Diagnostic Superiority of 18 F-FDG PET Over MRI in Detecting Anti-LGI1 Autoimmune Encephalitis : A Comparative Study With Insights Into Faciobrachial Dystonic Seizures Mechanisms and Recurrence Identification.

OBJECTIVE: Our study aimed to investigate the utility of 18 F-FDG PET imaging in diagnosing and monitoring patients with anti-leucine-rich glioma-inactivated 1 antibody autoimmune encephalitis (anti-LGI1 AE). We also sought to understand the mechanisms of faciobrachial dystonic seizures (FBDSs). PATIENTS AND METHODS: We analyzed 18 F-FDG PET scans from 50 patients with anti-LGI1 AE, using visual and semiquantitative methods, and compared these with 24 healthy controls. All patients tested positive for anti-LGI1 antibodies in serum or cerebrospinal fluid before PET imaging. The patients were divided into FBDS and non-FBDS groups to compare metabolic differences using voxel-based semiquantitative analysis. Finally, we separately analyzed PET images of patients with symptom recurrence. RESULTS: The sensitivity of 18 F-FDG PET was superior to MRI (97.9% vs 63.8%, respectively; P < 0.001). Semiquantitative analysis revealed hypermetabolism in the basal ganglia, medial temporal lobe, and brainstem, and hypometabolism in most neocortical regions compared with healthy controls. The FBDS group exhibited hypometabolism in the frontal and temporal lobes compared with the non-FBDS group. Among 7 recurrent patients, 3 were confirmed as recurrence and 3 as sequelae by PET. One patient relapsed shortly after discontinuing corticosteroids when PET indicated active lesions. CONCLUSIONS: 18 F-FDG PET scans were more sensitive than MRI in detecting anti-LGI1 AE, which displayed a pattern of hypermetabolism in the basal ganglia and medial temporal lobe, as well as neocortex hypometabolism. Hypometabolism in the frontal and temporal lobes was associated with FBDS. Furthermore, 18 F-FDG PET scans can differentiate recurrence from sequelae and guide the timing of immunotherapy cessation.

Generalized Muscular Hypermetabolism Caused by Mitochondrial Myopathy Shown on 18 F-FDG PET/CT.

ABSTRACT: An 18-year-old man presented with progressive exercise intolerance and muscle weakness for 1 year with recent acute exacerbation. Laboratory test demonstrated lactic acidosis. 18 F-FDG PET/CT was performed to exclude malignancy and showed generalized muscular hypermetabolism. Muscle biopsy combined with patient's history suggested mitochondrial myopathy. This report illustrates that mitochondrial myopathy may present as generalized muscular hypermetabolism on 18 F-FDG PET/CT and thus should be added to the differential diagnoses.

Neurological disorders associated with glutamic acid decarboxylase 65 antibodies: Clinical spectrum and prognosis of a cohort from China.

Objective: To describe clinical phenotypes and prognosis of neurological autoimmunity related to glutamic acid decarboxylase 65 (GAD65) antibodies in China. Method: In this retrospective observational study from Peking Union Medical College Hospital, we identified patients with neurological disorders related to GAD65 antibodies (cell-based assay) from May 2015 to September 2021. Clinical manifestations, immunotherapy responsiveness, and outcomes were collected after obtaining informed consent from all patients. Results: Fifty-five patients were included: 40 (72.73%) were women and initial neurological symptoms developed at 42(34-55) years of age. The median time to the nadir of the disease was 5 months (range from 1 day to 48 months). The clinical syndromes included limbic encephalitis (LE) or epilepsy (Ep) (n = 34, 61.82%), stiff-person syndromes (SPS) (n = 18, 32.73%), autoimmune cerebellar ataxia (ACA) (n = 11, 20%), and overlap syndrome in eight (14.55%) patients. Thirty-two (58.2%) patients had comorbidities of other autoimmune diseases, including Hashimoto thyroiditis (n = 17, 53.13%), T1DM (n = 11, 34.78%), vitiligo (n = 6, 18.75%), and others (n=5, 15.63%). Two (3.64%) patients had tumors, including thymoma and small cell lung cancer. Fifty-one (92.7%) patients received first-line immunotherapy (glucocorticoids and/or IV immunoglobulin), and 4 (7.3%) received second-line immunotherapy (rituximab). Long-term immunotherapy (mycophenolate mofetil) was administered to 23 (41.8%) patients. At the median time of 15 months (IQR 6-33.75 month, range 3-96 month) of follow-up, the patients' median modified Rankin Score (mRS) had declined from 2 to 1. Thirty-eight (70.4%) patients experienced clinical improvement (mRS declined ≥1), 47 (87%) had favorable clinical outcomes (mRS ≤2), and nine were symptom-free (16.7%). The sustained response to immunotherapy ranged from 7/15 (63.63%) in ACA patients and 22/34 (64.7%) in LE/Ep patients to 14/17 (82.35%) in SPS patients. Conclusions: LE/Ep was the most common neurological phenotype of GAD65 antibody neurological autoimmunity in our cohort. Most patients had comorbidities of other autoimmune diseases, but underlying tumors were rare. Most patients responded to immunotherapy. However, the long-term prognosis varied among different clinical phenotypes.

Extracorporeal Membrane Oxygenation (ECMO) in Critically Ill Patients with Coronavirus Disease 2019 (COVID-19) Pneumonia and Acute Respiratory Distress Syndrome (ARDS).

Traced back to December 2019, an unexpected outbreak of a highly contagious new coronavirus pneumonia (COVID-19) has rapidly swept around China and the globe. There have now been an estimated 2 580 000 infections and more than 170 000 fatal cases around the world. The World Health Organization (WHO) estimated that approximately 14% of infections developed into severe disease, 5% were critically ill, and the mortality rate of critically ill patients is reported to be over 50%. The shortage of specific anti-viral treatment and vaccines remains a huge challenge. In COVID-19, refractory hypoxemia is common among the critically ill with acute respiratory distress syndrome (ARDS) despite invasive mechanical ventilation, and is further complicated by respiratory and circulatory failure. This difficult situation calls for the use of extracorporeal membrane oxygenation (ECMO) for assisting respiration and circulation if necessary. This article reviews the pertinent clinical literature, technical guidance, and expert recommendations on use of ECMO in critically ill cases of COVID-19. Here, we present basic knowledge and opinions about COVID-19 and ECMO, review the evidence on ECMO use in Middle East Respiratory Syndrome (MERS) and H1N1 influenza, share the technical guidance and recommendations on use of ECMO in COVID-19, summarize the current use of ECMO against COVID-19 in China, and discuss the issues in use of ECMO in COVID-19.