of these tasks revealed a higher involvement of occipital activation during imagined writing. Conclusion: The kinematic results pointed to a high comparability of writing in a vertical and horizontal position. Overall, we observed highly overlapping cortical activity except of a higher involvement of motor control areas during motor execution. The sparse difference between writing and drawing can be explained by highly automatized writing in healthy individuals.

Evaluation of an Ultra-Short MRI Protocol for Cerebral Staging Examinations in Melanoma Patients.

PURPOSE: Due to its high sensitivity and lack of radiation, MRI is often used to stage cerebral tumors in patients. In contrast, the relatively long examination times and the limited availability of MRI slots at the clinic might delay these examinations. The aim of this study was to compare an ultra-short MRI protocol with the routinely used standard protocol. MATERIALS AND METHODS: Cerebral MRI of 147 patients with malignant melanoma were evaluated retrospectively, whereby only two sequences (FLAIR images and contrast-enhanced T1 MPR images) were evaluated in one group and images from the whole examination were available for the second group, including five sequences (DWI, T2 TSE, FLAIR, native and contrast-enhanced T1 TSE, and contrast-enhanced T1 MPR). The results of the two groups were compared and tested to determine whether the ultra-short approach was inferior to the full examination. RESULTS: 13.6 % of the patients had cerebral metastases. Overall, 73 metastases were detected: 60 were located supratentorially and 13 infratentorially. Concerning the detection of cerebral metastases, the ultra-short MRI examination, involving only a FLAIR and a contrast-enhanced T1 MPR sequence, was not inferior to the full MRI protocol in general (p = 0.017) and separated by location for supratentorial (p = 0.026) and infratentorial (p = 0.001) metastases. CONCLUSION: For staging purposes, a focused, ultra-short MRI protocol is not inferior to a standard MRI examination. This might open up opportunities for faster staging processes and a more efficient use of the often-restricted MRI capacities. KEY POINTS: · Short MRI protocols for cerebral staging are not inferior to standard examinations.. · Contrast-enhanced images represent the centerpiece of an ultra-short MRI protocol.. · Short MRI protocols might enable a more efficient use of restricted resources.. CITATION FORMAT: · Peters S, Gärtner F, Austein F et al. Evaluation of an Ultra-Short MRI Protocol for Cerebral Staging Examinations in Melanoma Patients. Fortschr Röntgenstr 2022; 194: 409 - 415.

[Diagnosis and treatment of vascular dementia]. / Vaskulär bedingte Demenzen erkennen und behandeln.

Vascular dementias (VD, due to the various expressions of VD the plural form is used) are the second most common form of dementia after Alzheimer's dementia. These dementias play an important role especially in geriatric patients. They can occur due to acute events (e.g. stroke) and due to slowly progressive cerebrovascular damage. This article focuses on VD due to cortical and strategic infarcts, microangiopathic infarcts with lacunae as well as intracerebral bleeding. In addition to the clinical description and radiological findings, a special focus is on education, prevention and rehabilitation aspects.

Intratumoral Distribution of Lactate and the Monocarboxylate Transporters 1 and 4 in Human Glioblastoma Multiforme and Their Relationships to Tumor Progression-Associated Markers.

(1) Background: Metabolic reprogramming has been postulated to be one of the hallmarks of cancer, thus representing a promising therapeutic target also in glioblastoma multiforme (GBM). Hypoxic tumor cells produce lactate, and monocarboxylate transporters (MCTs) play an important role in its distribution; (2) Methods: We examined the distribution of lactate by multi voxel magnetic resonance spectroscopic imaging and ELISA in glioblastoma multiforme (GBM) patients. In addition, we investigated the expression and cellular localization of MCT1, MCT4, and of several markers connected to tumor progression by quantitative PCR and immunofluorescence double-staining in human GBM ex vivo tissues; (3) Results: The highest lactate concentration was found at the center of the vital parts of the tumor. Three main GBM groups could be distinguished according to their regional gene expression differences of the investigated genes. MCT1 and MCT4 were found on cells undergoing epithelial to mesenchymal transition and on tumor stem-like cells. GBM cells revealing an expression of cellular dormancy markers, showed positive staining for MCT4; (4) Conclusion: Our findings indicate the existence of individual differences in the regional distribution of MCT1 and MCT4 and suggest that both transporters have distinct connections to GBM progression processes, which could contribute to the drug resistance of MCT-inhibitors.

MRI in patients with implanted active devices: how to combine safety and image quality using a limited transmission field?

OBJECTIVES: Radio frequency (RF) pulses in magnetic resonance imaging (MRI) can interact with implanted devices and cause tissue damage. However, there are new devices that can safely perform measurements with liberal MRI conditions such as an RF transmission field B1+rms ≤ 2.0 µT. We investigated whether MRI in this case is limited for these technical reasons. METHODS: We selected typical MRI protocols of six body regions (brain, cervical spine, lumbar spine, knee, liver, heart) using two typical 1.5T MRI scanners. Overall, we adapted 62 sequences to B1+rms conditions and evaluated their diagnostic quality. For this, we measured signal-to-noise-ratio (SNR), contrast-to-noise-ratio (CNR), and geometric deviation (GD) as quality parameters, using phantom studies. For questionnaire studies, we selected pairs of original and adapted sequences in healthy volunteers. Blinded radiologists rated the images as single sequence rating and in direct comparison. RESULTS: Roughly one-third of the checked sequences were below the B1+rms limit. Here, 56 of the 62 adapted sequences showed at least the same image quality in single ratings. A reduction in SNR and/or CNR was found with 31 sequences and only one sequence with considerably increased GD. Especially, sequences with original high B1+rms values, PD sequences, and sequences of the Siemens knee and heart protocol were difficult to adapt, whereas most TSE and IR sequences had no clinical limitations. CONCLUSION: By limiting the transmission field to B1+rms ≤ 2.0 µT, clinically relevant MR sequences can be adapted with nearly no reduction in image quality. Despite limiting the transmission field, high-quality MR imaging is possible. We could derive strategies for adaptation. KEY POINTS: • Despite limiting the transmission field, high-quality MRI is possible. • We could derive strategies for adapting the sequences to B1+rms≤ 2.0 µT. • This enables high-quality MRI of different body regions for patients with AD.

Effects of early HIV infection and combination antiretroviral therapy on intrinsic brain activity: a cross-sectional resting-state fMRI study.

Objective: To investigate effects of early HIV infection and combination antiretroviral therapy (cART) on intrinsic brain activity by using amplitude of low-frequency fluctuation (ALFF) analysis. Patients and methods: Forty-nine HIV patients, including 26 with cART (HIV+/cART+) and 23 treatment-naïve (HIV+/cART-), and 25 matched healthy controls (HCs) underwent resting-state functional magnetic resonance imaging examination. ALFF values were compared by using one-way ANOVA tests with Analysis of Functional NeuroImages (AFNI)'s 3dClustSim correction (voxel p<0.005, α<0.05). In addition, the ALFF values of brain regions that showed significant differences among the three groups were correlated with clinical and neuropsychological variables in both groups of patients by using Spearman correlation analysis. Results: ANOVA analysis showed that statistic difference of ALFF values among three groups was located in the occipital cortex. Post hoc analysis showed a decrease in occipital ALFF value in HIV patients compared to HC, but showed no difference of occipital ALFF between HIV+/cART+ and HIV+/cART-. Additionally, compared with HC, HIV+/cART+ exhibited higher ALFF in the right caudate and frontoparietal cortex, and HIV+/cART- showed higher ALFF in the bilateral caudate. HIV+/cART+ demonstrated higher ALFF values in auditory cortex than HIV+/cART-. Moreover, ALFF values in the right occipital cortex were positively associated with CD4+/CD8+ ratio and executive function in HIV+/cART-. Conclusion: Early HIV-infected individuals presented reduced spontaneous brain activity in the occipital cortex. cART appeared to be ineffective in halting the HIV-induced neurodegeneration but might delay the progression of neural dysfunction to some extent. ALFF might be a potential biomarker in monitoring the effects of HIV and cART on brain function.

Optimization of 3D phase contrast venography for the assessment of the cranio-cervical venous system at 1.5 T.

PURPOSE: The aim of this work was to optimize a three-dimensional (3D) phase-contrast venography (PCV) product MR pulse sequence in order to obtain clinically reliable images with less artifacts for an improved depiction of the cranio-cervical venous vessels. METHODS: Starting from the product sequence, the 3D PCV protocol was optimized in eight steps with respect to the velocity encoding (Venc) direction and value, slice thickness, reduction of susceptibility artifacts and arterial contamination, gradient mode and radio-frequency (RF)-spoiling, B0-Shimming, asymmetric echo technique and RF-pulse type, and flip angle. The product and optimized protocol was used to perform 3D PCV in 12 healthy male volunteers with a median age of 50 years using a state-of-the-art 1.5-T MR system. For evaluation, the cranio-cervical venous system was divided into 15 segments. These segments were evaluated by three radiologists with experience in neuroradiology. An ordinal scoring system was used to access the overall diagnostic quality, arterial contamination, and the quality of visualization. RESULTS: Image quality in the optimized 3D PCV was graded as "excellent" by all readers in 65.3% of the cases (p < 0.0001). The visualization of venous segments was strongly improved: it was considered diagnostic in 81.8% of all cases using the optimized sequence and in 47.6% for the product 3D PCV (p < 0.0001), respectively. The optimized protocol improved the imaging of all venous segments (p < 0.0001). CONCLUSION: The optimized 3D PCV pulse sequence showed superior results compared to the product 3D PCV for the visualization and evaluation of the venous system in all healthy volunteers.

Hypothalamic Inflammation in Human Obesity Is Mediated by Environmental and Genetic Factors.

Obesity is associated with hypothalamic inflammation (HI) in animal models. In the current study, we examined the mediobasal hypothalamus (MBH) of 57 obese human subjects and 54 age- and sex- matched nonobese control subjects by MRI and analyzed the T2 hyperintensity as a measure of HI. Obese subjects exhibited T2 hyperintensity in the left but not the right MBH, which was strongly associated with systemic low-grade inflammation. MRS revealed the number of neurons in the left hypothalamic region to be similar in obese versus control subjects, suggesting functional but not structural impairment due to the inflammatory process. To gain mechanistic insights, we performed nutritional analysis and 16S rDNA microbiome sequencing, which showed that high-fat diet induces reduction of Parasutterella sp. in the gut, which is significantly correlated with MBH T2 hyperintensity. In addition to these environmental factors, we found subjects carrying common polymorphisms in the JNK or the MC4R gene to be more susceptible to HI. Finally, in a subgroup analysis, bariatric surgery had no effect on MBH T2 hyperintensity despite inducing significant weight loss and improvement of peripheral insulin sensitivity. In conclusion, obesity in humans is associated with HI and disturbances in the gut-brain axis, which are influenced by both environmental and genetic factors.

Postoperative cognitive deficit after cardiopulmonary bypass with preserved cerebral oxygenation: a prospective observational pilot study.

BACKGROUND: Neurologic deficits after cardiac surgery are common complications. Aim of this prospective observational pilot study was to investigate the incidence of postoperative cognitive deficit (POCD) after cardiac surgery, provided that relevant decrease of cerebral oxygen saturation (cSO2) is avoided during cardiopulmonary bypass. METHODS: cSO2 was measured by near infrared spectroscopy in 35 patients during cardiopulmonary bypass. cSO2 was kept above 80% of baseline and above 55% during anesthesia including cardiopulmonary bypass. POCD was tested by trail making test, digit symbol substitution test, Ray's auditorial verbal learning test, digit span test and verbal fluency test the day before and 5 days after surgery. POCD was defined as a decline in test performance that exceeded - 20% from baseline in two tests or more. Correlation of POCD with lowest cSO2 and cSO2 - threshold were determined explorative. RESULTS: POCD was observed in 43% of patients. Lowest cSO2 during cardiopulmonary bypass was significantly correlated with POCD (p = 0.015, r2 = 0.44, without Bonferroni correction). A threshold of 65% for cSO2 was able to predict POCD with a sensitivity of 86.7% and a specificity of 65.0% (p = 0.03, without Bonferroni correction). CONCLUSIONS: Despite a relevant decrease of cerebral oxygen saturation was avoided in our pilot study during cardiopulmonary bypass, incidence of POCD was comparable to that reported in patients without monitoring. A higher threshold for cSO2 may be needed to reduce the incidence of POCD.