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Objective To characterize [11 C]-PBR28 brain uptake using positron emission tomography (PET) in people with amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS). We have previously shown increased [11 C]-PBR28 uptake in the precentral gyrus in a small group of ALS patients. Herein, we confirm our initial finding, study the longitudinal changes, and characterize the gray versus white matter distribution of [11 C]-PBR28 uptake in a larger cohort of patients with ALS and PLS. Methods Eighty-five participants including 53 with ALS, 11 with PLS, and 21 healthy controls underwent integrated [11 C]-PBR28 PET-magnetic resonance brain imaging. Patients were clinically assessed using the Upper Motor Neuron Burden (UMNB) and the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R). [11 C]-PBR28 uptake was quantified as standardized uptake value ratio (SUVR) and compared between groups. Cortical thickness and fractional anisotropy were compared between groups and correlated with SUVR and the clinical data. [11 C]-PBR28 uptake and ALSFRS-R were compared longitudinally over 6 months in 10 ALS individuals. Results Whole brain voxelwise, surface-based, and region of interest analyses revealed increased [11 C]-PBR28 uptake in the precentral and paracentral gyri in ALS, and in the subcortical white matter for the same regions in PLS, compared to controls. The increase in [11 C]-PBR28 uptake colocalized and correlated with cortical thinning, reduced fractional anisotropy, and increased mean diffusivity, and correlated with higher UMNB score. No significant changes were detected in [11 C]-PBR28 uptake over 6 months despite clinical progression. Interpretation Glial activation measured by in vivo [11 C]-PBR28 PET is increased in pathologically relevant regions in people with ALS and correlates with clinical measures. Ann Neurol 2018;83:1186-1197.

Objective To determine the relationship between brain tissue metabolites measured by in vivo magnetic resonance spectroscopy (1H-MRS), and glial activation assessed with [11C]-PBR28 uptake in people with amyotrophic lateral sclerosis (ALS). Methods Forty ALS participants were evaluated clinically using the revised ALS functional rating scale (ALSFRS-R) and upper motor neuron burden (UMNB). All participants underwent simultaneous brain [11C]-PBR28 PET and MR imaging including diffusion tensor imaging to acquire fractional anisotropy (FA). [11C]-PBR28 uptake was measured as standardized uptake values normalized by whole brain mean (SUVR). 1H-MRS metabolite ratios (myo-inositol/creatine, mI/Cr; N-acetylaspartate/creatine, NAA/Cr) were measured within the precentral gyri and brain stem (regions known to be involved in ALS pathophysiology), and precuneus (which served as a control region). Whole brain voxel-wise correlation analyses were employed to identify brain regions exhibiting an association between metabolites within the VOIs and [11C]-PBR28 uptake. Results In the precentral gyri, [11C]-PBR28 uptake correlated positively with mI/Cr and negatively with NAA/Cr. The same correlations were not statistically significant in the brain stem, or in the control precuneus region. Whole brain voxel-wise correlation analyses between the estimated brain metabolites within the VOIs and SUVR were highly correlated in the precentral gyri. Decreased FA values in the precentral gyri were correlated with reduced NAA/Cr and elevated mI/Cr. Higher UMNB was correlated with increased [11C]-PBR28 uptake and mI/Cr, and decreased NAA/Cr. ALSFRS-R total score correlated positively with NAA/Cr and negatively with mI/Cr. Conclusion Integrated PET-MR and 1H-MRS imaging demonstrates associations between markers for neuronal integrity and neuroinflammation and may provide valuable insights into disease mechanisms in ALS., Highlights • This study evaluates the relationship between 1H-MRS and [11C]-PBR28 PET-MR measures in people with ALS. • Myo-inositol/Creatine correlates positively with glial activation measured by [11C]-PBR28 PET, and negatively with fractional anisotropy. • N-acetyl-aspartate/Creatine correlates negatively with [11C]-PBR28 PET, and positively with fractional anisotropy. • Myo-inositol/Creatine and N-acetyl-aspartate/Creatine correlate with ALS-functional rating scale and upper motor neuron burden. • 1H-MRS and PET-MR measures provide complementary information to better understand brain pathology in people with ALS.

Patient: Female, 28 Final Diagnosis: Gastrinoma Symptoms: Vomiting • diarrhea • epigastric soreness • heartburn • nausea • significant weight loss Medication: — Clinical Procedure: Esophagogastroduodenoscopy • blood tests • abdomen CT scan • surgery Specialty: Gastroenterology and Hepatology Objective: Rare co-existance of disease or pathology Background: Pancreatic endocrine tumors (PETs) are rare and can occur as part of neurofibromatosis type 1 (NF1). Gastrinomas are functional PETs that are rarely associated with NF1. Only two cases of their occurrence have been reported in the literature. Case Report: A 28-year-old woman was admitted for further evaluation of epigastric soreness, heartburn, nausea, vomiting, diarrhea, and a significant weight loss. Physical examination was remarkable for cutaneous findings (axillary freckling and multiple café-au-lait spots) as well as neurofibromas (dermal, plexiform). A diagnosis of NF1 was confirmed. Esophagogastroduodenoscopy (EGD) revealed multiple ulcers in the duodenum and the upper jejunum. A fasting gastrin level exceeded ten times the normal limit. An abdominal multi-slice 128 computed tomography (CT) scan revealed an oval mass of 26 mm in diameter adjacent to the second segment of the duodenum. The patient was examined carefully to rule out multiple endocrine neoplasia type 1 (MEN1). Surgical resection was performed and a gastrinoma, causing Zollinger-Ellison syndrome (ZES), was diagnosed by histological examinations of the extirpated mass. The serum gastrin level decreased to normal limits shortly after surgery. Continuous follow-up revealed that the symptoms and the EGD findings completely resolved without recurrences. Conclusions: Although NF1 has common skeletal, visual, neurological, and cardiovascular complications, it also has a rare association with duodenal or pancreatic gastrinomas. Vigilance for this possible association is important to promote timely and careful management to help eliminate serious and potentially life-threatening complications.

Introduction There is an unmet need for mechanism-based biomarkers and effective disease modifying treatments in amyotrophic lateral sclerosis (ALS). Previous findings have provided evidence that histone deacetylases (HDAC) are altered in ALS, providing a rationale for testing HDAC inhibitors as a therapeutic option. Methods We measured class I and II HDAC protein and transcript levels together with acetylation levels of downstream substrates by using Western blotting in postmortem tissue of ALS and controls. [11 C]Martinostat, a novel HDAC positron emission tomography ligand, was also used to assess in vivo brain HDAC alterations in patients with ALS and healthy controls (HC). Results There was no significant difference in HDAC levels between patients with ALS and controls as measured by Western blotting and reverse-transcription quantitative polymerase chain reaction. Similarly, no differences were detected in [11 C]Martinostat-positron emission tomography uptake in ALS participants compared with HCs. Discussion These findings provide evidence that alterations in HDAC isoforms are not a dominant pathological feature at the bulk tissue level in ALS.

OBJECTIVE: To characterize [(11)C]-PBR28 brain uptake using positron emission tomography (PET) in people with amyotrophic lateral sclerosis (ALS), and primary lateral sclerosis (PLS). We have previously shown increased [(11)C]-PBR28 uptake in the precentral gyrus in a small group of ALS patients. Herein, we confirm our initial finding, study the longitudinal changes, and characterize the gray vs. white matter distribution of [(11)C]-PBR28 uptake in a larger cohort of patients with ALS and PLS. METHODS: Eighty-five participants including 53 ALS, 11 PLS and 21 healthy controls underwent integrated [(11)C]-PBR28 PET-MR brain imaging. Patients were clinically assessed using the upper motor neuron burden (UMNB), and the revised ALS functional rating scale (ALSFRS-R). [(11)C]-PBR28 uptake was quantified as standardized uptake value ratio (SUVR), and compared between groups. Cortical thickness, and fractional anisotropy were compared between groups and correlated with SUVR and the clinical data. [(11)C]-PBR28 uptake and ALSFRS-R were compared longitudinally over six-month in ten ALS individuals. RESULTS: Whole brain voxel-wise, surface-based and region of interest analyses revealed increased [(11)C]-PBR28 uptake in the precentral and paracentral gyri in ALS, and in the sub-cortical white matter for the same regions in PLS, compared to controls. The increase in [(11)C]-PBR28 uptake co-localized and correlated with cortical thinning, reduced fractional anisotropy, increased mean diffusivity, and correlated with higher UMNB score. No significant changes were detected in [(11)C]-PBR28 uptake over six-month despite clinical progression. INTERPRETATION: Glial activation measured by in vivo [(11)C]-PBR28 PET is increased in pathologically relevant regions in people with ALS and correlates with clinical measures.

Background Glia activation is thought to contribute to neuronal damage in several neurodegenerative diseases based on preclinical and human post-mortem studies, but its role in primary lateral sclerosis (PLS) is unknown. Objectives To localize and measure glia activation in people with PLS compared to healthy controls (HC). Methods Ten participants with PLS and ten age-matched HCs underwent simultaneous magnetic resonance (MR) and proton emission tomography (PET). The radiotracer [11C]-PBR28 was used to obtain PET-based measures of 18 kDa translocator protein (TSPO) expression, a marker of activated glial cells. MR techniques included a structural sequence to measure cortical thickness and diffusion tensor imaging (DTI) to assess white matter integrity. Results PET data showed increased [11C]-PBR28 uptake in anatomically-relevant motor regions which co-localized with areas of regional gray matter atrophy and decreased subcortical fractional anisotropy. Conclusions This study supports a link between glia activation and neuronal degeneration in PLS, and suggests that these disease mechanisms can be measured in vivo in PLS. Future studies are needed to determine the longitudinal changes of these imaging measures and to clarify if MR-PET with [11C]-PBR28 can be used as a biomarker for drug development in the context of clinical trials for PLS., Highlights • Is there a relationship between glia activation, cortical atrophy, and subcortical white matter abnormalities in people with primary lateral sclerosis (PLS)? • In this cross-sectional in vivo multi-modal (MR-PET) neuroimaging study, we show evidence of glia activation in the motor regions in PLS patients compared to healthy controls. The increased glia activation co-localizes with areas of structural abnormalities including cortical atrophy and subcortical white matter changes. • MR-PET neuroimaging is a powerful technique to localize and quantify glia activation and structural abnormalities, and may represent a novel in vivo biomarker of disease mechanisms in PLS.