Case Of Autoimmune Encephalitis Research Articles

Long-Term Outcomes in Antibody-Negative Autoimmune Encephalitis: A Retrospective Study.

To characterize the long-term outcomes of patients with "possible only" or "probable" autoimmune encephalitis (AE). Despite comprising one-third of AE cases, antibody-negative cases lacking typical AE-defining features are understudied. We conducted a retrospective analysis of adult patients evaluated at a tertiary center neuroimmunology practice from 2006 to 2020, meeting diagnostic criteria for "possible only" or "probable but antibody-negative" AE, with at least one year of follow-up. All patients underwent neural antibody testing. Forty-five patients (median age, 61 years [range, 20-88]; female, 21 [47%]) were included, with a median follow-up of 36 months (range, 12-174). A change in diagnosis was noted in six additional patients, who were excluded from further analysis, with only two receiving a non-autoimmune diagnosis during follow-up. The majority (41/45 [91%]) presented with significant disability (modified Rankin Scale [mRS] ≥3) at baseline. CSF was inflammatory in 20/44 (45%) and MRI was abnormal in 21/45 (47%). Unclassified neural-specific IgG staining on tissue-based assay was detected in five (11%). Two cases (4%) had a paraneoplastic cause. The median time from onset to immunotherapy initiation was two months (range, 0-21), resulting in at least partial improvement in all 44 (98%) treated cases. Clinical relapses occurred in 14/45 (31%). At last follow-up, the most common symptoms were memory dysfunction (31/45 [69%]), attention deficits (17/45 [38%]), gait instability (13/45 [29%]), and visuospatial dysfunction (10/45 [22%]). Most patients achieved independence (median mRS, 2 [range, 0-6]); however, 11 patients had poor neurological outcome (mRS ≥3). Higher mRS score and gait assistance requirement at three months were predictive of poor outcome (P ≤0.01). Despite significant disability at initial stages, patients with antibody-negative but clinically presumed AE show potential for improvement with immunotherapy, highlighting the importance of early intervention. Early functional status and gait assistance requirements may assist in predicting long-term prognosis.

Long-term outcomes in antibody-negative autoimmune encephalitis: a retrospective study.

Despite constituting one-third of suspected autoimmune encephalitis (AE) patients, antibody-negative cases without typical AE features are understudied. We aim to characterize the clinical phenotypes and long-term outcomes of "possible only" and "probable" AE cases. We conducted a retrospective analysis of adult patients evaluated at Mayo Clinic's Autoimmune Neurology Clinic (01/01/2006-12/31/2020), meeting diagnostic criteria for "possible only" or "probable but antibody-negative" AE, with ≥ 1year of follow-up. All patients underwent neural antibody testing. Among fifty-one patients, six had a change in diagnosis (non-autoimmune, 2) and were excluded from further analysis. Forty-five patients were analyzed [median age, 61years (range 20-88); female, 21 (47%); median follow-up, 36months (range 12-174)]. A nadir modified Rankin Scale (mRS) ≥ 3 was recorded in 41/45 (91%). CSF was inflammatory in 20/44 (45%) and MRI had encephalitic changes in 21/45 (47%). Unclassified neural-specific IgG staining on tissue-based assay was detected in five (11%). Two patients (4%) had paraneoplastic causation. Relapses (> 3months from onset) were noted in 14 (31%). Memory dysfunction (69%), attention deficits (38%), and gait instability (29%) were the most frequent at the last follow-up. Most patients (76%) were independent at the last follow-up and only two required an assistive device to ambulate; 11 patients (24%) had poor neurological outcome (mRS ≥ 3). Higher mRS score and gait assistance requirement at 3months were predictive of poor outcome (P ≤ 0.01). Despite significant disability at initial disease stages, most antibody-negative AE patients regain independent functioning. Early functional status and gait assistance requirements may predict long-term prognosis.

Two Cases of Autoimmune Encephalitis with Multiple Anti-neuronal Antibodies

Autoimmune encephalitis (AE) can arise from various etiologies and present with complex clinical manifestations, especially in cases involving multiple anti-neuronal antibodies. This report presents two cases of AE with multiple anti-neuronal antibodies admitted to Ningbo Medical Center Li Huili Hospital on October 9, 2020, and March 12, 2024. Case 1 is a 15-year-old boy with positive anti-N-methyl-D-aspartate receptor (NMDAR) and anti-metabotropic glutamate receptor 5 (mGluR5) antibodies in his serum and cerebrospinal fluid (CSF). Case 2 is a 14-year-old boy with positive NMDAR and myelin oligodendrocyte glycoprotein (MOG) antibodies in his CSF. Patients with AE who have multiple anti-neuronal antibodies present significant diagnostic and therapeutic challenges, warranting close clinical attention.

Spinal Cord Involvement in Children with Acquired Demyelinating Syndromes: A Single Centre Study

Abstract Background Myelitis may be the first presentation of relapsing acquired demyelinating syndromes (ADS) such as neuromyelitis optica (NMO) or multiple sclerosis (MS) and in association with connective tissue diseases. It may also occur in the context of acute disseminated encephalomyelitis (ADEM). Early recognition of myelitis in these disorders will allow better management plan including theprognosis. Objective To evaluate the frequency of myelitis among children with acquired demyelinating neurological diseases, and the variability of clinical features, neuroimaging findings and treatments given. Methods A pilot observational study with both retrospective and prospective components was conducted on children and adolescents fulfilling the diagnostic criteria for any of the acquired demyelination syndromes admitted inChildren’s Hospital, Ain Shams University whose ages were below 18 years during the period from July 2020 to February 2022. Results Forty-three children were included in our study with mean (SD)age of onset 7.63 (4.28) years. The most common diagnosis was ADEM (n (%) =20 (46.5%), followed by transverse myelitis (TM) (n (%) =11 (25.6%) and NMO (n (%) =7(16.3%). Progression to develop encephalopathy was recorded in 55.8%of cases (100% of ADEM and autoimmune encephalitis (AE) cases). Seizures developed in 23.3% of cases (35% of ADEM, 50% of AE and 14.29% of NMO cases). MRI brain abnormalities were observed in 76.7% of cases (100% of ADEM, NMO, AE and MS cases), and abnormalities of MRI spine were seen in 59% of cases (100% of TM and MS cases, 85.7% of NMO, 33.3% of AE and 23.5% of ADEM cases). Spinal cord affection was most commonly cervical(86.9%) and mostly short segment. All cases received pulsed methylprednisolone therapy, while intravenous immunoglobulins (IVIG) were used in 32.5% of cases and plasmapheresis in 13.9% of cases as a stepwise approach. Nearly half of the cases (53.5%) had monophasic illnesses without the need for long term therapy. Conclusion Spinal cord involvement is frequently observed in childhood acute demyelinating syndromes, and is most commonly cervical and short-segment. MRI spine should be regarded as a sensitive tool for diagnosis of myelitis in the context of ADEM and MS. MRI Brain is a sensitive tool accounting forfindings in 100% of ADEM, NMO, AE and MS cases. Patients with ADEM and AE has higher risk to develop encephalopathy and seizures unlike TM, NMO and MS patients.

Prediction of Seropositivity in Suspected Autoimmune Encephalitis by Use of Radiomics: A Radiological Proof-of-Concept Study.

In this study, we sought to evaluate the capabilities of radiomics and machine learning in predicting seropositivity in patients with suspected autoimmune encephalitis (AE) from MR images obtained at symptom onset. In 83 patients diagnosed with AE between 2011 and 2022, manual bilateral segmentation of the amygdala was performed on pre-contrast T2 images using 3D Slicer open-source software. Our sample of 83 patients contained 43 seropositive and 40 seronegative AE cases. Images were obtained at our tertiary care center and at various secondary care centers in North Rhine-Westphalia, Germany. The sample was randomly split into training data and independent test data. A total of 107 radiomic features were extracted from bilateral regions of interest (ROIs). Automated machine learning (AutoML) was used to identify the most promising machine learning algorithms. Feature selection was performed using recursive feature elimination (RFE) and based on the determination of the most important features. Selected features were used to train various machine learning algorithms on 100 different data partitions. Performance was subsequently evaluated on independent test data. Our radiomics approach was able to predict the presence of autoantibodies in the independent test samples with a mean AUC of 0.90, a mean accuracy of 0.83, a mean sensitivity of 0.84 and a mean specificity of 0.82, with Lasso regression models yielding the most promising results. These results indicate that radiomics-based machine learning could be a promising tool in predicting the presence of autoantibodies in suspected AE patients. Given the implications of seropositivity for definitive diagnosis of suspected AE cases, this may expedite diagnostic workup even before results from specialized laboratory testing can be obtained. Furthermore, in conjunction with recent publications, our results indicate that characterization of AE subtypes by use of radiomics may become possible in the future, potentially allowing physicians to tailor treatment in the spirit of personalized medicine even before laboratory workup is completed.

Antibody-positive autoimmune encephalitis and paraneoplastic neurological syndrome: A Swedish case series.

This study aimed to explore the clinical characteristics and temporal disease course of patients with autoimmune encephalitis (AE) and paraneoplastic neurological syndrome (PNS) in Sweden. Thirty-seven antibody-positive AE and PNS cases were identified in the Healthcare region Mid Sweden between 2015 and 2019. Clinical data were collected through a retrospective review of electronic health records. Patients were divided into three subgroups based on antibody type: neuronal surface antibodies (NSAbs), onconeural antibodies, and anti-GAD65 antibodies. Nineteen patients had NSAbs, 11 onconeural antibodies, and seven anti-GAD65 antibodies. Anti-LGI1 and anti-NMDAR were the most frequently detected NSAbs, with anti-NMDAR cases having an older-than-expected age distribution (median age 40, range 17-72). Only 11 of 32 (30%) of patients had findings suggesting encephalitis on initial MRI, but 28 of 31 (90%) had pathological findings on initial cerebrospinal fluid analysis. All patients but one had abnormal EEG findings. Median time to immunotherapy was comparable among the three subgroups, whereas patients with anti-LGI1, anti-CASPR2, and anti-IgLON5 had an eightfold longer time to immunotherapy than anti-NMDAR and anti-GABA-B (p=.0016). There was a seasonal variation in onset for patients with non-tumor-related NSAbs and anti-GAD65 antibodies, with most patients (72%) falling ill in spring or summer. Swedish patients with AE and PNS had similar clinical characteristics as previously described cohorts from other geographical regions except for anti-NMDAR encephalitis, with older onset than expected. The onset of non-tumor-related AE occurred predominantly in the warm seasons, and AE with a more insidious onset was associated with delayed treatment initiation.

Anti-N-methyl-D-aspartate Receptor Encephalitis in People Living with HIV: Case Report and Literature Review.

With the increase in the number of cases of autoimmune encephalitis (AE), the cerebrospinal fluid (CSF) of people living with HIV (PLWH) showing abnormal behavior, cognitive impairment or abnormal movements should be actively screened for the antibody panel of AE. Early recognition and treatment can prevent severe seizures or coma and markedly improve the prognosis of patients. The first-line immunotherapy for AE includes intravenous methylprednisolone and immunoglobulin. However, whether long-time immunosuppressive maintenance therapy is needed is debated. For PLWH, immunosuppressive therapy and even steroids could be more challenging. Here, we review and summarize the clinical characteristics often reported cases and report one case from our center to improve the diagnosis and treatment of anti-N-methyl-D-aspartate receptor encephalitis in PLWH.

Seroprevalence of neuronal antibodies in diseases mimicking autoimmune encephalitis

Detection of neuronal antibodies for autoimmune encephalitis and paraneoplastic neurological syndromes relies on commercially available cell-based assays and lineblots. However, lineblots may reveal the presence of neuronal antibodies in patients with various non-autoimmune etiologies. Herein we describe patients with non-autoimmune etiologies (cohort B) and detectable neuronal antibodies and compare them to definite cases of autoimmune encephalitis (cohort A) for differences in clinical data. All patients positive for at least one neuronal antibody were retrospectively evaluated for autoimmune encephalitis and/or paraneoplastic neurological syndrome between 2016 and 2022. 39 cases in cohort B and 23 in cohort A were identified. In cohort B, most common diagnoses were neurodegenerative disorders in 9/39 (23.1%), brain tumors in 6/39 (15.4%) while most common detected antibodies were anti–titin (N10), anti-recoverin (N11), anti-Yo (N8) and all were detected in serum only. Differential aspects between cohort A and B were CSF pleocytosis (14/23 (60.8%) vs 11/35 (31.4%), p = 0.042, respectively), MRI features suggestive of encephalitis (6/23 (26.1%) vs 0 (0%), p = 0.002, respectively) and epilepsy restricted to temporal lobes (14/23 (60.9%) vs 2/30 (6.7%), p = 0.0003, respectively). A large proportion of lineblot results were non-specific when only serum was tested and were frequently found in non-autoimmune neurological conditions.

Nystagmus and Imbalance as the Presenting Symptoms of AntiGad Antibody Syndrome in A 67-Year-Old Female

Autoimmune encephalitis is a serious condition that causes brain inflammation, usually mediated by antibodies to various neuronal antigens [1]. One of the many antigens that may generate an immune response and cause this type of inflammation is the glutamic acid decarboxylase enzyme (GAD). AntiGAD (glutamic acid decarboxylase) antibodies are targeted against the GAD enzyme that converts glutamate to GABA, which is the nervous system’s primary inhibitory neurotransmitter [2]. With the body’s primary inhibitory neurotransmitter compromised, anti-GAD antibody syndrome is a rare type of autoimmune encephalitis that results in various symptoms related to prolonged excitation, such as seizures or nystagmus [3]. We present a rare case of autoimmune encephalitis caused by significantly elevated Anti-GAD antibody, with concomitant rheumatoid arthritis in the hands/wrists; symptoms of downbeat nystagmus, diplopia, headaches, and joint pain are improved with rituximab and IVIG infusion, following an unsuccessful treatment with oral prednisone.

Role of whole body MRI in paraneoplastic/autoimmune syndromes: An MRPET study to standardize protocols, pattern interpretation, and establish yield of MRI.

Imaging a case of autoimmune encephalitis (AIE) can be challenging as the underlying tumor may be occult. The aim of this retrospective case-based study is to evaluate role of whole-body MRI/Positron emission tomography (PET) in workup of AIE. Standardizing the whole-body MRI/PET protocol, Cross modality yield with serology and magnetic resonance/PET (MR/PET) and finally highlight the advantage of hybrid MR/PET. We present the retrospective review data from January 2016 to December 2019 referred for whole body MR/PET with suspected AIE/Paraneoplastic syndrome, per consensus criteria, treated at a single tertiary center. Analysis is done group wise based on referral being for oncological, immunological or neuropsychiatric condition. Detailed results with sensitivity and specificity are presented in tabular format with case-based review in our series for protocols and advantages of MR/PET. Among total of 600 MR/PET cases, 227 were suspected of AIE/paraneoplastic syndrome and were referred for whole body imaging. Distribution of Group 1 Known oncology group (n = 10), Group 2 Non oncological systemic illness group (n = 174) and group 3 the primary neuropsychiatric illness (n = 43) with Group 2 being largest. The gender distribution was similar and mean age was 42 years. Seronegative cases (n = 130) were greater than seropositive cases (n = 97). Seropositivity was in the following order Autoimmune > Paraneoplastic > Myositis panel. Whole body MRPET yielded occult malignancy in 9% and imaging abnormality in 88% of cases. Whole body MR/PET has an important role in workup of AIE. Selection of the appropriate protocol is important, especially when history and physical examination are nonspecific.

A case of autoimmune encephalitis in a patient with a solitary intracranial plasmacytoma.

A 65-year-old woman presented with fever and abnormal behavior. Magnetic resonance imaging showed swelling of the left medial temporal lobe and an intracranial extra-axial occipital tumor. While her neurological symptoms improved after the administration of corticosteroid therapy under the suspicion of autoimmune encephalitis, the occipital tumor unexpectedly shrank, and the diagnosis of a solitary plasmacytoma was confirmed by biopsy. Additional examinations revealed elevated anti-glutamate receptor antibodies in the cerebrospinal fluid. The patient was diagnosed with autoimmune encephalitis concurrent with an intracranial solitary plasmacytoma. Central nervous system involvement can be considered a neurological complication in patients with a solitary plasmacytoma.

A complex case of autoimmune encephalitis with renal twist - A case report

Autoimmune Encephalitis (AE) presents diagnostic challenges due to its diverse symptoms. We describe a case of a 32-year-old male with fever, seizures, and altered mental status, presented at Aga Khan hospital, Karachi, Pakistan. Unusual cerebrospinal fluid findings and autoimmune markers led to AE diagnosis. Autoimmune encephalitis’s intersection with lupus nephritis required a multidisciplinary approach, resulting in significant improvement. This case highlights the importance of clinical suspicion and antibody testing in AE diagnosis and offers insights into evolving autoimmune disease management.

The association between autoimmune encephalitis mediated by N-methyl-ᴅ-aspartate receptor autoantibodies and COVID-19: a systematic review.

Neurological complications related to coronavirus disease 2019 (COVID-19) infection have been increasingly reported. One of the most serious neurological complications is encephalitis, which could be due either to direct viral invasion or an immune-mediated inflammatory reaction. In this study, we conducted a systematic review of reported cases of autoimmune encephalitis mediated by N-methyl-ᴅ-aspartate receptor antibodies in conjunction with or after diagnosis of COVID-19 infection.

A complex case of young child with ADHD, developmental delay who developed seronegative autoimmune encephalitis exacerbated by stimulants

Autoimmune encephalitis (AE) is a group of disorders characterized by a wide clinical spectrum ranging from the typical limbic encephalitis to more complex neuropsychiatric symptoms including abnormal movements, psychosis, deficits in memory and cognition, dysautonomia, seizures, or coma. Psychiatric symptoms can occur early in the disease progress or manifest during its course. These symptoms are challenging and often slow down the diagnosis of AE. This is a crucial aspect considering that early diagnosis and management of AE are critical for a good outcome. However, there is a lack in studies outlining the exact symptomatology and specific appropriate care that would allow clinicians to achieve an early diagnosis and management. Additionally, AE in children mostly presents with neuropsychiatric symptoms and diagnosis is especially challenging in kids because of their limited capacity in describing their symptoms, the normal childhood behavioral changes and the possibility of a comorbid psychiatric diagnosis. We present a complex case of seronegative AE with comorbid ADHD (Attention Deficit Hyperactivity Disorder) and anxiety in a young six-year-old girl.

Autoimmune Encephalitis a Differential Diagnosis of Auditory Hallucination: A Case Report

Anti-N-Methyl-D-Aspartate Receptor (anti-NMDAR) has been the first specific-antibody type to be associated with Autoimmune Encephalitis [1]. Autoimmune encephalitis is associated with the neuropsychiatric symptoms including abrupt personality changes, cognitive decline, memory loss, perceptual disturbances among many others. Initial presentation might range from agitation, psychosis, and changes in speech, hallucinations, involuntary motor movements and autonomic dysfunction [2]. In general adult population are found to have higher association with paraneoplastic conditions and specific antibodies, but the pediatric age group do not show the strong association making the diagnosis a difficulty [3]. Also unlike adults association with cancer is also found to be less likely [4]. Due to these complications cases of autoimmune encephalitis are usually missed in pediatric population when focusing more on the psychiatric symptoms. Here we present a case of 14 year old boy who had a similar presentation.

Autoimmune anti-NMDA receptor encephalitis on the background of COVID-19: a clinical case

Background: During the new COVID-19 coronavirus infection pandemic, a growing incidence of autoimmune encephalitis cases has been observed. One of the primary problems related to patients with this highly lethal pathology is its timely early diagnostics and prescription of an optimal individual course of immunotherapy. In a debut of anti-NMDA receptor (inotropic glutamate receptor, selectively binding N-methyl D-aspartate) encephalitis, mental disorders are observed, prompting the initial admission of such patients to a psychiatric hospital. Then, the clinical picture of the disease is characterized by a significant polymorphism. In such cases, it is not always possible to suspect an autoimmune lesion of the nervous system. Clinical case description: In this article, we present a clinical case of a female patient with serologically confirmed autoimmune encephalitis against the background of the new coronavirus infection (U07.1 according to ICD-10). The disease onset involved psychiatric symptoms; the patient was transferred to the Department of neurology of the VGK BSMP No. 1 Municipal Clinical Hospital of Emergency Care No.1 from the municipal psychiatric hospital, when generalized cerebral symptoms appeared. According to the diagnostic criteria, mental disorders and generalized epileptic seizures are the most significant signs in the verification of autoimmune encephalitis. Autoimmune encephalitis was suspected based on the developed neurological symptoms and generalized epileptic seizures and confirmed by the detected anti-NMDA antibodies in the blood serum. The anti-NMDA antibody analysis in the blood and cerebrospinal fluid is the most informative way of autoimmune encephalitis diagnosis. Conclusion: Autoimmune encephalitis requires vigilance of physicians of all specialties who may encounter this disease. Timely diagnostic procedures and prescription of pathogenetically justified treatment are of importance.

MR Imaging Findings in a Large Population of Autoimmune Encephalitis.

Autoimmune encephalitis is a rare condition in which autoantibodies attack neuronal tissue, causing neuropsychiatric disturbances. This study sought to evaluate MR imaging findings associated with subtypes and categories of autoimmune encephalitis. Cases of autoimmune encephalitis with specific autoantibodies were identified from the medical record (2009-2019). Cases were excluded if no MR imaging of the brain was available, antibodies were associated with demyelinating disease, or >1 concurrent antibody was present. Demographics, CSF profile, antibody subtype and group (group 1 intracellular antigen or group 2 extracellular antigen), and MR imaging features at symptom onset were reviewed. Imaging and clinical features were compared across antibody groups using χ2 and Wilcoxon rank-sum tests. Eighty-five cases of autoimmune encephalitis constituting 16 distinct antibodies were reviewed. The most common antibodies were anti-N-methyl-D-aspartate (n = 41), anti-glutamic acid decarboxylase (n = 7), and anti-voltage-gated potassium channel (n = 6). Eighteen of 85 (21%) were group 1; and 67/85 (79%) were group 2. The median time between MR imaging and antibody diagnosis was 14 days (interquartile range, 4-26 days). MR imaging had normal findings in 33/85 (39%), and 20/33 (61%) patients with normal MRIs had anti-N-methyl-D-aspartate receptor antibodies. Signal abnormality was most common in the limbic system (28/85, 33%); 1/68 (1.5%) had susceptibility artifacts. Brainstem and cerebellar involvement were more common in group 1, while leptomeningeal enhancement was more common in group 2. Sixty-one percent of patients with autoimmune encephalitis had abnormal brain MR imaging findings at symptom onset, most commonly involving the limbic system. Susceptibility artifact is rare and makes autoimmune encephalitis less likely as a diagnosis. Brainstem and cerebellar involvement were more common in group 1, while leptomeningeal enhancement was more common in group 2.

Therapy response in seronegative versus seropositive autoimmune encephalitis.

Autoimmune encephalitis (AE) might be seropositive or seronegative, depending on whether antibodies targeting well-characterized neuronal antigens can be detected or not. Since data on treatment efficacy in seronegative cases, are scarce, the main rationale of this study was to evaluate immunotherapy response in seronegative AE in comparison to seropositive cases. An electronic database search retrospectively identified 150AE patients, treated in our tertiary care university hospital between 2010 and 2020 with an AE. Therapy response was measured using both general impression and the modified Rankin Scale (mRS). Seventy-four AE patients (49.3%) were seronegative and 76 (50.7%) seropositive. These cases were followed up for a mean of 15.3 (standard deviation, SD, 24.9) and 24.3 months (SD 28.1), respectively. Both groups were largely similar on the basis of numerous clinical and paraclinical findings including cerebrospinal fluid, electroencephalography, magnetic resonance imaging, and 18-F-fluor-desoxy-glucose-positron-emmission-tomography pathologies. The majority of patients (80.4%) received at least one immunotherapy, which were glucocorticoids in most cases (76.4%). Therapy response on general impression was high with 49 (92.5%) of treated seronegative, and 57 (86.4%) of treated seropositive AE cases showing improvement following immunotherapies and not significantly different between both groups. Notably, the proportion of patients with a favorable neurological deficit (mRS 0-2) was twice as high during long-term follow-up as compared to baseline in both groups. Since both, patients with seronegative and seropositive AE, substantially benefitted from immunotherapies, these should be considered in AE patients irrespective of their antibody results.

Diagnostic Relevance of the Medullary Vein Sign in Neurosarcoidosis (P9-5.003)

<h3>Objective:</h3> To evaluate the diagnostic potential of the medullary vein sign as an imaging marker in neurosarcoidosis. <h3>Background:</h3> Neurosarcoidosis is a rare manifestation of sarcoidosis that can be inferred through the clinical presentation, cerebral spinal fluid (CSF) analysis, and magnetic resonance imaging (MRI) scans. However, its accurate diagnosis remains a significant challenge due to the variability in its diagnostic criteria and the overlapping clinical and imaging features with other conditions. One under-researched finding in these patients is the engorgement of the medullary vein on susceptibility-weighted imaging (SWI), termed as the ‘medullary vein sign’; postulated to be a specific sign for neurosarcoidosis, its reliability has not yet been fully elucidated. <h3>Design/Methods:</h3> A single-center retrospective study was performed between March 31st, 2022, and August 1st, 2022. Two neuroradiologists independently examined MRI images using SWI/gradient echo sequences for medullary vein engorgement. A total of 32 patients were reviewed, and the diagnosis was based on imaging, biopsy, and CSF analysis. Finally, the sensitivity and specificity of the medullary vein sign were calculated. <h3>Results:</h3> Out of 32 patients, seven were diagnosed with definitive neurosarcoidosis; the remaining were classified as possible (n=16), probable (n=5), and other (n=4) causes of infectious meningoencephalitis, including two cases of autoimmune encephalitis. Among these, the medullary vein sign was detected in seven patients: five with confirmed, and two with possible neurosarcoidosis. Overall, the sensitivity was 71.4%, and the specificity was 92.3%. CSF was largely inconclusive, and MRI was not the major diagnostic factor in most cases. <h3>Conclusions:</h3> Our findings confirm the high specificity of the medullary vein sign for neurosarcoidosis and suggest that SWI is an effective tool for early detection, especially compared to conventional MRI and CSF analysis. Incorporating this in the current diagnostic criteria may result in timely intervention, and we encourage radiologists to look for this marker in patients with suspected neurosarcoidosis. <b>Disclosure:</b> Dr. Srivastava has nothing to disclose. Dr. Sharma has nothing to disclose. Dr. Joseph has nothing to disclose. Dr. Feizi has nothing to disclose. Dr. Sriwastava has nothing to disclose.

Characteristics and Treatment of anti-NMDAR Encephalitis in People Living with HIV: A Case Report and Literature Review (P5-5.005)

<h3>Objective:</h3> To describe the risk factors, symptoms, treatment, and outcomes of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis occurring in people living with HIV (PLWH). <h3>Background:</h3> Herpes simplex virus encephalitis is a known trigger of anti-NMDAR encephalitis. In recent years, multiple case reports also document anti-NMDAR encephalitis in PLWH, especially those who develop cerebrospinal fluid (CSF) escape, defined by an elevated CSF viral load in the setting of plasma viral suppression. Although the relationship between HIV and other viruses with anti-NMDAR encephalitis has not been fully elucidated, possible mechanisms include molecular mimicry or viral-induced release of NMDAR and other proteins as a result of neurotoxicity. HIV-induced functional dysregulation of CD4+ cell subtypes is another plausible contributor. <h3>Design/Methods:</h3> We conducted a literature search for published cases of autoimmune encephalitis in PLWH. We added an unpublished case from our center and described the clinical features of this unique cohort. <h3>Results:</h3> Eight published cases of anti-NMDAR encephalitis among PLWH were identified, as well as one unpublished case from our center. Common trends in these 9 cases include elevated CSF HIV viral load, T2 hyperintense lesions on MRI, and clinical improvement with immunomodulation. Our patient was a 51-year-old woman who presented off of antiretroviral therapy (recent CD4 range 199–252 cells/mm3) with status epilepticus and was found to have an elevated CSF HIV viral load and multiple non-enhancing T2-hyperintense lesions on brain MRI. Anti-NMDAR antibodies were positive in the serum and CSF. She did not respond to steroids or intravenous immunoglobulins, but began to improve after plasma exchange and was subsequently treated with rituximab. <h3>Conclusions:</h3> Anti-NMDAR encephalitis is an important, treatable consideration in PLWH who present with altered mental status or new seizures. Patients with an elevated CSF viral load may be at higher risk for this syndrome, and immunomodulation may be indicated even in patients who are immunosuppressed. <b>Disclosure:</b> Dr. White has nothing to disclose. Dr. Vila has nothing to disclose. The institution of Dr. Bissonnette has received research support from Michael J Fox Foundation. The institution of Dr. Bissonnette has received research support from Cogan Family Foundation. Dr. Martinez-Ramirez has nothing to disclose. Dr. Anand has nothing to disclose. Dr. Cervantes-Arslanian has nothing to disclose.