Targeted metabolomics identifies accurate CSF metabolite biomarkers for the differentiation between COVID-19 with neurological involvement and CNS infections with neurotropic viral pathogens.

BACKGROUND: COVID-19 is primarily considered a respiratory tract infection, but it can also affect the central nervous system (CNS), which can result in long-term sequelae. In contrast to CNS infections by classic neurotropic viruses, SARS-CoV-2 is usually not detected in cerebrospinal fluid (CSF) from patients with COVID-19 with neurological involvement (neuro-COVID), suggesting fundamental differences in pathogenesis. METHODS: To assess differences in CNS metabolism in neuro-COVID compared to CNS infections with classic neurotropic viruses, we applied a targeted metabolomic analysis of 630 metabolites to CSF from patients with (i) COVID-19 with neurological involvement [n = 16, comprising acute (n = 13) and post-COVID-19 (n = 3)], (ii) viral meningitis, encephalitis, or myelitis (n = 10) due to herpes simplex virus (n = 2), varicella zoster virus (n = 6), enterovirus (n = 1) and tick-borne encephalitis virus (n = 1), and (iii) aseptic neuroinflammation (meningitis, encephalitis, or myelitis) of unknown etiology (n = 21) as additional disease controls. RESULTS: Standard CSF parameters indicated absent or low neuroinflammation in neuro-COVID. Indeed, CSF cell count was low in neuro-COVID (median 1 cell/µL, range 0-12) and discriminated it accurately from viral CNS infections (AUC = 0.99) and aseptic neuroinflammation (AUC = 0.98). 32 CSF metabolites passed quality assessment and were included in the analysis. Concentrations of differentially abundant (fold change ≥|1.5|, FDR ≤ 0.05) metabolites were both higher (9 and 5 metabolites) and lower (2 metabolites) in neuro-COVID than in the other two groups. Concentrations of citrulline, ceramide (d18:1/18:0), and methionine were most significantly elevated in neuro-COVID. Remarkably, triglyceride TG(20:1_32:3) was much lower (mean fold change = 0.09 and 0.11) in neuro-COVID than in all viral CNS infections and most aseptic neuroinflammation samples, identifying it as highly accurate biomarker with AUC = 1 and 0.93, respectively. Across all samples, TG(20:1_32:3) concentration correlated only moderately with CSF cell count (ρ = 0.65), protein concentration (ρ = 0.64), and Q-albumin (ρ = 0.48), suggesting that its low levels in neuro-COVID CSF are only partially explained by less pronounced neuroinflammation. CONCLUSIONS: The results suggest that CNS metabolite responses in neuro-COVID differ fundamentally from viral CNS infections and aseptic neuroinflammation and may be used to discover accurate diagnostic biomarkers in CSF and to gain insights into differences in pathophysiology between neuro-COVID, viral CNS infections and aseptic neuroinflammation.

A devastating case of a Balamuthia mandrillaris pediatric brain infection.

Balamuthia mandrillaris is an amoeba that causes an uncommon but deadly encephalitis, referred to as granulomatous amoebic encephalitis (GAE). The highest incidence reported worldwide has occurred in America, and within the United States, it has been highest in the Southwest affecting predominantly children and young men of Hispanic ethnicity. Clinical presentation of GAE includes fever, headache, nausea, vomiting, lethargy, irritability, stiff neck, hallucinations, photophobia, and seizures. Our patient was a Hispanic male child living in Arizona. The patient presented at 3 years of age for severe encephalitis. Symptoms included difficulty with balance, gait, and sitting up and seizure-like activity. Initial CT showed an area of decreased density consistent with edema in the right frontal and left frontoparietal lobes. Rapid progression was seen on further imaging over the length of the patient's hospital stay revealing diffusion restriction, necrosis/blood products, edema, and hemorrhage. The patient expired three weeks after onset of symptoms and one week after admission to our institution. While there are multiple biochemical techniques that can test for B. mandrillaris, they are rarely employed for multiple reasons stemming from the rare occurrence of this infection. Because of the fatal nature of this infection, we propose (1) testing should be considered if a patient presents with progressing encephalitis on imaging and other pathogenic etiologies are ruled out and (2) the threshold to treat empirically should be low due to the fatal nature of the infection.

Acute Encephalitis During a SARS-CoV-2 Infection: A Case Report.

It was in December 2019 that the coronavirus causing COVID-19 was first detected in Wuhan, China. Although the primary clinical presentation is respiratory disease, an increasing number of reports worldwide have noted various neurological manifestations, such as acute encephalitis. We present a case of a 49-year-old female admitted with afebrile impaired consciousness, diagnosed with acute encephalitis and a severe infection of COVID-19. Clinical and radiological improvement was observed following treatment with corticosteroids.

Anti-LGI1 Autoimmune Encephalitis in a Patient with Rheumatoid Arthritis and MGUS.

Background: Anti-leucine-rich glioma inactivated 1 limbic encephalitis (anti-LGI1 LE) is one of the most frequent autoimmune encephalitis, commonly coexisting with other autoimmune diseases. Rheumatoid arthritis (RA) and monoclonal gammopathy of unknown significance (MGUS) are commonly associated with autoimmune phenomena. However, neither RA nor MGUS have been described in the literature to date as coexisting with anti-LGI1 LE. Case description: We present the case of anti-LGI1 LE in a male patient with rheumatoid arthritis, who was also found to have an MGUS. The patient was initially treated with corticosteroids and IV immunoglobulin. After a mild relapse, his treatment was complemented with rituximab, resulting in complete regression of the disease symptoms. Conclusions: Our report provides evidence for the coexistence of anti-LGI1 LE with RA and/or MGUS, thus extending the differential diagnosis of patients suffering with these disease entities that present with neuropsychiatric symptoms suggestive of encephalitis. Moreover, this case raises challenges on the management of the coexistence of these diseases, given the lack of therapeutic guidelines and their potential interaction on a pathophysiological and a clinical level. LEARNING POINTS: In a patient with known autoimmune or malignant background who presents with neuropsychiatric symptoms, after excluding infectious encephalitis or central nervous system involvement in the primary disease condition, autoimmune limbic encephalitis (LE) should also be considered.In a patient diagnosed with anti-LGI1 LE there should be an extensive check for coexisting occult pre-malignant conditions, even for months after disease presentation.Clinical management and treatment options of anti-LGI1 LE when coexisting with other autoimmune or pre-malignant conditions can be challenging; thus, more research is needed towards that direction.

Anti-CRMP2 antibody induces anxiety-like behavior and increases pyramidal neuron excitability in mice.

BACKGROUND: We have previously identified auto-antibody (Ab) to collapsin response mediator protein 2 (CRMP2) in patients with encephalitis. The present study aims to evaluate the pathogenic effects of anti-CRMP2 Ab. METHODS: Recombinant CRMP2 protein was injected subcutaneously into mice to establish an active immune mouse model with anti-CRMP2 Ab. Behavioral assessments, histopathological staining, and electrophysiological testing were performed to identify any pathogenic changes. RESULTS: The mice exhibited signs of impaired motor coordination four weeks post-immunization of CRMP2 protein. Moreover, CRMP2 immunized mice for eight weeks showed anxiety-like behaviors indicating by tests of open field and the elevated plus maze. After incubating the CA1 region of hippocampal brain section with the sera from CRMP2 immunized mice, the whole-cell path-clamp recordings showed increased excitability of pyramidal neurons. However, no obvious inflammation and infiltration of immune cells were observed by histopathological analysis. Western blot showed that the phosphorylation levels of CRMP2-Thr514 and -Ser522 were not affected. CONCLUSION: In an active immunization model with CRMP2 protein, impaired coordination and anxiety-like behaviors were observed. Also, anti-CRMP2 Abs containing sera heightened the excitability of hippocampal pyramidal neurons in vitro, which imply the pathogenic effects of anti-CRMP2 Ab.

Neuropsychiatric manifestations of anti-N-methyl-D-aspartate receptor encephalitis in a 14-year-old female: A case report.

Key Clinical Message: This case underscores the critical importance of timely recognition and management of NMDAR encephalitis in adolescents to mitigate potential long-term sequelae. If a pediatric patient presents with suspected viral encephalitis, autoimmune etiology must be excluded via cerebrospinal fluid antibody assay to guide appropriate immunosuppressive therapy, and improve patient outcomes. Abstract: Autoimmune encephalitis particularly involving the n-methyl-d-aspartate receptor (NMDAR) is recognized as a rare cause of acute encephalopathy in pediatric patients. The following case is of a 14-year-old female diagnosed with anti-NMDAR encephalitis who initially presented with fever, episodic convulsions, and loss of consciousness. She subsequently developed right-sided body weakness, expressive aphasia, and visual hallucinations. Clinical examination revealed prominent neuropsychiatric manifestations such as altered sensorium, motor deficits, hallucinations, and visual disturbances. Cerebello-bulbar signs were not appreciable in this particular case. She was treated for viral encephalitis but showed no improvement. Laboratory investigations revealed the presence of NMDAR antibodies in the cerebrospinal fluid confirming the diagnosis of autoimmune etiology. The patient demonstrated notable improvement following immunosuppressive treatment.

Recurrent COVID-19-related psychotic disorder with neuro-immuno-endocrine dysfunction as a possible underlying mechanism: A case report from China.

Background: SARS-CoV-2, first identified in Wuhan, China, in December 2019, has been gradually spreading worldwide since 2020. The relationship between SARS-CoV-2 infection and psychotic disorders has received much attention, and several studies have described the direct/indirect mechanisms of its effects on the brain, but no mechanism has been found to explain recurrent episodes of COVID-19-related psychotic symptoms. Case: We report the case of an 18-year-old female patient with no family or personal psychotic disorder history with multiple hospital admissions with symptoms such as disorganized speech and behavior, hyperactivity, restlessness, and impulsive aggression during the COVID-19 recovery period. Relevant tests revealed longitudinal changes such as persistent IL-6 and IL-10 elevation, abnormal discharges on EEG, and brain and hippocampal MRI abnormal signals. The patient was treated with antipsychotics, MECT, combination therapy of hormones and antivirals, then discharged after multiple treatment rounds. Conclusion: The case presented here outlines the possibility that the COVID-19 recovery period may be a critical period for acute psychotic episodes and that the patient's recurrent psychotic symptoms may be associated with neuro-immuno-endocrine dysfunction mediated by sustained cytokine synthesis, further causing structural and functional brain damage. Routine psychiatric evaluation and related screening should be performed at all stages of the illness to better identify, prevent, and effectively intervene in psychiatric disorders following COVID-19. Because many outcomes require long-term assessment, a clearer understanding of the impact of the COVID-19 epidemic on mental health is likely to emerge in the future.

Disseminated herpes zoster with varicella encephalitis and pneumonia following ChAdOx1 nCoV-19 (AZD1222) vaccine in an immunocompetent male-a case report.

A middle-aged gentleman, presented to our outpatient department with painful skin lesions suggestive of disseminated herpes zoster. Further examination revealed bilateral cerebellar signs. He had a history of receiving a third dose of AZD1222 vaccine fourteen days prior to the onset of skin lesions but had no other significant medical history. The patient was also evaluated for retroviral infection and other immunodeficient states, workup for which were negative. The patient was initially treated with intravenous acyclovir 7.5 mg/kg/q8H; however, the patient developed varicella encephalitis on treatment, which was followed by pneumonia and haemorrhagic cystitis. Subsequently, treatment was started with acyclovir 10 mg/kg/q8H for 14 days, followed by valacyclovir for eight days, following which there was near-complete resolution of symptoms with the persistence of minimal rigidity. Although there have been several reports of herpes zoster following SARS-CoV-2 vaccination, we found few reports of varicella zoster with systemic manifestations following ChAdOx1 nCoV-19 (AZD1222) vaccination. This case highlights the importance of considering varicella zoster reactivation in a patient presenting with encephalitis or pneumonia post SARS-CoV-2 vaccination.

Varicella Zoster Virus Vasculopathy: An Under-Recognized Entity.

Varicella zoster virus (VZV) vasculopathy is a rare yet potentially severe neurological manifestation resulting from VZV reactivation, primarily affecting immunocompromised individuals. We present a case report of a 61-year-old male with VZV vasculopathy who initially presented with herpes zoster ophthalmicus, subsequently complicated by meningoencephalitis and an acute infarct in the territory of the left middle cerebral artery (MCA). Imaging revealed acute and chronic infarcts in the capsuloganglionic regions, accompanied by thickening and enhancement of the left MCA wall. Treatment involved a 14-day course of intravenous acyclovir, supplemented with oral prednisolone, resulting in modest clinical improvement. VZV vasculopathy represents an infrequently acknowledged neurological syndrome, particularly prevalent among immunocompromised individuals. Early recognition and appropriate intervention offer promise in ameliorating outcomes for affected patients. This case emphasizes the importance of including VZV vasculopathy in the differential diagnosis of neurological deficits, especially within high-risk populations.

Changes in cerebrospinal fluid proteome of patients with tick-borne encephalitis.

Tick-borne encephalitis (TBE) is one of the main diseases transmitted by ticks, the incidence of which is increasing. Moreover, its diagnosis and therapy are often long and difficult according to nonspecific symptoms and complex etiology. This study aimed to observe changes in the proteome of cerebrospinal fluid from TBE patients. Cerebrospinal fluid (CSF) of TBE patients (n = 20) and healthy individuals (n = 10) was analyzed using a proteomic approach (QExactiveHF-Orbitrap mass spectrometer) and zymography. Obtained results show that in CSF of TBE patients, the top-upregulated proteins are involved in pro-inflammatory reaction (interleukins), as well as antioxidant/protective response (peroxiredoxins, heat shock proteins). Moreover, changes in the proteome of CSF are not only the result of this disease development, but they can also be an indicator of its course. This mainly applies to proteins involved in proteolysis including serpins and metalloproteinases, whose activity is proportional to the length of patients' convalescence. The obtained proteomic data strongly direct attention to the changes caused by the development of TBE to antioxidant, pro-inflammatory, and proteolytic proteins, knowledge about which can significantly contribute to faster and more accurate diagnosis of various clinical forms of TBE.

Reversible splenial lesion syndrome in Anti-N-methyl-D-aspartate receptor encephalitis.

Here we described an 18-year-old woman who were initially misdiagnosed as psychiatric disorders in a psychiatric institution. She was transferred to our neurological ward because of impaired consciousness. Neuronal antibody testing confirmed the diagnosis of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. Cerebral magnetic resonance imaging (MRI) revealed a concomitant disorder named reversible splenial lesion syndrome (RESLES). After administration of combined immunotherapy, the patient recovered completely 3 months after discharge. To our knowledge, co-occurrence of RESLES and anti-NMDAR encephalitis was only described in two patients with teratoma and we provide another case without teratoma. We highlight that anti-NMDAR antibodies can be added to the multiple causes of RESLES. It is therefore imperative for clinicians to detect anti-neuronal antibodies in patients with RESLES to avoid missed diagnosis.

Clinical characteristics, immunological alteration and distinction of MOG-IgG-associated disorders and GFAP-IgG-associated disorders.

The classification of autoimmune encephalitis (AE) is based on the presence of different types of antibodies. Currently, the clinical manifestations and treatment regimens of patients with all types of AE exhibit similarities. However, the presence of immunological distinctions among different types of AE remains uncertain. In this study, we prospectively collected clinical data, as well as blood and cerebrospinal fluid (CSF) samples from patients diagnosed with MOG antibody-associated disease (MOGAD) or GFAP astrocytopathy (GFAP-A), in order to assess changes in inflammatory biomarkers such as immunoglobulin oligoclonal bands, cytokines in serum and CSF, as well as peripheral blood lymphocyte subtypes within different subsets. To further distinguish the immune response in patients with MOGAD and GFAP-A from that of healthy individuals, we prospectively recruited 20 hospitalized patients diagnosed with AE. Among them, 15 (75%) tested positive for MOG antibodies, 4 (20%) tested positive for GFAP antibodies, and 1 (5%) tested positive for both MOG and GFAP antibodies. These patients were then followed up for a period of 18 months. Compared to healthy controls (HC), AE patients exhibited elevated levels of MIP-1beta, SDF-1alpha, IL-12p70, IL-5, IL-1RA, IL-8 and decreased levels of IL-23, IL-31, IFN-alpha, IL-7, TNF-beta and TNF-alpha in serum. The CSF of AE patients showed increased levels of IL-1RA, IL-6 and IL-2 while decreased levels of RANTES, IL-18,IL-7,TNF-beta,TNF-alpha,RANTES,Eotaxin,and IL-9. The level of MCP-1 in the CSF of GFAP-A patients was found to be lower compared to that of MOGAD patients, while RANTES levels were higher. And the levels of IL-17A, Eotaxin, GRO-alpha, IL-8, IL-1beta, MIP-1beta were higher in the CSF of patients with epilepsy. The presence of intrathecal immune responses is also observed in patients with spinal muscular atrophy (SMA). However, no biomarker was found to be associated with disease severity in patients with AE. Among the 17 patients, recovery was observed, while 2 patients experienced persistent symptoms after an 18-month follow-up period. Additionally, within one year of onset, 8 patients had a single recurrence. Therefore, the immunological profiles of MOGAD and GFAP-A patients differ from those of normal individuals, and the alterations in cytokine levels may also exhibit a causal association with the clinical presentations, such as seizure.

A rare pediatric patient of anti-IgLON5 encephalitis with epileptic seizures as the first symptom.

BACKGROUND: Anti-IgLON5 encephalitis was a rare neurological and heterogeneous disorder, which was mainly found in adults. Epileptic seizures related to anti-IgLON5 disease were rarely reported. METHODS: Neural antibodies associated with autoimmune encephalitis in serum and cerebrospinal fluid (CSF) were tested using cell-based assays (CBA) with immunofluorescence double staining. The antibodies in serum were further confirmed by tissue-based assay (TBA) with rat brain and kidney tissue. RESULTS: We reported a pediatric case presented with epileptic seizures, cognitive impairments, and sleep disorders. Autoantibody screening showed anti-IgLON5 antibody IgG (1:100+) and anti-NMDAR antibody IgG (1:10+) in the serum. She was diagnosed as anti-IgLON5 encephalitis. Her conditions improved rapidly by treated with intravenous immunoglobulin and high dose intravenous methylprednisolone. CONCLUSION: We described the second pediatric case with anti-IgLON5 encephalitis, who was also the first presented with epileptic seizures as the initial presentation. Anti-IgLON5 encephalitis might have mild manifestations. For patients with new onset seizures associated with cognitive impairments and sleep disturbances, anti-IgLON5 antibody should be tested as early, even in children.

Differentiating rhythmic high-amplitude delta with superimposed (poly) spikes from extreme delta brushes: limitations of standardized nomenclature and implications for patient management.

BACKGROUND: Following the standardized nomenclature proposed by the American Clinical Neurophysiology Society (ACNS), rhythmic high-amplitude delta activity with superimposed spikes (RHADS) can be reported as an extreme delta brush (EDB). The clinical implications of similar electrographic patterns being reported as RHADS versus EDB are important to highlight. We aim to review the electrographic characteristics of RHADS, evaluate whether RHADS is seen in other neurological disorders, and identify the similar and unique characteristics between RHADS and EDB to ultimately determine the most accurate way to differentiate and report these patterns. We believe that the differentiation of RHADS and EDB is important as there is a vast difference in the diagnostic approach and the medical management of associated underlying etiologies. DATA SOURCE: We conducted an extensive search on MEDLINE and Pubmed utilizing various combinations of keywords. Searching for "gamma polymerase and EEG", or "RHADS" or "Alpers syndrome and EEG" or "EEG" AND "Alpers-Huttenlocher syndrome". RESULTS: Three articles were found to be focused on the description of "RHADS" pattern in Alpers Syndrome. No publication to date were found when searching for the terms "EDB" AND "children", AND "infant" AND "adolescent" excluding "encephalitis" and "neonate". Although RHADS and EDB appear as similar EEG patterns, meticulous analysis can differentiate them. RHADS is not exclusive to patients with Alpers-Huttenlocher syndrome and may manifest in regions beyond the posterior head region. Reactivity to eye-opening and response to anesthesia can be two other elements that help in the differentiation of these patterns. CONCLUSION: RHADS is not exclusive to patients with AHS and may manifest in regions beyond the posterior head region. Reactivity to eye-opening and response to anesthesia are features that help in the differentiation of these patterns.

The spectrum of anti-GQ1B antibody syndrome: beyond Miller Fisher syndrome and Bickerstaff brainstem encephalitis.

INTRODUCTION: Since the initial identification of Miller Fisher syndrome (MFS) and Bickerstaff brainstem encephalitis (BBE),significant milestones have been achieved in understanding these diseases.Discoveries of common serum antibodies (IgG anti-GQ1b), antecedent infections, neurophysiological data, andneuroimaging suggested a shared autoimmune pathogenetic mechanism rather than distinct pathogenesis, leadingto the hypothesis that both diseases are part of a unified syndrome, termed "Fisher-Bickerstaff syndrome". The subsequent identification of atypical anti-GQ1b-positive forms expanded the classification to a broader condition known as "Anti-GQ1b-Antibody syndrome". METHODS: An exhaustive literature review was conducted, analyzing a substantial body of research spanning from the initialdescriptions of the syndrome's components to recent developments in diagnostic classification and researchperspectives. RESULTS: Anti-GQ1b syndrome encompasses a continuous spectrum of conditions defined by a common serological profilewith varying degrees of peripheral (PNS) and central nervous system (CNS) involvement. MFS and BBE represent theopposite ends of this spectrum, with MFS primarily affecting the PNS and BBE predominantly involving the CNS.Recently identified atypical forms, such as acute ophthalmoparesis, acute ataxic neuropathy withoutophthalmoparesis, Guillain-Barré syndrome (GBS) with ophthalmoparesis, MFS-GBS and BBE-GBS overlap syndromes,have broadened this spectrum. CONCLUSION: This work aims to provide an extensive, detailed, and updated overview of all aspects of the anti-GQ1b syndromewith the intention of serving as a stepping stone for further shaping thereof. Special attention was given to therecently identified atypical forms, underscoring their significance in redefining the boundaries of the syndrome.

An elderly case of paraneoplastic anti-NMDA receptor encephalitis associated with large cell neuroendocrine carcinoma of the lung.

BACKGROUND: Recent studies have suggested that N-methyl-D-aspartate (NMDA) receptors are involved in the cell proliferation in several tumors. However, there have been no reports demonstrating the expression of NR1 subunit of the NMDA receptor in large cell neuroendocrine carcinoma (LCNEC). CASE PRESENTATION: Here, we report the first elderly case of paraneoplastic anti-NMDA receptor encephalitis associated with LCNEC of the lung with NR1 expression. Of note, NR1 subunit expression in the tumor cells of the present case was confirmed by immunohistochemistry (IHC). Radiation therapy and immunotherapies, such as corticosteroids and intravenous immunoglobulin (IVIG), shrank the tumors and improved neurological symptoms in the present case. Additionally, we also confirmed the expression of NR1 in the tumor cells obtained from three other cases with LCNEC of the lung at our hospital by IHC. CONCLUSION: Our IHC results indicate that LCNEC generally expresses NR1 subunit and NMDA receptor may be involved in the tumor development and growth.

Current Mycoplasma pneumoniae outbreak: Don't forget its role in Bickerstaff encephalitis.

Mycoplasma pneumoniae is a common cause of community-acquired pneumonia in children and young adults. It is responsible of a broad array of extrapulmonary manifestations, the most severe affecting the central nervous system. We report a challenging diagnosis of macrolide-resistant M. pneumoniae-induced Bickerstaff encephalitis in a 16-year-old man.

The clinical and predictive value of 18F-FDG PET/CT metabolic patterns in a clinical Chinese cohort with autoimmune encephalitis.

AIMS: To investigate the diagnostic and predictive role of 18F-FDG PET/CT in patients with autoimmune encephalitis (AE) as a whole group. METHODS: Thrty-five patients (20 females and 15 males) with AE were recruited. A voxel-to-voxel semi-quantitative analysis based on SPM12 was used to analyze 18F-FDG PET/CT imaging data compared to healthy controls. Further comparison was made in different prognostic groups categorized by modified Rankin Scale (mRS). RESULTS: In total, 24 patients (68.6%) were tested positive neuronal antibodies in serum and/or CSF. Psychiatric symptoms and seizure attacks were major clinical symptoms. In the acute stage, 13 patients (37.1%) demonstrated abnormal brain MRI results, while 33 (94.3%) presented abnormal metabolism patterns. 18F-FDG PET/CT was more sensitive than MRI (p < 0.05). Patients with AE mainly presented mixed metabolism patterns compared to the matched controls, demonstrating hypermetabolism mainly in the cerebellum, BG, MTL, brainstem, insula, middle frontal gyrus, and relatively hypometabolism in the frontal cortex, occipital cortex, temporal gyrus, right parietal gyrus, left cingulate gyrus (p < 0.05, FWE corrected). After a median follow-up of 26 months, the multivariable analysis identified a decreased level of consciousness as an independent risk factor associated with poor outcome of AE (HR = 3.591, p = 0.016). Meanwhile, decreased metabolism of right superior frontal gyrus along with increased metabolism of the middle and upper brainstem was more evident in patients with poor outcome (p < 0.001, uncorrected). CONCLUSION: 18F-FDG PET/CT was more sensitive than MRI to detect neuroimaging abnormalities of AE. A mixed metabolic pattern, characterized by large areas of cortical hypometabolism with focal hypermetabolism was a general metabolic pattern. Decreased metabolism of right superior frontal gyrus with increased metabolism of the middle and upper brainstem may predict poor long-term prognosis of AE.

Novel diagnostic and prognostic approach for rapidly progressive dementias: Indicators based on amyloid/tau/neurodegeneration (ATN) framework.

AIMS: Apply established cerebrospinal fluid (CSF) and serum biomarkers and novel combined indicators based on the amyloid/tau/neurodegeneration (ATN) framework to improve diagnostic and prognostic power in patients with rapidly progressive dementias (RPDs). METHODS: CSF and serum biomarkers of Alzheimer's disease (AD) common neuropathology including Aß42, Aß40, p-Tau, and t-Tau were measured in cognitively normal (CN) controls (n = 33) and three RPD groups with rapidly progressive AD (rpAD, n = 23), autoimmune encephalitis (AE, n = 25), and Creutzfeldt-Jakob disease (CJD, n = 28). Logistic regression and multiple linear regression were used for producing combined indicators and prognostic assessment, respectively, including A&T, A&N, T&N, A&T&N, etc. RESULTS: Combined diagnostic indicator with A&T&N had the potential for differentiating AE from other types of RPDs, identifying 62.51% and 75% of AE subjects based on CSF and serum samples, respectively, compared to 39.13% and 37.5% when using autoantibodies. CSF t-Tau was associated with survival in the CJD group (adjusted R-Square = 0.16, p = 0.02), and its prognosis value improved when using combined predictors based on the ATN framework (adjusted R-Square = 0.273, p = 0.014). CONCLUSION: Combined indicators based on the ATN framework provide a novel perspective for establishing biomarkers for early recognition of RPDs due to treatment-responsive causes.

Severe Relapsing Autoimmune Encephalitis with GABAA Receptor, Titin, and AchR Antibodies in a Patient with Thymoma: A Case Report.

Introduction: We report a challenging case of autoimmune encephalitis in a patient with a thymoma harboring titin and acetylcholine receptor antibodies, who experienced multiple relapses despite thymectomy and aggressive first-line immunotherapy, and for whom GABAA receptor antibodies were ultimately identified. Case Presentation: This 40-year-old man presented with headaches, weakness, diplopia, hearing loss, and seizures progressing to status epilepticus. Brain MRI showed multifocal cortical and subcortical T2/fluid attenuated inversion recovery hyperintense lesions without enhancement. Initial neural antibody testing identified only acetylcholine receptor and titin antibodies. He presented multiple severe relapses despite complete thymoma resection, intravenous methylprednisolone with immunoglobulins or plasmapheresis, and mycophenolate mofetil. Second-line immunotherapy with rituximab was successful to alleviate symptoms and normalize the EEG and MRI after identification of anti-GABAA receptor antibodies on more comprehensive neural antibody testing for autoimmune encephalitis. Conclusion: This case demonstrates the complexity and importance of identifying pathogenic antibodies and selecting 2nd line treatment accordingly in patients with autoimmune encephalitis when multiple antibodies coexist. Despite tumor resection, aggressive immunotherapy may be needed to prevent further deterioration in anti-GABAA receptor encephalitis.