Showing papers by "Gereon R. Fink published in 2023"
TL;DR: In this article , surface-based fluorescence intensity distribution analysis (sFIDA) was used to detect and quantify single particles of α-synuclein aggregates in stool of 94 PD patients, 72 isolated rapid eye movement sleep behavior disorder (iRBD) patients, and 51 healthy controls.
Abstract: Misfolded and aggregated α-synuclein is a neuropathological hallmark of Parkinson's disease (PD). Thus, α-synuclein aggregates are regarded as a biomarker for the development of diagnostic assays. Quantification of α-synuclein aggregates in body fluids is challenging, and requires highly sensitive and specific assays. Recent studies suggest that α-synuclein aggregates may be shed into stool. We used surface-based fluorescence intensity distribution analysis (sFIDA) to detect and quantify single particles of α-synuclein aggregates in stool of 94 PD patients, 72 isolated rapid eye movement sleep behavior disorder (iRBD) patients, and 51 healthy controls. We measured significantly elevated concentrations of α-synuclein aggregates in stool of iRBD patients versus those of controls (p = 0.024) or PD patients (p < 0.001). Our results show that α-synuclein aggregates are excreted in stool and can be measured using the sFIDA assay, which could support the diagnosis of prodromal synucleinopathies.
3 citations
TL;DR: In this paper , the correspondence between subjective cognitive complaints (SCC) and objective results is investigated, and it is found that patients with SCC and objective impairment indicated elevated fatigue and reduced quality of life compared to patients without SCC at FU.
Abstract: Abstract: Cognitive impairment is a prominent symptom of the post-COVID syndrome (PCS). However, the correspondence between subjective cognitive complaints (SCC) and objective results is inconsistent. Here, we investigated this discrepancy. This longitudinal study included N = 42 individuals who reported SCC as PCS after mild infection at inclusion. Data collection comprised questionnaires and neuropsychological assessment at baseline and follow-up (FU). At FU – on average 15 months after acute COVID-19 – 88 % of patients reported persisting SCC. There was an approx. 40 % discrepancy between subjective report and test results at both visits. Patients with SCC and objective impairment indicated elevated fatigue and reduced quality of life compared to patients without SCC at FU. A growing number of patients is anticipated to request neuropsychological assessments even after mild infections.
2 citations
TL;DR: In this paper , the diagnostic value of amino acid PET tracers for patients with either glioblastoma or metastatic brain cancer was discussed, and the most important clinical indications for brain tumor patients are differentiation of neoplasm from non-neoplastic etiologies, delineation of tumor extent for further diagnostic and treatment planning, differentiation of treatment-related changes such as pseudoprogression or radiation necrosis after radiation or chemoradiation from tumor progression at follow-up, and assessment of response to anticancer therapy, including prediction of patient outcome.
Abstract: For decades, several amino acid PET tracers have been used to optimize diagnostics in patients with brain tumors. In clinical routine, the most important clinical indications for amino acid PET in brain tumor patients are differentiation of neoplasm from nonneoplastic etiologies, delineation of tumor extent for further diagnostic and treatment planning (i.e., diagnostic biopsy, resection, or radiotherapy), differentiation of treatment-related changes such as pseudoprogression or radiation necrosis after radiation or chemoradiation from tumor progression at follow-up, and assessment of response to anticancer therapy, including prediction of patient outcome. This continuing education article addresses the diagnostic value of amino acid PET for patients with either glioblastoma or metastatic brain cancer.
2 citations
TL;DR: In this article , a prospective, observational, international multicentre study with a 6-month follow-up, assessed the Non-Motor Symptom Scale (NMSS) as primary and the following secondary outcomes: Unified PD Rating Scale-motor examination (UPDRS-III), Scales for Outcomes in PD (SCOPA)-activities of daily living (ADL) and -motor complications, PDQuestionnaire-8 (PDQ-8), and levodopa-equivalent daily dose (LEDD).
2 citations
TL;DR: The expression of cAMP pathway genes Adora2a, Pde10a, and Drd2 was higher in poor- compared to well-recovered mice in contralesional primary motor cortex (cl-MOp) at 14, 28, and 56 days post-stroke (P14-56) as mentioned in this paper .
Abstract: Stroke patients show some degree of spontaneous functional recovery, but this is not sufficient to prevent long-term disability. One promising approach is to characterize the dynamics of stroke recovery genes in the lesion and distant areas. We induced sensorimotor cortex lesions in adult C57BL/6J mice using photothrombosis and performed qPCR on selected brain areas at 14, 28, and 56 days post-stroke (P14-56). Based on the grid walk and rotating beam test, the mice were classified into two groups. The expression of cAMP pathway genes Adora2a, Pde10a, and Drd2, was higher in poor- compared to well-recovered mice in contralesional primary motor cortex (cl-MOp) at P14&56 and cl-thalamus (cl-TH), but lower in cl-striatum (cl-Str) at P14 and cl-primary somatosensory cortex (cl-SSp) at P28. Plasticity and axonal sprouting genes, Lingo1 and BDNF, were decreased in cl-MOp at P14 and cl-Str at P28 and increased in cl-SSp at P28 and cl-Str at P14, respectively. In the cl-TH, Lingo1 was increased, and BDNF decreased at P14. Atrx, also involved in axonal sprouting, was only increased in poor-recovered mice in cl-MOp at P28. The results underline the gene expression dynamics and spatial variability and challenge existing theories of restricted neural plasticity.
1 citations
TL;DR: The preliminary version of the PDStigmaQuest was modified and is currently validated in a larger population of Parkinson's disease patients for use in clinical and research settings as mentioned in this paper , which is a feasible, comprehensive, and relevant tool to assess stigma in PD and helps to understand the construct of stigma further.
Abstract: BACKGROUND
Stigma is significant in Parkinson's disease (PD). However, no specific tool is available to assess stigma in PD comprehensively.
OBJECTIVE
This pilot study aimed to develop and test a stigma questionnaire specific to PD patients (PDStigmaQuest).
METHODS
Based on a literature review, clinical experience, expert consensus, and patients' feedback, we developed the preliminary, patient-completed PDStigmaQuest in German language. It included 28 items covering five stigma domains: uncomfortableness, anticipated stigma, hiding, experienced stigma, and internalized stigma. In this pilot study, 81 participants (PD patients, healthy controls, caregivers, and health professionals) were included to investigate the acceptability, feasibility, comprehensibility, and psychometric properties of the PDStigmaQuest.
RESULTS
The PDStigmaQuest showed 0.3% missing data points for PD patients and 0.4% for controls, suggesting high data quality. Moderate floor effects, but no ceiling effects were found. In the item analysis, most items met the standard criteria of item difficulty, item variance, and item-total correlation. Cronbach's alpha was > 0.7 for four of five domains. PD patients' domain scores were significantly higher than healthy controls' for uncomfortableness, anticipated stigma, and internalized stigma. Feedback to the questionnaire was predominantly positive.
CONCLUSION
Our results indicate that the PDStigmaQuest is a feasible, comprehensive, and relevant tool to assess stigma in PD and helps to understand the construct of stigma in PD further. Based on our results, the preliminary version of the PDStigmaQuest was modified and is currently validated in a larger population of PD patients for use in clinical and research settings.
TL;DR: In this article , the authors presented the case of a 23-year-old woman in whom an MRI suggested a cerebral venous sinus thrombosis and additional atypical MRI findings raised doubts regarding the initial diagnosis.
Abstract: ABSTRACT
Differentiating brain tumors from nonneoplastic lesions using conventional MRI may be challenging. Clinical symptoms often remain unspecific, and imaging findings from MRI may be inconclusive. We present the case of a 23-year-old woman in whom an MRI suggested a cerebral venous sinus thrombosis. On the other hand, additional atypical MRI findings raised doubts regarding the initial diagnosis. Given the need for a diagnostic procedure with higher sensitivity and specificity for neoplastic tissue, PET with the radiolabeled somatostatin receptor ligand DOTATATE (68Ga-DOTA-d-Phe1-Tyr3-octreotate) was performed. DOTATATE PET facilitated the diagnosis of a falcine meningioma consistent with its value for the differential diagnosis of meningioma.
TL;DR: In this paper , the utility of low beta-band suppression as a tool for contact selection in subthalamic deep brain stimulation (STN-DBS) for Parkinson's disease (PD) was evaluated.
TL;DR: In this article , the impact of different therapeutic strategies in the prehospital setting with a focus on levetiracetam was examined, and it appeared that the administered doses tended to be low.
Abstract: Background and Purpose Status epilepticus (SE) is a neurological emergency due to prolonged seizure activity or multiple seizures without full recovery in between them. Prehospital SE management is crucial since its duration is correlated with higher morbidity and mortality rates. We examined the impact of different therapeutic strategies in the prehospital setting with a focus on levetiracetam. Methods We initiated the Project for SE in Cologne, a scientific association of all neurological departments of Cologne, the fourth-largest city in Germany with around 1,000,000 inhabitants. All patients with an SE diagnosis were evaluated over 2 years (from March 2019 to February 2021) to determine whether prehospital levetiracetam use had a significant effect on SE parameters. Results We identified 145 patients who received initial drug therapy in the prehospital setting by professional medical staff. Various benzodiazepine (BZD) derivatives were used as first-line treatments, which were mostly used in line with the recommended guidelines. Levetiracetam was regularly used (n=42) and mostly in combination with BZDs, but no significant additional effect was observed for intravenous levetiracetam. However, it appeared that the administered doses tended to be low. Conclusions Levetiracetam can be applied to adults with SE in prehospital settings with little effort. Nevertheless, the prehospital treatment regimen described here for the first time did not significantly improve the preclinical cessation rate of SE. Future therapy concepts should be based on this, and the effects of higher doses should in particular be reexamined.
TL;DR: In this article , the authors used a support vector regression-based lesion-symptom mapping (SVR-LSM) method to identify the lesion correlates of effector-specific imitation deficits in stroke patients.
TL;DR: In this article , gender differences in DBS have been recognized for Parkinson's disease and the main reason was an underrepresentation of women in referrals for surgical evaluation for essential tremor (ET).
TL;DR: In this article , metabolic alterations in the occipital cortex during visual processing may serve as a biomarker for cognitive decline in patients with Parkinson's disease, which is a frequent and debilitating non-motor symptom for patients.
Abstract: Cognitive decline is a frequent and debilitating non‐motor symptom for patients with Parkinson's disease (PD). Metabolic alterations in the occipital cortex during visual processing may serve as a biomarker for cognitive decline in patients with PD.
TL;DR: In this paper , the authors used a monetary incentive grip force task where participants were asked to hold their grip force for high and low rewards at stake to maximize their monetary outcome, and found that severely impaired patients showed stronger incentive motivation, whereas early post-stroke depression symptoms were associated with reduced incentive motivation in the task.
TL;DR: In this paper , a fiber-based mapping approach, based on the calculation of fiber-wise Odds Ratio for SID, was employed to identify the distributional pattern of SID in the subthalamic nucleus vicinity.
Abstract: Objective This study aims to shed light on structural networks associated with stimulation-induced dysarthria (SID) and to derive a data-driven model to predict SID in patients with Parkinsons Disease (PD) and deep brain stimulation (DBS) of the subthalamic nucleus (STN). Methods Randomized, double-blinded monopolar reviews determining SID thresholds were conducted in 25 patients with PD and STN-DBS. A fiber-based mapping approach, based on the calculation of fiber-wise Odds Ratios for SID, was employed to identify the distributional pattern of SID in the STNs vicinity. The ability of the data-driven model to classify stimulation volumes as causing SID or not causing SID was validated by calculating receiver operating characteristics (ROC) in an independent out-of-sample cohort comprising 14 patients with PD and STN-DBS. Results Local fiber-based stimulation maps showed an involvement of fibers running lateral and postero-medial to the STN in the pathogenesis of SID, independent of the investigated hemisphere. ROC-analysis in the independent out-of-sample cohort resulted in a good fit of the data-driven model for both hemispheres (AUCleft = 0.88, AUCright = 0.88). Interpretation This study reveals an involvement of both, cerebello-thalamic fibers, as well as the pyramidal tract, in the pathogenesis of SID in STN-DBS. The results may impact future postoperative programming strategies to avoid SID in patients with PD and STN-DBS.
TL;DR: In this paper , the authors directly track underlying articulatory movements with electromagnetic articulography to investigate early speech alterations on the kinematic level in isolated REM sleep behavior disorder (iRBD) and compare them to control speakers and patients with Parkinson's disease (PD).
TL;DR: In this paper , the authors presented multimodal imaging findings in patients with glioblastoma with extensive coagulative necrosis related to regorafenib.
Abstract: Journal Article Multimodal imaging findings in patients with glioblastoma with extensive coagulative necrosis related to regorafenib Get access Jan-Michael Werner, Jan-Michael Werner Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany https://orcid.org/0000-0001-7147-4594 Search for other works by this author on: Oxford Academic PubMed Google Scholar Michael M Wollring, Michael M Wollring Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, GermanyInstitute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, Germany Search for other works by this author on: Oxford Academic PubMed Google Scholar Caroline Tscherpel, Caroline Tscherpel Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, GermanyInstitute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, Germany Search for other works by this author on: Oxford Academic PubMed Google Scholar Elena K Rosen, Elena K Rosen Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany Search for other works by this author on: Oxford Academic PubMed Google Scholar Lisa Werr, Lisa Werr Department of Experimental Pediatric Oncology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany Search for other works by this author on: Oxford Academic PubMed Google Scholar Isabelle Stetter, Isabelle Stetter Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany Search for other works by this author on: Oxford Academic PubMed Google Scholar Daniel Rueß, Daniel Rueß Department of Stereotactic and Functional Neurosurgery, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne,Germany Search for other works by this author on: Oxford Academic PubMed Google Scholar Maximilian I Ruge, Maximilian I Ruge Department of Stereotactic and Functional Neurosurgery, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne,Germany Search for other works by this author on: Oxford Academic PubMed Google Scholar Anna Brunn, Anna Brunn Institute of Neuropathology, Faculty of Medicine and University Hospital Cologne, Cologne, Germany Search for other works by this author on: Oxford Academic PubMed Google Scholar Abdulkader Al Shughri, Abdulkader Al Shughri Institute of Neuropathology, Faculty of Medicine and University Hospital Cologne, Cologne, Germany Search for other works by this author on: Oxford Academic PubMed Google Scholar ... Show more Christoph Kabbasch, Christoph Kabbasch Institure of Radiology, Division of Neuroradiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne,Germany Search for other works by this author on: Oxford Academic PubMed Google Scholar Gereon R Fink, Gereon R Fink Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, GermanyInstitute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, Germany Search for other works by this author on: Oxford Academic PubMed Google Scholar Karl-Josef Langen, Karl-Josef Langen Institute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, GermanyDepartment of Nuclear Medicine, University Hospital Aachen, Aachen, Germany Search for other works by this author on: Oxford Academic PubMed Google Scholar Norbert Galldiks Norbert Galldiks Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, GermanyInstitute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Juelich, GermanyCenter for Integrated Oncology (CIO), Universities of Aachen, Bonn, Cologne, and Duesseldorf, Cologne, Germany Corresponding Author: Norbert Galldiks, MD, Institute of Neuroscience and Medicine (INM-3), Research Center Juelich, Leo-Brandt-St. 5, 52425 Juelich, Germany, (n.galldiks@fz-juelich.de); Department of Neurology, University Hospital Cologne, Josef-Stelzmann St. 9, 50937 Cologne, Germany (norbert.galldiks@uk-koeln.de). https://orcid.org/0000-0002-2485-1796 Search for other works by this author on: Oxford Academic PubMed Google Scholar Neuro-Oncology, Volume 25, Issue 6, June 2023, Pages 1193–1195, https://doi.org/10.1093/neuonc/noad051 Published: 24 March 2023 Article history Corrected and typeset: 24 March 2023 Published: 24 March 2023
TL;DR: In this paper , the authors investigated the impact of intravenous immunoglobulin (IVIg) treatment on the gut microbiome in CIDP patients and found an increased alpha-diversity (p=0.005) and enrichment of Firmicutes, such as Blautia, Eubacterium hallii, or Ruminococcus torques, compared to healthy subjects.
Abstract: BACKGROUND
The gut microbiome is involved in autoimmunity. Data about its composition in chronic inflammatory demyelinating polyneuropathy (CIDP), the most common autoimmune disorder of peripheral nerves, are currently lacking.
METHODS
In this monocentric exploratory pilot study, stool samples were prospectively collected from 16 CIDP patients (mean age 58 ± 10 years, 25 % female) before and one week after administration of intravenous immunoglobulin (IVIg). Gut microbiota were analyzed via bacterial 16S rRNA gene sequencing and compared to 15 age-matched healthy subjects (mean age 59 ± 15 years, 66 % female).
RESULTS
Gut microbiota of CIDP patients showed an increased alpha-diversity (p=0.005) and enrichment of Firmicutes, such as Blautia (p=0.0004), Eubacterium hallii (p=0.0004), or Ruminococcus torques (p=0.03), and of Actinobacteriota (p=0.03) compared to healthy subjects. IVIg administration did not alter the gut microbiome composition in CIDP in a short-term observation (p=0.95).
CONCLUSIONS
The gut microbiome in IVIg-treated CIDP shows distinct features with increased bacterial diversity and enrichment of short-chain fatty acid (SCFA) producing Firmicutes. IVIg had no short-term impact on the gut microbiome in CIDP patients. As small cohort size is a main limitation of this exploratory pilot study, future studies also including therapy-naïve patients are warranted to verify our findings and to explore the impact of a long-term IVIg treatment on the gut microbiome in CIDP.
TL;DR: In this paper , the authors evaluated the potential neuro-regenerative effects of the small molecule kinesin-5 inhibitor monastrol in a rodent model of acute autoimmune neuropathies, experimental autoimmune neuritis.
Abstract: Abstract Background Autoimmune neuropathies can result in long-term disability and incomplete recovery, despite adequate first-line therapy. Kinesin-5 inhibition was shown to accelerate neurite outgrowth in different preclinical studies. Here, we evaluated the potential neuro-regenerative effects of the small molecule kinesin-5 inhibitor monastrol in a rodent model of acute autoimmune neuropathies, experimental autoimmune neuritis. Methods Experimental autoimmune neuritis was induced in Lewis rats with the neurogenic P2-peptide. At the beginning of the recovery phase at day 18, the animals were treated with 1 mg/kg monastrol or sham and observed until day 30 post-immunisation. Electrophysiological and histological analysis for markers of inflammation and remyelination of the sciatic nerve were performed. Neuromuscular junctions of the tibialis anterior muscles were analysed for reinnervation. We further treated human induced pluripotent stem cells-derived secondary motor neurons with monastrol in different concentrations and performed a neurite outgrowth assay. Results Treatment with monastrol enhanced functional and histological recovery in experimental autoimmune neuritis. Motor nerve conduction velocity at day 30 in the treated animals was comparable to pre-neuritis values. Monastrol-treated animals showed partially reinnervated or intact neuromuscular junctions. A significant and dose-dependent accelerated neurite outgrowth was observed after kinesin-5 inhibition as a possible mode of action. Conclusion Pharmacological kinesin-5 inhibition improves the functional outcome in experimental autoimmune neuritis through accelerated motor neurite outgrowth and histological recovery. This approach could be of interest to improve the outcome of autoimmune neuropathy patients.
TL;DR: In this paper , the authors analyzed resting-state EEG data from young, healthy participants acquired on five consecutive days before and after a motor task and revealed four stable topographic patterns over the multiple recording sessions.
Abstract: The resting human brain cycles through distinct states that can be analyzed using microstate analysis and electroencephalography (EEG) data. In this approach, multi-channel EEG scalp recordings are classified into spontaneously interchanging microstates based on topographic features. These microstates may be valuable biomarkers in neurodegenerative diseases since they reflect the resting brain’s state. However, microstates do not provide information about the active neural networks during the resting-state. This article presents an alternative and complementary method for analyzing resting-state EEG data and demonstrate its reproducibility and reliability. This method considers cerebral connectivity states defined by phase synchronization measured using the corrected imaginary phase-locking value (ciPLV) based on source-reconstructed EEG recordings. We analyzed resting-state EEG data from young, healthy participants acquired on five consecutive days before and after a motor task. We show that our data reproduce the microstates previously reported. In source connectivity space, we reveal four stable topographic patterns over the multiple recording sessions. Besides, while the classical microstates were unaffected by the preceding motor task, the connectivity states were altered reflecting suppression of frontal activity in the post-movement resting state.
TL;DR: In this article , the authors investigated the associations between serum cortisol levels, hippocampal volume, gray matter volume and memory performance in healthy aging and Alzheimer's disease (AD) and found that higher cortisol levels were significantly associated with smaller left hippocampal volumes in HS and indirectly negatively correlated to memory function through hippocampusal volume.
Abstract: Objective Elevated cortisol levels have been frequently reported in Alzheimer’s disease (AD) and linked to brain atrophy, especially of the hippocampus. Besides, high cortisol levels have been shown to impair memory performance and increase the risk of developing AD in healthy individuals. We investigated the associations between serum cortisol levels, hippocampal volume, gray matter volume and memory performance in healthy aging and AD. Methods In our cross-sectional study, we analyzed the relationships between morning serum cortisol levels, verbal memory performance, hippocampal volume, and whole-brain voxel-wise gray matter volume in an independent sample of 29 healthy seniors (HS) and 29 patients along the spectrum of biomarker-based AD. Results Cortisol levels were significantly elevated in patients with AD as compared to HS, and higher cortisol levels were correlated with worse memory performance in AD. Furthermore, higher cortisol levels were significantly associated with smaller left hippocampal volumes in HS and indirectly negatively correlated to memory function through hippocampal volume. Higher cortisol levels were further related to lower gray matter volume in the hippocampus and temporal and parietal areas in the left hemisphere in both groups. The strength of this association was similar in HS and AD. Conclusion In AD, cortisol levels are elevated and associated with worse memory performance. Furthermore, in healthy seniors, higher cortisol levels show a detrimental relationship with brain regions typically affected by AD. Thus, increased cortisol levels seem to be indirectly linked to worse memory function even in otherwise healthy individuals. Cortisol may therefore not only serve as a biomarker of increased risk for AD, but maybe even more importantly, as an early target for preventive and therapeutic interventions.
TL;DR: In this paper , isolated rapid eye movement (REM) sleep behavior disorder (iRBD) cohorts have provided insights into the earliest neurodegenerative processes in α-synucleinopathies.
Abstract: Isolated rapid eye movement (REM) sleep behavior disorder (iRBD) cohorts have provided insights into the earliest neurodegenerative processes in α‐synucleinopathies. Even though polysomnography (PSG) remains the gold standard for diagnosis, an accurate questionnaire‐based algorithm to identify eligible subjects could facilitate efficient recruitment in research.
TL;DR: In this article , the authors investigated two different mechanisms of glutamate signaling in patients with Parkinson's disease and Rapid Eye Movement (REM) sleep behavior disorder (RBD) by combining magnetic resonance (MR) spectroscopy and 11C-ABP688 positron emission tomography (PET) on a hybrid system.
Abstract: Background and Objectives: Clinical heterogeneity of patients with Parkinson's disease is well recognized. Parkinson's disease with rapid eye movement (REM) sleep behavior disorder (RBD) is a more malignant phenotype with faster motor progression and higher non-motor symptom burden. However, the neural mechanisms underlying this clinical divergence concerning disbalances in neurotransmitter systems remain elusive. Methods: Combining magnetic resonance (MR) spectroscopy and 11C-ABP688 positron emission tomography (PET) on PET/MR hybrid system, we simultaneously investigated two different mechanisms of glutamate signaling in patients with Parkinson's disease. Thirty-three patients were grouped according to their RBD status in overnight video-polysomnography and compared to 15 age- and sex-matched healthy control (HC) subjects. Total volumes of distribution (VT) of 11C-ABP688 were estimated with metabolite-corrected plasma concentrations during steady-state conditions between minutes 45 to 60 of the scan following a bolus-infusion protocol. Glutamate, glutamine, and glutathione levels were investigated with single voxel STEAM MR spectroscopy of the left putamen. Results: We measured globally elevated VT of 11C-ABP688 in patients with Parkinson's disease and RBD compared to patients without RBD and HC subjects (F(2,45) = 5.579, p = 0.007). Conversely, glutamatergic metabolites did not differ between groups and did not correlate with the regional VT of 11C-ABP688. VT of 11C-ABP688 correlated with the amount of REM sleep without atonia (F(1,42) = 5.600, p = 0.023), and with dopaminergic treatment response in Parkinson's disease patients (F(1,30) = 5.823, p = 0.022). Conclusion: Our results suggest that patients with Parkinson's disease and RBD exhibit altered glutamatergic signaling indicated by higher VT of 11C-ABP688 despite unaffected glutamate metabolism. The disbalance of glutamate receptors and neurotransmitter might indicate a novel mechanism contributing to the heterogeneity of Parkinson's disease and warrants further investigation of drugs targeting mGluR5.
TL;DR: In this article , a review summarizes recent advances in PET imaging helpful for improving the clinical management of patients with meningioma, showing that metabolic imaging using PET may help to characterize specific metabolic and cellular features providing additional information beyond the information derived from anatomical imaging alone.
Abstract: Abstract In patients with meningioma, diagnosis and treatment planning are predominantly based on anatomical imaging using MRI or CT. Constraints of these imaging modalities include precise meningioma delineation—especially at the skull base, in the case of trans-osseus growth, and in tumors with complex geometry—and the differentiation of post-therapeutic reactive changes from meningioma relapse. Advanced metabolic imaging using PET may help to characterize specific metabolic and cellular features providing additional information beyond the information derived from anatomical imaging alone. Accordingly, the use of PET in meningioma patients is steadily increasing. This review summarizes recent advances in PET imaging helpful for improving the clinical management of patients with meningioma.