Stroke associated with sarcoidosis: A systematic review of reported cases.

BACKGROUND: Sarcoidosis can be associated with stroke. Whether granulomatous vasculitis directly causes stroke in patients with sarcoidosis remains unclear. This systematic review aims to consolidate reports of concurrent sarcoidosis and stroke. METHODS: Medline and Embase were searched for terms encompassing sarcoidosis and stroke with a censoring date of March 25, 2023. Cases were reviewed by two authors, with the inclusion criteria: biopsy-confirmed systemic sarcoidosis, stroke confirmed by imaging or pathology, clinical description of individual patient history, and English language publications. RESULTS: Of 1628 articles screened, 51 patients from 49 articles were included (65% male, mean age 41 years). Seventy-one percent of strokes were ischemic and 29% were hemorrhagic. Lesions were supratentorial in 78% of cases, infratentorial in 34%, and multifocal in 45%. Presenting symptoms were variable, with the most common being headache (38%) followed by weakness (35%). 10 patients had recurrent strokes. Stroke was the presenting symptom of sarcoidosis in 65%. 21 patients had brain biopsies. The most common neuropathologic findings were perivascular (33%) or intramural (33%) non-caseating granulomas. On imaging, 32 patients had findings suggestive of neurosarcoidosis, including 35% with evidence of meningeal enhancement. 63% of patients were treated with corticosteroids and/or other immunomodulatory therapy, with varying clinical improvement. CONCLUSIONS: Stroke associated with sarcoidosis generally follows trends in stroke incidence, with infarction being more common than hemorrhage and male sex carrying a higher risk. Most patients were diagnosed with sarcoidosis during or following their stroke episode. Brain biopsy infrequently shows clear granulomatous vasculitis.

Herpes Simplex Virus Encephalitis in Patients With Autoimmune Conditions or Exposure to Immunomodulatory Medications.

BACKGROUND AND OBJECTIVES: Among infectious etiologies of encephalitis, herpes simplex virus type 1 (HSV-1) is most common, accounting for ∼15%-40% of adult encephalitis diagnoses. We aim to investigate the association between immune status and HSV encephalitis (HSVE). Using a US Medicaid database of 75.6 million persons, we evaluated the association between HSVE and autoimmune conditions, exposure to immunosuppressive and immunomodulatory medications, and other medical comorbidities. METHODS: We used the US Medicaid Analytic eXtract data between 2007 and 2010 from the 29 most populated American states. We first examined the crude incidence of HSVE in the population. We then age and sex-matched adult cases of HSVE with a sufficient enrollment period (12 months before HSVE diagnosis) to a larger control population without HSVE. In a case-control analysis, we examined the association between HSVE and exposure to both autoimmune disease and immunosuppressive/immunomodulatory medications. Analyses were conducted with conditional logistic regression progressively adjusting for sociodemographic factors, Charlson Comorbidity Index, and non-autoimmune comorbidities. RESULTS: Incidence of HSVE was ∼3.01 per 105 person-years among adults. A total of 951 HSVE cases and 95,100 age and sex-matched controls were compared. The HSVE population had higher rates of medical comorbidities than the control population. The association of HSVE and autoimmune conditions was strong (adjusted odds ratio (OR) 2.6; 95% CI 2.2-3.2). The association of HSVE and immunomodulating medications had an OR of 2.2 (CI 1.9-2.6), also after covariate adjustment. When both exposures were included in regression models, the associations remained robust: OR 2.3 (CI 1.9-2.7) for autoimmune disease and 2.0 (CI 1.7-2.3) for immunosuppressive and immunomodulatory medications. DISCUSSION: In a large, national population, HSVE is strongly associated with preexisting autoimmune disease and exposure to immunosuppressive and immunomodulatory medications. The role of antecedent immune-related dysregulation may have been underestimated to date.

Infectious Myelopathies.

OBJECTIVE: Infectious myelopathy of any stage and etiology carries the potential for significant morbidity and mortality. This article details the clinical presentation, risk factors, and key diagnostic components of infectious myelopathies with the goal of improving the recognition of these disorders and guiding subsequent management. LATEST DEVELOPMENTS: Despite our era of advanced multimodal imaging and laboratory diagnostic technology, a causative organism often remains unidentified in suspected infectious and parainfectious myelopathy cases. To improve diagnostic capability, newer technologies such as metagenomics are being harnessed to develop diagnostic assays with a greater breadth of data from each specimen and improvements in infection identification. Conventional assays have been optimized for improved sensitivity and specificity. ESSENTIAL POINTS: Prompt recognition and treatment of infectious myelopathy decreases morbidity and mortality. The key diagnostic tools include serologies, CSF analysis, and imaging; however clinical presentation, epidemiologic risk factors, and history of recent illness are all vital to making the proper diagnosis because current laboratory and imaging modalities are often inconclusive. The cornerstone of recommended treatment is targeted antimicrobials with appropriate immune modulation, surgical intervention, supportive care, and interdisciplinary involvement, all of which further improve outcomes for patients with infectious myelopathy.

Disease modifying therapy in the treatment of tumefactive multiple sclerosis: A retrospective cohort study.

Tumefactive multiple sclerosis (TMS) is characterized by large demyelinating brain lesions. This was a retrospective cohort study of 67 patients with TMS between January 2015-2023, examining different disease modifying therapy impact on expanded disability scale score change at follow-up. Median age was 36 with a female predominance. Mean EDSS was 3.3 ± 2.3 at TMS onset, 2.1 ± 1.9 at year one, and 2.1 ± 1.9 at last follow-up. A multilinear regression model found higher presentation EDSS and post-diagnosis non-B-cell high efficacy therapies were each independently associated with higher EDSS at last follow up. Further research is needed to determine the value of B-cell therapy in TMS.

MYD88 L265P mutation in neurologic autoimmunity without evidence of malignancy.

MYD88 mutation status is assessed in the evaluation of CNS lymphoma since the mutation MYD88 L265P is highly predictive of this disease. However, whether the MYD88 L265P mutation may lead to other diseases outside of malignancy is not well understood. Here we describe two patients with the MYD88 L265P mutation in the CSF with no additional evidence of neoplastic disease but were found to have two distinct neurologic autoimmune conditions (anti-GFAP astrocytopathy and multiple sclerosis). These cases suggest this activating mutation may predispose certain patients to autoimmune conditions and may have future therapeutic implications.

Clinical Features and Diagnosis of Intramedullary Spinal Cord Abscess in Adults: A Systematic Review.

BACKGROUND AND OBJECTIVES: Intramedullary spinal cord abscess (ISCA) was described 200 years ago but remains poorly understood and is often mistaken for immune-mediated or neoplastic processes. We present a systematic review of ISCA in adults, describing the clinical presentation, diagnostic features, treatment strategies, and outcomes. METHODS: Database searches for intramedullary abscess were performed on April 15, 2019, and repeated on February 9, 2022, using PubMed and EMBASE with 2 unpublished cases also included. Publications were independently reviewed for inclusion by 2 authors followed by adjudication. Data were abstracted using an online form and then analyzed for predictors of disability. RESULTS: A total of 202 cases were included (median age 45 years [interquartile range 31-58]; 70% male). Thirty-one percent of those affected had no identified predisposing condition. The most common symptom was weakness (97%), and the median symptom duration before presentation was 10 days (interquartile range 5-42). An MRI showed restricted diffusion in 100% of 8 cases where performed and enhancement in 99% of 153 cases where performed. The most common organisms were Mycobacterium tuberculosis (29%), Streptococcus sp. (13%), and Staphylococcus sp. (10%). All patients received antimicrobial therapy; surgical drainage was performed in 65%. At follow-up (median 6 months), 12% had died, 69% were ambulatory, and 77% had improved compared with clinical nadir. Of those who underwent operative intervention, surgery within 24 hours of diagnosis was associated with an increased likelihood of being ambulatory at follow-up compared with surgery after 24 hours (odds ratio 4.44; 95% CI 1.26-15.61; p = 0.020). DISCUSSION: ISCA is important to consider in any patient presenting with acute-to-subacute, progressive myelopathy. Immunocompromise and typical signs of infection (e.g., fever) are often absent. Diffusion restriction and gadolinium enhancement on MRI seem to be sensitive. Antimicrobial therapy with surgical drainage is the most common therapeutic approach, but morbidity remains substantial. If performed, urgent surgery may be more beneficial.

Development of a Definition of Postacute Sequelae of SARS-CoV-2 Infection.

Importance: SARS-CoV-2 infection is associated with persistent, relapsing, or new symptoms or other health effects occurring after acute infection, termed postacute sequelae of SARS-CoV-2 infection (PASC), also known as long COVID. Characterizing PASC requires analysis of prospectively and uniformly collected data from diverse uninfected and infected individuals. Objective: To develop a definition of PASC using self-reported symptoms and describe PASC frequencies across cohorts, vaccination status, and number of infections. Design, Setting, and Participants: Prospective observational cohort study of adults with and without SARS-CoV-2 infection at 85 enrolling sites (hospitals, health centers, community organizations) located in 33 states plus Washington, DC, and Puerto Rico. Participants who were enrolled in the RECOVER adult cohort before April 10, 2023, completed a symptom survey 6 months or more after acute symptom onset or test date. Selection included population-based, volunteer, and convenience sampling. Exposure: SARS-CoV-2 infection. Main Outcomes and Measures: PASC and 44 participant-reported symptoms (with severity thresholds). Results: A total of 9764 participants (89% SARS-CoV-2 infected; 71% female; 16% Hispanic/Latino; 15% non-Hispanic Black; median age, 47 years [IQR, 35-60]) met selection criteria. Adjusted odds ratios were 1.5 or greater (infected vs uninfected participants) for 37 symptoms. Symptoms contributing to PASC score included postexertional malaise, fatigue, brain fog, dizziness, gastrointestinal symptoms, palpitations, changes in sexual desire or capacity, loss of or change in smell or taste, thirst, chronic cough, chest pain, and abnormal movements. Among 2231 participants first infected on or after December 1, 2021, and enrolled within 30 days of infection, 224 (10% [95% CI, 8.8%-11%]) were PASC positive at 6 months. Conclusions and Relevance: A definition of PASC was developed based on symptoms in a prospective cohort study. As a first step to providing a framework for other investigations, iterative refinement that further incorporates other clinical features is needed to support actionable definitions of PASC.

Preserved T cell but attenuated antibody response in MS patients on fingolimod and ocrelizumab following 2nd and 3rd SARS-CoV-2 mRNA vaccine.

Background: There is limited knowledge about T cell responses in patients with multiple sclerosis (MS) after 3 doses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine. Objectives: Assess the SARS-CoV-2 spike antibody and T cell responses in MS patients and healthy controls (HCs) after 2 doses (2-vax) and 3 doses (3-vax) of SARS-CoV-2 mRNA vaccination. Methods: We studied seroconversion rates and T cell responses by flow cytometry in HC and MS patients on fingolimod or ocrelizumab. Results: After 2-vax, 8/33 (24.2%) patients in ocrelizumab group, 5/7 (71.4%) in fingolimod group, and 29/29 (100%) in HC group (P = 5.7 × 10-11) seroconverted. After 3-vax, 9/22 (40.9%) patients in ocrelizumab group, 19/21 (90.5%) in fingolimod group, and 7/7 (100%) in HC group seroconverted (P = 0.0003). The percentage of SARS-CoV-2 peptide reactive total CD4+ T cells increased in HC and ocrelizumab group but not in fingolimod group after 2-vax and 3-vax (P < 0.0001). The percentage of IFNγ and TNFα producing total CD4+ and CD8+ T cells increased in fingolimod group as compared to HC and ocrelizumab group after 2-vax and 3-vax (P < 0.0001). Conclusions: MS patients on ocrelizumab and fingolimod had attenuated humoral responses, but preserved cytokine producing T cell responses compared to HCs after SARS-CoV-2 mRNA vaccination. Clinical Trials Registration: NCT05060354.

Fluorescein Angiography Findings in Susac Syndrome: A Multicenter Retrospective Case Series.

BACKGROUND: Susac syndrome is a vasculopathy, resulting in the classic triad of branch retinal artery occlusion (BRAO), inner ear ischemia, and brain ischemia. In this retrospective chart review, we characterize fluorescein angiography (FA) findings and other ancillary studies in Susac syndrome, including the appearance of persistent disease activity and the occurrence of new subclinical disease on FA. METHODS: This multicenter, retrospective case series was institutional review board-approved and included patients with the complete triad of Susac syndrome evaluated with FA, contrasted MRI of the brain, and audiometry from 2010 to 2020. The medical records were reviewed for these ancillary tests, along with demographics, symptoms, visual acuity, visual field defects, and findings on fundoscopy. Clinical relapse was defined as any objective evidence of disease activity during the follow-up period after initial induction of clinical quiescence. The main outcome measure was the sensitivity of ancillary testing, including FA, MRI, and audiometry, to detect relapse. RESULTS: Twenty of the 31 (64%) patients had the complete triad of brain, retinal, and vestibulocochlear involvement from Susac syndrome and were included. Median age at diagnosis was 43.5 years (range 21-63), and 14 (70%) were women. Hearing loss occurred in 20 (100%), encephalopathy in 13 (65%), vertigo in 15 (75%), and headaches in 19 (95%) throughout the course of follow-up. Median visual acuity at both onset and final visit was 20/20 in both eyes. Seventeen (85%) had BRAO at baseline, and 10 (50%) experienced subsequent BRAO during follow-up. FA revealed nonspecific leakage from previous arteriolar damage in 20 (100%), including in patients who were otherwise in remission. Of the 11 episodes of disease activity in which all testing modalities were performed, visual field testing/fundoscopy was abnormal in 4 (36.4%), MRI brain in 2 (18.2%), audiogram in 8 (72.7%), and FA in 9 (81.8%). CONCLUSIONS: New leakage on FA is the most sensitive marker of active disease. Persistent leakage represents previous damage, whereas new areas of leakage suggest ongoing disease activity that requires consideration of modifying immunosuppressive therapy.

Characteristics of Progressive Multifocal Leukoencephalopathy Associated With Sarcoidosis Without Therapeutic Immune Suppression.

Importance: Progressive multifocal leukoencephalopathy can occur in the context of systemic sarcoidosis (S-PML) in the absence of therapeutic immune suppression and can initially be mistaken for neurosarcoidosis or other complications of sarcoidosis. Earlier recognition of S-PML could lead to more effective treatment of the disease. Objective: To describe characteristics of patients with S-PML. Design, Setting, and Participants: For this case series, records from 8 academic medical centers in the United States were reviewed from 2004 to 2022. A systematic review of literature from 1955 to 2022 yielded data for additional patients. Included were patients with S-PML who were not receiving therapeutic immune suppression. The median follow-up time for patients who survived the acute range of illness was 19 months (range, 2-99). Data were analyzed in February 2023. Exposures: Sarcoidosis without active therapeutic immune suppression. Main Outcomes and Measures: Clinical, laboratory, and radiographic features of patients with S-PML. Results: Twenty-one patients with S-PML not receiving therapeutic immune suppression were included in this study, and data for 37 patients were collected from literature review. The median age of the 21 study patients was 56 years (range, 33-72), 4 patients (19%) were female, and 17 (81%) were male. The median age of the literature review patients was 49 years (range, 21-74); 12 of 34 patients (33%) with reported sex were female, and 22 (67%) were male. Nine of 21 study patients (43%) and 18 of 31 literature review patients (58%) had simultaneous presentation of systemic sarcoidosis and PML. Six of 14 study patients (43%) and 11 of 19 literature review patients (58%) had a CD4+ T-cell count greater than 200/µL. In 2 study patients, a systemic flare of sarcoidosis closely preceded S-PML development. Ten of 17 study patients (59%) and 21 of 35 literature review patients (60%) died during the acute phase of illness. No meaningful predictive differences were found between patients who survived S-PML and those who did not. Conclusions and Relevance: In this case series, patients with sarcoidosis developed PML in the absence of therapeutic immune suppression, and peripheral blood proxies of immune function were often only mildly abnormal. Systemic sarcoidosis flares may rarely herald the onset of S-PML. Clinicians should consider PML in any patient with sarcoidosis and new white matter lesions on brain magnetic resonance imaging.

Revisiting a Telencephalic Extent of the Ascending Reticular Activating System.

Is the cerebrum involved in its own activation to states of attention or arousal? "Telencephalon" is a term borrowed from embryology to identify not only the cerebral hemispheres of the forebrain, but also the basal forebrain. We review a generally undercited literature that describes nucleus basalis of Meynert, located within the substantia innominata of the ventrobasal forebrain, as a telencephalic extension of the ascending reticular activating formation. Although that formation's precise anatomical definition and localization have proven elusive over more than 70 years, a careful reading of sources reveals that there are histological features common to certain brainstem neurons and those of the nucleus basalis, and that a largely common dendritic architecture may be a morphological aspect that helps to define non-telencephalic structures of the ascending reticular activating formation (e.g., in brainstem) as well as those parts of the formation that are telencephalic and themselves responsible for cortical activation. We draw attention to a pattern of dendritic arborization described as "isodendritic," a uniform (isos-) branching in which distal dendrite branches are significantly longer than proximal ones. Isodendritic neurons also differ from other morphological types based on their heterogeneous, rather than specific afferentation. References reviewed here are consistent in their descriptions of histology, particularly in studies of locales rich in cholinergic neurons. We discuss the therapeutic implications of a basal forebrain site that may activate cortex. Interventions that specifically target nucleus basalis and, especially, the survival of its constituent neurons may benefit afflictions in which higher cortical function is compromised due to disturbed arousal or attentiveness, including not only coma and related syndromes, but also conditions colloquially described as states of cognitive "fog" or of "long-haul" mental compromise.

Quantifying the economic burden to patients of relapse events from neuromyelitis optica spectrum disorders: A cross-sectional survey.

We surveyed 103 adults (mean age 46 years; 85% female) with neuromyelitis optica spectrum disorders (NMOSD) through social media about their personal economic burden of NMOSD emergency department visits and hospitalizations ("relapse events"). The average number of relapse events over the prior 3 years was 5.3. Participants reported direct, out-of-pocket costs for 52% of events (mean cost per event 3326 USD, 95% CI [2378,4274]) and indirect costs (e.g., childcare) for 26% (mean cost per event 1907 USD, 95% CI [1159,2655]). Sixty-nine percent reported lost income due to hospital visits. Future work should identify and support subgroups with higher economic burden from NMOSD.

Neurologic disease activity in people with multiple sclerosis treated with immune checkpoint inhibitors.

BACKGROUND: There is concern that immune checkpoint inhibitors (ICPIs) can provoke relapses in people with multiple sclerosis (pwMS). OBJECTIVE: Analyze outcomes of pwMS who received ICPI treatment for malignancy. METHODS: We electronically identified pwMS who received ICPI treatment at Mass General Brigham hospital system. We retrospectively obtained information about patients' MS, cancer, treatment, and outcomes. RESULTS: Sixteen patients were identified with an average (standard deviation (SD)) age of 67.4 (11.9) years. Eleven (68.8%) had no relapses since MS diagnosis. None had MS relapses after ICPI treatment or new MS lesions. CONCLUSION: ICPI use was not associated with increased clinical disease activity in this cohort of older patients with inactive MS.

Humoral response to COVID-19 vaccination in MS patients on disease modifying therapy: Immune profiles and clinical outcomes.

BACKGROUND: Patients with multiple sclerosis (MS) on some disease modifying therapies (DMTs), particularly anti-CD20 and sphingosine-1-phosphate (S1P) modulators, are at increased risk of severe Coronavirus Disease 19 (COVID-19) and death. COVID-19 vaccinations are effective in preventing infection and severe disease, but humoral response to vaccination and outcomes of COVID-19 infection after vaccination in MS patients on DMTs remain less understood. METHODS: In this retrospective single-center study, patients enrolled in the CLIMB (Comprehensive Longitudinal Investigation of Multiple Sclerosis at Brigham and Women's Hospital) study and biorepository who had been vaccinated against COVID-19 and had SARS-CoV-2 spike antibody (anti-SARS-CoV-2 S Roche-Elecsys) testing were identified and compared to healthy controls. Demographic data, serum immune profiles including lymphocyte count, B-cell count, and immunoglobulins, and clinical outcome of COVID-19 infection were collected. RESULTS: 254 patients (73.2% female, mean (SD) age 52.9 (11.2) years) were identified. When controlling for age, time since vaccination, and vaccine type, patients on fingolimod, ocrelizumab, rituximab, mycophenolate mofetil, natalizumab and teriflunomide had significantly lower levels of spike antibodies compared to healthy controls (n = 34). Longer duration of treatment was associated with lower spike antibody levels in patients on anti-CD20 therapy (p = 0.016) and S1P modulators (p = 0.016) compared to healthy controls. In patients on anti-CD20 therapy, higher spike antibody levels were associated with higher CD20 cell count (p<0.001), and longer time since last anti-CD20 therapy infusion (p<0.001). 92.8% (13/14) vaccine responders (spike antibody titer >100 ug/dL) on anti-CD20 therapy demonstrated B-cell reconstitution (mean CD20 3.6%). Only 1 out of 86 patients with CD20 of 0% had a measurable spike antibody response to vaccination. During follow-up (mean 270 days), five patients were diagnosed with COVID-19 after vaccination (incidence 1.9%), all of whom had spike antibody < 20 ug/dL. No patients required ICU care or died. CONCLUSIONS: Patients on some DMTs demonstrate reduced humoral immunity after Sars-CoV-2 vaccination. Longer duration of anti-CD20 therapy and reduced CD20 cell count is associated with blunted humoral response to vaccination. CD20 reconstitution >0.1% appears necessary, but not always sufficient, for humoral response to vaccination. Breakthrough COVID-19 infection in our cohort of MS patients on DMT was higher than in population studies. We propose that adjustment of B-cell therapy administration to allow for B-cell reconstitution prior to vaccination should be considered.

Disease modifying therapy management of multiple sclerosis after stem cell therapies: A retrospective case series.

BACKGROUND: Stem cell therapies (SCT) have not received formal regulatory approval for the treatment of people with multiple sclerosis (PwMS), but PwMS may seek various options on their own accord. The current literature largely focuses on the efficacy and safety of SCT in PwMS in clinical trials, in particular autologous hematopoietic stem cell transplantation (aHSCT), in carefully selected participants. There is little reported on the MS disease modifying therapy (DMT) management of PwMS who choose to undergo SCT outside of these trials. METHODS: We identified PwMS from two academic centers who had MS diagnosis fulfilling 2017 McDonald criteria and received SCT (methodologies permitted: aHSCT, umbilical-derived mesenchymal stem cells and/or adipose-derived mesenchymal stem cells (AdMSC)), with the goal to treat MS, between 1/1/2015 and 11/30/2021. RESULTS: Nine PwMS (five females; age range at SCT treatment 25-69 years old; MS disease duration 1-12 years; six relapsing-remitting, three secondary progressive, one primary progressive) underwent a total of eleven SCTs (nine aHSCT, two AdMSC, one umbilical-derived MSC) with the goal to treat MS. Two of six PwMS who underwent SCT <10 years from MS diagnosis, and one of three PwMS who underwent stem cell therapies >10 years from MS diagnosis were clinically stable thereafter. An MS DMT was resumed in five PwMS afterwards, including rituximab, ocrelizumab, siponimod, and glatiramer acetate: one remained clinically stable, whereas four clinically progressed. Four PwMS remained off of a DMT: three were clinically stable, whereas one clinically progressed. All nine patients demonstrated radiographic stability by MRI after SCT. Only one met formal criteria to consider aHSCT for MS. CONCLUSIONS: We demonstrate the heterogeneous real-world experience of treating MS after patient-chosen experimental SCTs, detailing the range of DMT management in various patient circumstances. Limitations of our study include its small sample size and the variety of stem cell therapies received.

Cortical and Subcortical Dysmetabolism Are Dynamic Markers of Clinical Disability and Course in Anti-LGI1 Encephalitis.

BACKGROUND AND OBJECTIVES: This [18F]fluorodeoxyglucose (FDG) PET study evaluates the accuracy of semiquantitative measurement of putaminal hypermetabolism in identifying anti-leucine-rich, glioma-inactivated-1 (LGI1) protein autoimmune encephalitis (AE). In addition, the extent of brain dysmetabolism, their association with clinical outcomes, and longitudinal metabolic changes after immunotherapy in LGI1-AE are examined. METHODS: FDG-PET scans from 49 age-matched and sex-matched subjects (13 in LGI1-AE group, 15 in non-LGI1-AE group, 11 with Alzheimer disease [AD], and 10 negative controls [NCs]) and follow-up scans from 8 patients with LGI1 AE on a median 6 months after immunotherapy were analyzed. Putaminal standardized uptake value ratios (SUVRs) normalized to global brain (P-SUVRg), thalamus (P/Th), and midbrain (P/Mi) were evaluated for diagnostic accuracy. SUVRg was applied for all other analyses. RESULTS: P-SUVRg, P/Th, and P/Mi were higher in LGI1-AE group than in non-LGI1-AE group, AD group, and NCs (all p < 0.05). P/Mi and P-SUVRg differentiated LGI1-AE group robustly from other groups (areas under the curve 0.84-0.99). Mediotemporal lobe (MTL) SUVRg was increased in both LGI1-AE and non-LGI1-AE groups when compared with NCs (both p < 0.05). SUVRg was decreased in several frontoparietal regions and increased in pallidum, caudate, pons, olfactory, and inferior occipital gyrus in LGI1-AE group when compared with that in NCs (all p < 0.05). In LGI1-AE group, both MTL and putaminal hypermetabolism were reduced after immunotherapy. Normalization of regional cortical dysmetabolism associated with clinical improvement at the 6- and 20-month follow-up. DISCUSSION: Semiquantitative measurement of putaminal hypermetabolism with FDG-PET may be used to distinguish LGI1-AE from other pathologies. Metabolic abnormalities in LGI1-AE extend beyond putamen and MTL into other subcortical and cortical regions. FDG-PET may be used in evaluating disease evolution in LGI1-AE. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that semiquantitative measures of putaminal metabolism on PET can differentiate patients with LGI1-AE from patients without LGI1-AE, patients with AD, or NCs.

COVID-19 mRNA vaccination leading to CNS inflammation: a case series.

The availability of vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), provides hope towards mitigation of the coronavirus disease 2019 (COVID-19) pandemic. Vaccine safety and efficacy has not been established in individuals with chronic autoimmune diseases such as multiple sclerosis (MS). Anecdotal reports suggest that the vaccines may be associated with brain, spinal cord, peripheral nervous system, and cardiac inflammation. Based on the high morbidity and unpredictable course of COVID-19, and the need to achieve herd immunity, vaccination has been recommended for patients with MS. We report clinical and MRI features of seven individuals who received the Moderna (n = 3) or Pfizer (n = 4) SARS-CoV-2 mRNA vaccines. Within one to 21 days of either the first (n = 2) or second (n = 5) vaccine dose, these patients developed neurologic symptoms and MRI findings consistent with active CNS demyelination of the optic nerve, brain, and/or spinal cord. Symptoms included visual loss, dysmetria, gait instability, paresthesias, sphincter disturbance, and limb weakness. Age ranged from 24 to 64 (mean 39.1) years; five were woman (71.4%). The final diagnosis was exacerbation of known stable MS (n = 4, two were receiving disease-modifying therapy at the time of vaccination), new onset MS (n = 2), or new onset neuromyelitis optica (n = 1). All responded to corticosteroid (n = 7) or plasma exchange (n = 1) therapy, with five returning to baseline and two approaching baseline. Large prospective studies are required to further investigate any possible relationship between COVID-19 vaccines and acute CNS demyelination.

ACR Appropriateness Criteria® Suspected Spine Infection.

Spine infection is both a clinical and diagnostic imaging challenge due to its relatively indolent and nonspecific clinical presentation. The diagnosis of spine infection is based upon a combination of clinical suspicion, imaging evaluation and, when possible, microbiologic confirmation performed from blood cultures or image-guided percutaneous or open spine biopsy. With respect to the imaging evaluation of suspected spine infection, MRI without and with contrast of the affected spine segment is the initial diagnostic test of choice. As noncontrast MRI of the spine is often used in the evaluation of back or neck pain not responding to conservative medical management, it may show findings that are suggestive of infection, hence this procedure may also be considered in the evaluation of suspected spine infection. Nuclear medicine studies, including skeletal scintigraphy, gallium scan, and FDG-PET/CT, may be helpful in equivocal or select cases. Similarly, radiography and CT may be appropriate for assessing overall spinal stability, spine alignment, osseous integrity and, when present, the status of spine instrumentation or spine implants. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.