Cerebrospinal Fluid Findings in Patients With Autoimmune Encephalitis-A Systematic Analysis

Anti-NMDAR encephalitis for psychiatrists: the essentials

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis predominantly presents with psychiatric symptoms. Psychiatrists need to be alert to this diagnostic possibility, especially in female adolescents and young adults, as exemplified by the real (de-identified) case outlined below. Earlier diagnosis and immunotherapy improves long-term outcomes. Collaboration with neurology colleagues is essential for optimal care. 'Red flags' for autoimmune encephalitis and 'diagnostic clues' act as helpful aide memoires for this uncommon condition. The gold standard for testing is the detection of NMDAR antibodies in cerebrospinal fluid, but serum can be tested as a more accessible (but less reliable) preliminary step. The results of routine blood tests, magnetic resonance imaging of the head and electroencephalograms can be normal or show non-specific changes. Diagnostic criteria exist to define probable and definite cases. Immunotherapy for anti-NMDAR encephalitis is effective for many patients, but recovery is prolonged and relapses can occur.

Pathogenesis, diagnosis and treatment of paraneoplastic neurologic syndromes

Introduction: Paraneoplastic neurological syndromes (PNS) are a rare heterogeneous group of neurological diseases associated with tumors. These syndromes are the result of a cross-reactive immune response against antigens shared by the tumor and the nervous system. The discovery of an increasing number of autoantigens and the identification of tumoral factors leading to a substantial antitumoral immune response makes this topic highly innovative.Areas covered: This review covers the clinical, oncological, pathophysiological aspects of both immunological PNS groups. One is associated with autoantibodies against intracellular onconeural antibodies, which are highly specific for an underlying tumor, although the disease is mainly T-cell mediated. In contrast, PNS associated with pathogenic surface-binding/receptor autoantibodies, which are often responsive to immunosuppressive treatment, may manifest as paraneoplastic and non-paraneoplastic diseases. The most frequent tumors associated with PNS are (small cell) lung cancer, gynecological tumors, thymoma, lymphoma, and, in children, neuroblastoma. A special interest is given to PNS, induced by immune checkpoint-inhibitors (ICIs).Expert opinion: Research in PNS, including the group of ICI-induced PNS provide new insights in both the pathophysiology of PNS and tumor immune interactions and offers new treatment options for this group of severe neurological diseases.

CSF and Serum Biomarkers of Cerebral Damage in Autoimmune Epilepsy

Introduction: Our goal was to investigate whether biomarkers of cerebral damage are found in autoimmune-mediated epilepsy (AIE) and whether these can differentiate AIE from other seizure disorders.

Methods: We retrospectively searched our cerebrospinal fluid (CSF) database for patients with definite AIE, hippocampal sclerosis due to other causes (HS), genetic generalized epilepsy (GGE), and psychogenic, non-epileptic seizures (PNES). We measured serum and CSF tau, neurofilament 1 (NFL), glial fibrillary acid protein (GFAP), and ubiquitin-carboxy-terminal hydrolase L1 with a single-molecule array.

Results: We identified suitable samples from patients with AIE (n = 13) with different antibodies and compared them to HS (n = 13), GGE (n = 7), and PNES (n = 8). The NFL levels were significantly elevated in the serum (p = 0.0009) and CSF (p < 0.0019) of AIE patients. The AIE group was significantly older, while the disease duration was significantly shorter than in the control groups. NFL correlated significantly with age in all groups, and the NFL levels of AIE patients were hardly higher than those of healthy elderly people published elsewhere.

Conclusions: Our data indicate that the elevated NFL levels in AIE patients are most likely due to the higher age in this group and not due to the underlying inflammation. Unless larger prospective studies with intra-individual, longitudinal analyses and treatment responses would contradict our findings, NFL in serum might yet become a biomarker for disease activity and differential diagnosis.

Autoimmune Encephalitis in Late-Onset Seizures: When to Suspect and How to Treat

Objective: This study was conducted to elucidate prevalence, clinical features, outcomes, and best treatment in patients with late-onset seizures due to autoimmune encephalitis (AE). Methods: This is a single-institution prospective cohort study (2012-2019) conducted at the Epilepsy Center at the University of Greifswald, Germany. A total of 225 patients aged ≥50 years with epileptic seizures were enrolled and underwent an MRI/CT scan, profiling of neural antibodies (AB) in serum and cerebrospinal fluid (CSF), and neuropsychological testing. On the basis of their work-up, patients were categorized into the following three cohorts: definite, suspected, or no AE. Patients with definite and suspected AE were subsequently treated with immunosuppressive therapy (IT) and/or anti-seizure drug (ASD) therapy and were followed up (FU) regarding clinical and seizure outcome. Results: Of the 225 patients, 17 (8%) fulfilled the criteria for definite or suspected AE according to their AB profile and MRI results. Compared with patients with no evidence of AE, those with AE were younger (p = 0.028), had mesial temporal neuropsychological deficits (p = 0.001), frequently had an active or known malignancy (p = 0.006) and/or a pleocytosis (p = 0.0002), and/or had oligoclonal bands in CSF (p = 0.001). All patients with follow-up became seizure-free with at least one ASD. The Modified Rankin scale (mRS) at hospital admission was low for patients with AE (71% with mRS ≤2) and further decreased to 60% with mRS ≤2 at last FU. Significance: AE is an important etiology in late-onset seizures, and seizures may be the first symptom of AE. Outcome in non-paraneoplastic AE was favorable with ASD and IT. AB testing in CSF and sera, cerebral MRI, CSF analysis, and neuropsychological testing for mesial temporal deficits should be part of the diagnostic protocol for AE following late-onset seizures.

Seronegative limbic encephalitis manifesting as subacute amnestic syndrome: a case report and review of the literature

Background

Limbic encephalitis (LE), a variant of autoimmune encephalitis, is inflammation of the limbic system of the brain. The disorder presents with subacute impairment of short-term memory, psychiatric manifestations, confusion and seizures. “Seronegative LE” is a challenging diagnosis in the absence of well-characterized autoantibodies.

Case presentation

A 33-year-old Kuwaiti woman with no relevant past history presented with subacute progressive amnesia of 6-month duration. Magnetic resonance imaging (MRI) showed bilateral hyperintensity of the limbic structures. An extensive workup of the blood and cerebrospinal fluid (CSF) failed to identify paraneoplastic or autoimmune antibodies. The diagnosis of seronegative LE was made, and immunotherapy was initiated, with improvement in cognitive function.

Conclusion

Seronegative LE is a challenging diagnosis. Inability to detect autoantibodies, especially early in the disease course, should not rule out the diagnosis of autoimmune encephalitis. Early diagnosis and treatment with immunotherapy may prevent irreversible brain damage.

Longitudinal CSF Findings in Autoimmune Encephalitis-A Monocentric Cohort Study

Autoimmune encephalitis (AIE) poses a diagnostic challenge due to its heterogeneous clinical presentation, which overlaps with various neurological and psychiatric diseases. During the diagnostic work-up, cerebrospinal fluid (CSF) is routinely obtained, allowing for differential diagnostics as well as for the determination of antibody subclasses and specificities. In this monocentric cohort study, we describe initial and serial CSF findings of 33 patients diagnosed with antibody-associated AIE (LGI1 (n=8), NMDA (n=7), CASPR2 (n=3), IgLON5 (n=3), AMPAR (n=1), GAD65/67 (n=4), Yo (n=3), Ma-1/2 (n=2), CV2 (n=2)). Routine CSF parameters of 12.1% of AIE patients were in normal ranges, while 60.6% showed elevated protein levels and 45.4% had intrathecal oligoclonal bands (OCBs). Repeated CSF analyses showed a trend towards normalization of initial pathological CSF findings, while relapses were more likely to be associated with increased cell counts and total protein levels. OCB status conversion in anti-NMDARE patients coincided with clinical improvement. In summary, we show that in routine CSF analysis at diagnosis, a considerable number of patients with AIE did not exhibit alteration in the CSF and therefore, diagnosis may be delayed if antibody testing is not performed. Moreover, OCB status in anti-NMDAR AIE patients could represent a potential prognostic biomarker, however further studies are necessary to validate these exploratory findings.

Clinical Characteristics and Outcome of Neuronal Surface Antibody-Mediated Autoimmune Encephalitis Patients in a National Cohort

Background: In our previous single-center study of autoimmune encephalitis (AE) related autoantibody test results we found positivity in 60 patients out of 1,034 with suspected AE from 2012 through 2018 as part of a Hungarian nationwide program. In our current multicenter retrospective study, we analyzed the clinical characteristics and outcome of AE patients with positive neuronal cell surface autoantibody test results.

Methods: A standard online questionnaire was used to collect demographic and clinical characteristics, laboratory and imaging data, therapy and prognosis of 30 definitive AE patients in four major clinical centers of the region.

Results: In our study, 19 patients were positive for anti-NMDAR (63%), 6 patients (20%) for anti-LGI1, 3 patients for anti-GABABR (10%) and 3 patients for anti-Caspr2 (10%) autoantibodies. Most common prodromal symptoms were fever or flu-like symptoms (10/30, 33%). Main clinical features included psychiatric symptoms (83%), epileptic seizures (73%) and memory loss (50%). 19 patients (63%) presented with signs of central nervous system (CNS) inflammation, which occurred more frequently in elder individuals (p = 0.024), although no significant differences were observed in sex, tumor association, time to diagnosis, prognosis and immunotherapy compared to AE patients without CNS inflammatory markers. Anti-NMDAR encephalitis patients were in more severe condition at the disease onset (p = 0.028), although no significant correlation between mRS score, age, sex and immunotherapy was found. 27% of patients (n = 8) with associated tumors had worse outcome (p = 0.045) than patients without tumor. In most cases, immunotherapy led to clinical improvement of AE patients (80%) who achieved a good outcome (mRS ≤ 2; median follow-up 33 months).

Conclusion: Our study confirms previous publications describing characteristics of AE patients, however, differences were observed in anti-NMDAR encephalitis that showed no association with ovarian teratoma and occurred more frequently among young males. One-third of AE patients lacked signs of inflammation in both CSF and brain MRI, which emphasizes the importance of clinical symptoms and autoantibody testing in diagnostic workflow for early introduction of immunotherapy, which can lead to favorable outcome in AE patients.

Encephalopathy and encephalitis during acute SARS-CoV-2 infection. Spanish Society of Neurology's COVID-19 Registry

Objectives

Patients and methods

Results

Conclusions

Clinical Features, Treatment Strategies, and Outcomes in Hospitalized Children With Immune-Mediated Encephalopathies

BACKGROUND

Autoimmune encephalitis (AE) and acute disseminated encephalomyelitis (ADEM) are immune-mediated brain conditions that can cause substantial neurological sequalae. Data describing the clinical characteristics, treatments, and neurological outcomes for these conditions are needed.

METHODS

This is a single-center retrospective review of children diagnosed with AE or ADEM over a nine-year period with discharge outcomes measured by the Modified Rankin Score.

RESULTS

Seventy-five patients (23 with ADEM and 52 with AE) were identified. Patients with ADEM had a higher percentage of abnormal magnetic resonance imaging findings (100% vs 60.8%; P < 0.001) and a shorter time from symptom onset to diagnosis (6 vs 14 days; P = 0.024). Oligoclonal bands and serum and cerebrospinal fluid inflammatory indices were higher in patients with AE. Nearly all patients received corticosteroids followed by plasmapheresis or intravenous immunoglobulin, and treatment strategies did not differ significantly between groups. Second-line immune therapies were commonly used in patients with AE. Finally, patients with AE had trends toward longer hospital lengths of stay (21 vs 13 days) and a higher percentage of neurological disability at hospital discharge (59.6% vs 34.8%).

CONCLUSIONS

Although patients with ADEM and AE may have similar presenting symptoms, we found significant differences in the frequency of imaging findings, symptom duration, and laboratory and cerebrospinal fluid profiles, which can assist in distinguishing between the diagnoses. Patients in both groups were treated with a combination of immunomodulating therapies, and neurological disability was common at hospital discharge.

Encephalopathy and encephalitis during acute SARS-CoV-2 infection. Spanish Society of Neurology COVID-19 Registry

OBJECTIVES

Since the beginning of the COVID-19 pandemic, the Spanish Society of Neurology has run a registry of patients with neurological involvement for the purpose of informing clinical neurologists. Encephalopathy and encephalitis were among the most frequently reported complications. In this study, we analyse the characteristics of these complications.

PATIENTS AND METHODS

We conducted a retrospective, descriptive, observational, multicentre study of patients with symptoms compatible with encephalitis or encephalopathy, entered in the Spanish Society of Neurology's COVID-19 Registry from 17 March to 6 June 2020.

RESULTS

A total of 232 patients with neurological symptoms were registered, including 51 cases of encephalopathy or encephalitis (21.9%). None of these patients were healthcare professionals. The most frequent syndromes were mild or moderate confusion (33%) and severe encephalopathy or coma (9.8%). The mean time between onset of infection and onset of neurological symptoms was 8.02 days. Lumbar puncture was performed in 60.8% of patients, with positive PCR results for SARS-CoV-2 in only one case. Brain MRI studies were performed in 47% of patients, with alterations detected in 7.8% of these. EEG studies were performed in 41.3% of cases, detecting alterations in 61.9%.

CONCLUSIONS

Encephalopathy and encephalitis are among the complications most frequently reported in the registry. More than one-third of patients presented mild or moderate confusional syndrome. The mean time from onset of infection to onset of neurological symptoms was 8 days (up to 24hours earlier in women than in men). EEG was the most sensitive test in these patients, with very few cases presenting alterations in neuroimaging studies. All patients treated with boluses of corticosteroids or immunoglobulins progressed favourably.

Prognostic value of acute cerebrospinal fluid abnormalities in antibody-positive autoimmune encephalitis

OBJECTIVE

To examine the prognostic value of CSF abnormalities in seropositive autoimmune encephalitis (AE).

METHODS

We retrospectively studied 57 cases of seropositive AE. Primary outcomes were mortality and modified Rankin Scale, while secondary outcomes were first line treatment failure, ICU admission and relapse. Regression analysis was performed.

RESULTS

CSF white cell count (WCC) was higher in the NMDAR group, while elevated protein was more common amongst other subtypes. We found an association between WCC >5 cells/mm³ and treatment failure (OR 16.0, p = 0.006)), and between WCC >20 cells/mm³ and ICU admission (OR 19.3, p = 0.026).

CONCLUSIONS

Different subsets of AE have characteristic CSF abnormalities, which may aid recognition during early evaluation. CSF WCC had prognostic significance in our study.

Sleep Disturbances Associated with Neurological Autoimmunity

Associations between sleep disorders and neurological autoimmunity have been notably expanding recently. Potential immune-mediated etiopathogenesis has been proposed for various sleep disorders including narcolepsy, Kleine-Levin syndrome, and Morvan syndrome. Sleep manifestations are also common in various autoimmune neurological syndromes, but may be underestimated as overriding presenting (and potentially dangerous) neurological symptoms often require more urgent attention. Even so, sleep dysfunction has been described with various neural-specific antibody biomarkers, including IgLON5; leucine-rich, glioma-inactivated protein 1 (LGI1); contactin-associated protein 2 (CASPR2); N-methyl-D-aspartate (NMDA)-receptor; Ma2; dipeptidyl-peptidase-like protein-6 (DPPX); alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPA-R); anti-neuronal nuclear antibody type-1 (ANNA-1, i.e., Hu); anti-neuronal nuclear antibody type-2 (ANNA-2, i.e., Ri); gamma-aminobutyric acid (GABA)-B-receptor (GABA-B-R); metabotropic glutamate receptor 5 (mGluR5); and aquaporin-4 (AQP-4). Given potentially distinctive findings, it is possible that sleep testing could potentially provide objective biomarkers (polysomnography, quantitative muscle activity during REM sleep, cerebrospinal fluid hypocretin-1) to support an autoimmune diagnosis, monitor therapeutic response, or disease progression/relapse. However, more comprehensive characterization of sleep manifestations is needed to better understand the underlying sleep disruption with neurological autoimmunity.

Initial cerebrospinal fluid-restricted oligoclonal bands associate with anti-N-methyl-D-aspartate receptor encephalitis severity: a pilot study

Purpose

Intrathecal antibody production is thought to underly the pathogenesis and symptomatology of N-methyl-D-aspartate receptor encephalitis (NMDARE). In the present study, the clinical correlation of cerebrospinal fluid (CSF) restricted oligoclonal bands (OCBs), as a measure of intrathecal antibody synthesis, was examined in confirmed NMDARE cases.

Methods

The present study included patients with a confirmed diagnosis of NMDARE who underwent initial CSF evaluation and were followed up for a minimum of 12 months. Disease severity was assessed at baseline and 1, 3, 6, 9, and 12 months. Data regarding duration of hospitalization and intensive care unit (ICU) stay, the presence of uncontrolled seizures, and antiepileptic drug requirement were obtained for each patient.

Results

Among the 14 confirmed NMDARE patients, seven had CSF-OCBs. The presence of CSF-OCBs was associated with a more severe disease at baseline (p = 0.004), worse final outcome (p = 0.005), and longer hospitalization (median, 19 vs. 173 days; p < 0.001) and ICU stay (median, 0 vs. 29 days; p = 0.006). CSF-OCB positivity was closely associated with treatment refractoriness within 4 weeks (p = 0.029).

Conclusion

The presence of CSF-OCBs at the onset of disease in NMDARE patients was associated with initial treatment refractoriness and a more severe disease course leading to longer hospitalization, ICU admission, intractable seizures, and a poorer outcome. The results indicate that CSF-OCBs may be useful for prognostication. Furthermore, severe disease in NMDARE may be accompanied by oligoclonal expansion antibody-producing B cells.

Neuropsychiatric Disorders Due to Limbic Encephalitis: Immunologic Aspect

Limbic encephalitis (LE) is a rare cause of encephalitis presenting as an acute and subacute onset of neuropsychiatric manifestations, particularly with memory deficits and confusion as core features, along with seizure occurrence, movement disorders, or autonomic dysfunctions. LE is caused by neuronal antibodies targeting the cellular surface, synaptic, and intracellular antigens, which alter the synaptic transmission, especially in the limbic area. Immunologic mechanisms involve antibodies, complements, or T-cell-mediated immune responses in different degree according to different autoantibodies. Sensitive cerebrospinal fluid markers of LE are unavailable, and radiographic findings may not reveal a typical mesiotemporal involvement at neurologic presentations; therefore, a high clinical index of suspicions is pivotal, and a neuronal antibody testing is necessary to make early diagnosis. Some patients have concomitant tumors, causing paraneoplastic LE; therefore, tumor survey and treatment are required in addition to immunotherapy. In this study, a review on the molecular and immunologic aspects of LE was conducted to gain awareness of its peculiarity, which we found quite different from our knowledge on traditional psychiatric illness.

[Ictal electroencephalography (EEG) activity and cerebral blood flow dynamics as potential pathological indicators: a case of anti-leucine-rich glioma-inactivated 1 protein (LGI1) encephalitis]

A 29 year-old, right-handed woman was admitted to our hospital due to her headache with fever elevation lasting for two months followed by a prolonged loss of awareness with an involuntary movement in her left hand and mouth. This movement appeared very frequently, and the duration was very short, so called "faciobrachial dystonic seizures (FBDS)". Some of FBDS were followed by prolonged loss of awareness. Brain MRI fluid attenuated inversion recovery (FLAIR) image revealed high intensity lesion in the left mesial temporal lobe. Arterial spin labeling (ASL) image indicated hyper perfusion in this lesion and also the lateral temporal region. No ictal electroencephalography (EEG) change was observed before the onset of FBDS. FBDS was often followed by focal impaired awareness seizure (FIAS) in which ictal EEG showed rhythmic alpha activity arising from left mid-temporal region. This EEG seizure pattern was clearly visible in the time-frequency analysis. Given these clinical findings, along with an evidence of serum anti-leucine-rich glioma-inactivated 1 (LGI1) antibody positive, she was diagnosed with anti-LGI1 encephalitis. Immunotherapy (methylpredonisolone and intravenous immunoglobulin) with a multiple anti-epileptic drugs therapy (lacosamide, perampanel, and lamotrigine) was highly responsible to her symptoms. Although the high intensity lesion in FLAIR image still remained after the treatment, findings of ASL and EEG showed clear correlation to her cognitive function and seizures, respectively. Temporal change in ASL imaging suggested that the hyper perfusion in ASL during the acute stage could be provided by inflammation of the encephalitis its self and also the seizures activities (FBDS and FIAS). The pathophysiological indication of anti-LGI1 encephalitis was limited in terms of the therapeutic strategy, however, our findings collectively suggested that the combination analysis of EEG activity and cerebral blood flow dynamics (ASL) could be the potential candidate.

Search for Viral Infections in Cerebrospinal Fluid From Patients With Autoimmune Encephalitis

Background

It has been reported that virus-mediated brain tissue damage can lead to autoimmune encephalitis (AE) characterized by the presence of antibodies against neuronal surface antigens. In the study, we investigate the presence of viruses in cerebrospinal fluid (CSF) from patients with AE using reverse transcription polymerase chain reaction (RT-PCR)/PCR and shotgun metagenomics.

Methods

CSF samples collected from 200 patients with encephalitis were tested for the presence of antibodies against antiglutamate receptor (NMDAR), contactin-associated protein 2 (CASPR2), glutamate receptors (type AMPA1/2), leucine-rich glioma-inactivated protein 1 (LGI1), dipeptidyl aminopeptidase-like protein 6 (DPPX), and GABA B receptor, and those found positive were further analyzed with real-time RT-PCR/PCR for common viral neuroinfections and shotgun DNA- and RNA-based metagenomics.

Results

Autoantibodies against neuronal cells were detected in CSF from 8 individuals (4% of all encephalitis patients): 7 (3.5%) had anti-NMDAR and 1 (0.5%) had anti-GABA B. RT-PCR/PCR identified human herpes virus type 1 (HSV-1; 300 copies/mL) and the representative of Enterovirus genus (550 copies/mL) in 1 patient each. Torque teno virus (TTV) was found in another patient using metagenomic analysis, and its presence was confirmed by specific PCR.

Conclusions

We detected the presence of HSV, TTV, and Enterovirus genus in CSF samples from 3 out of 8 AE patients. These findings support the concept of viral involvement in the pathogenesis of this disease.

Anti-LGI1, anti-GABABR, and Anti-CASPR2 encephalitides in Asia: A systematic review

AIM

We aim to review the literature to collate and describe features of encephalitides arising from autoantibodies against leucine-rich glioma-inactivated 1 (LGI1), gamma aminobutyric acid receptor (GABABR), and contactin-associated protein-like 2 (CASPR2) in Asian populations and compare them with findings of Western studies.

METHODS

Peer-reviewed articles published till 24 May 2020 were searched, and original, full-text studies from Asia with serum/CSF antibody-based diagnosis and at least 2 patients were selected. Twenty-four studies with 263 patients (139 anti-LGI1, 114 anti-GAGABR, and 10 anti-CASPR2) were included. Data were pooled to produce descriptive information on demographics, clinical characteristics, diagnostics, treatments, and outcome.

RESULTS

The mean age was 54.2 (anti-LGI1), 55.2 (anti-GABABR), and 47.7 years (anti-CASPR2), with an overall male predominance of 62.0%. Commonest clinical features across all types were seizures (87.5%), memory deficits (80.7%), psychiatric disturbances (75.9%), and altered consciousness (52.9%). Four anti-LGI1, 40 anti-GABABR, and 1 anti-CASPR2 patients had tumors. CSF, MRI, and EEG were abnormal in 33.3%, 54.1%, and 75% patients in anti-LGI1; 60.0%, 49.6%, and 85.7% in anti-GABABR; and 50%, 44.4%, and 100% in anti-CASPR2 patients, respectively. 95.6% patients received first-line therapy alone (steroids/IVIG/Plasma therapy), and 4.4% received second-line therapy (rituximab/cyclophosphamide). 91.7%, 63.6%, and 70% of patients had favorable outcomes (modified Rankin Score 0-2) with mortality rates at 2.5%, 23.2%, and 0% in the three types, respectively.

CONCLUSION

Our findings suggest that these disorders present in Asian patients at a relatively young age often with features of seizures, memory deficits, and psychiatric disturbances and usually demonstrate a favorable clinical outcome.

Blood and cerebrospinal fluid immune cell profiles in patients with temporal lobe epilepsy of different etiologies

Inflammation plays a role in the pathogenesis of immune-mediated epilepsy, but also in epilepsy of other etiology such as hippocampal sclerosis. This study aimed to characterize immune cell signatures in the peripheral blood (PB) and cerebrospinal fluid (CSF) in temporal lobe epilepsy (TLE) of different etiologies. We retrospectively evaluated CSF routine parameters and immune cell profiles using flow cytometry in a cohort of 51 patients and 45 age-matched controls with functional disorders. Groups were comprised of patients with nonlesional TLE (n = 26), TLE due to hippocampal sclerosis (n = 14), or limbic encephalitis with antibodies against the 65-kDa isoform of glutamic acid decarboxylase (GAD65-LE; n = 11). TLE patients showed increased proportions of human leukocyte antigen-DR isotype (HLA-DR)-expressing CD4⁺ T lymphocytes in the CSF. Furthermore, they were characterized by a shift in monocyte subsets toward immature CD14^low CD16⁺ cells in the PB and blood/CSF-barrier dysfunction. Whereas TLE patients in general showed similar immune cell profiles, patients with GAD65-LE differed from other TLE patients by increased proportions of HLA-DR-expressing CD8⁺ T lymphocytes and type 2/3 oligoclonal bands. These findings point to a role of innate and adaptive immunity in TLE. CSF parameters may help to discriminate epilepsy patients from controls and different forms of TLE from each other.

Clinical characteristics of GAD 65-associated autoimmune encephalitis

OBJECTIVES

To examine the clinical characteristics of autoimmune encephalitis associated with the glutamate decarboxylase 65 (GAD 65) antibody.

MATERIALS AND METHODS

Medical records of all patients that diagnosed with GAD 65 antibody-associated encephalitis were retrospectively analyzed. Data regarding demographics and symptoms, neurological signs, laboratory and imaging results, treatment and prognosis were collected.

RESULTS

We collected a total of seven patients, mainly young or middle-aged women with a subacute or chronic course. The main clinical symptoms mainly included chronic epilepsy, cerebellar ataxia, stiff-person syndrome, and limbic encephalitis. Three of seven (43%) patients had high CSF (cerebrospinal fluid) protein levels. Oligoclonal IgG bands (including IgG 1) and 24 hours intrathecal synthesis of IgG were detected in CSF and serum in six patients, five patients (83%) reported increased distribution of oligoclonal IgG bands (including IgG 1) and 24 hours intrathecal synthesis of IgG in serum and CSF. And six of seven patients (86%) had abnormal thyroid function or were positive for thyroid antibodies. By electroencephalogram examination, sharp or slow waves in the temporal region were often observed for six of seven patients (86%). Abnormal imaging signals (six of seven patients, 86%) of the temporal lobe and hippocampus were detected by brain magnetic resonance imaging, and decreased metabolism of the temporal lobe was detected by positron emission tomography/computed tomography (six of six patients, 100%). These patients were mainly treated with corticosteroid and gamma globulin. The clinical symptoms of the patients were alleviated.

CONCLUSIONS

The course of GAD 65 antibody-associated encephalitis is longer than other autoimmune encephalitides. The clinical symptoms of GAD 65 autoimmune encephalitis mainly manifested as chronic epilepsy, cerebellar ataxia, stiff-person syndrome, and limbic encephalitis, and combined with or without thyroid autoimmune diseases, type 1 diabetes, and thymoma. A comprehensive understanding of the disease is a way to prevent misdiagnosis and delayed treatment.

Cerebrospinal fluid, antineuronal autoantibody, EEG, and MRI findings from 992 patients with schizophreniform and affective psychosis

The central role played by cerebrospinal-fluid (CSF) examinations including antineuronal autoantibody (Ab) testing is increasingly recognized in psychiatry. The rationale of this study was to present a multimodally investigated group of patients. In total, 992 patients were analyzed for CSF alterations: 456 patients with schizophreniform and 536 with affective syndromes. Ab measurement included testing for established antineuronal IgG-Abs against intracellular antigens in serum (Yo/Hu/Ri/cv2[CRMP5]/Ma1/Ma2/SOX1/TR[DNER]/Zic4/amphiphysin/GAD65) and for cell surface antigens in the CSF (NMDAR/AMPA-1/2-R/GABA-B-R/LGI1/CASPR2/DPPX). In 30 patients with "red flags" for autoimmune psychosis, "tissue tests" were performed. Additional diagnostics included MRI and EEG analyses. CSF white-blood-cell counts were increased in 4% and IgG indices in 2%; CSF-specific oligoclonal bands were detected in 4%; overall, 8% displayed signs of neuroinflammation. In addition, 18% revealed increased albumin quotients. Antineuronal Abs against intracellular antigens were detected in serum in 0.6%. Antineuronal Abs against established cell surface antigens were detected in serum of 1% and in the CSF of 0.3% (CSF samples were only questionably positive). Abnormal IgG binding in "tissue tests" was detected in serum of 23% and in CSF of 27%. In total, 92% of the Ab-positive patients demonstrated at least one sign of brain involvement in additional diagnostics using CSF, MRI, EEG, and FDG-PET. In summary, CSF basic analyses revealed signs of blood-brain-barrier dysfunction and neuroinflammation in relevant subgroups of patients. Established antineuronal IgG-Abs were rare in serum and even rarer in the CSF. "Tissue tests" revealed frequent occurrences of Ab-binding; therefore, novel antineuronal Abs could play a relevant role in psychiatry.

De novo nose-pinching stereotypy with somnolence: Clues to autoimmune encephalitis

Autoimmune encephalitis (AE) is being increasingly recognized as a cause of new-onset movement disorders. Movement disorders in AE are diverse and range from hyperkinetic conditions such as oromandibular dyskinesias, tremors and chorea to hypokinetic ones such as bradykinesia and parkinsonism. Stereotypies have been described in association with anti-NMDAR encephalitis. Similarly, sleep dysfunction is an underrecognized feature in many AE subtypes, prominently anti-IgLON5 although the correlation of phenotype of sleep dysfunction with a particular antibody subtype in AE is unclear. Despite the recognition of both these features as part of an overreaching spectrum in any patient with AE, seldom are they the sole presenting manifestations. Additionally, the challenge is further compounded in a patient who has seronegative AE since neither sleep disturbances nor stereotypies have been well characterized with this condition yet, and the diagnosis is conditional to exhausting a list of ancillary supportive features. In this brief communication, we describe the case of a young man who presented with hypersomnolence and an unusual focal nose-pinching stereotypy of subacute onset who lacked the presence of other typical clinical characteristics such as cognitive/memory impairment and seizures and had negative autoimmune antibodies but responded to immune therapy dramatically. We propose that the presence of de novo hypersomnolence and stereotypy should inform a potential diagnosis of AE.

Parkinsonian Syndrome with Frontal Lobe Involvement and Anti-Glycine Receptor Antibodies

Background: Atypical Parkinsonian syndromes with prominent frontal lobe involvement can occur in the 4R-taupathies progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). Secondary forms of movement disorders may occur in the context of autoimmune encephalitis with antineuronal antibodies, such as anti-glycine receptor (anti-GlyR) antibodies, which are typically associated with Stiff-Person spectrum syndrome, or progressive encephalomyelitis with rigidity and myoclonus. Overlaps between neurodegenerative and immunological mechanisms have been recently suggested in anti-IgLON5 disease. In this case study, the authors describe a patient with a Parkinsonian syndrome with frontal lobe involvement and anti-GlyR antibodies. Case presentation: The patient presented was a 63-year-old female. Her symptoms had begun with insomnia at the age of 60, after which, since the age of 61, increasing personality changes developed, leading to a diagnosis of depression with delusional symptoms. Severe cognitive deficits emerged, along with a left-side accentuated Parkinsonian syndrome with postural instability. The personality changes involved frontal systems. Magnetic resonance imaging (MRI) showed low-grade mesencephalon atrophy. [¹⁸F]fluorodeoxyglucose positron emission tomography (FDG PET) depicted a moderate hypometabolism bilateral frontal and of the midbrain, while [¹²³I]FPCIT single-photon emission computed tomography (SPECT) revealed severely reduced dopamine transporter availability in both striata, indicating pronounced nigrostriatal degeneration. In addition, anti-GlyR antibodies were repeatedly found in the serum of the patient (max. titer of 1:640, reference: <1:20). Therefore, an anti-inflammatory treatment with steroids and azathioprine was administered; this resulted in a decrease of antibody titers (to 1:80) but no detectable clinical improvement. The cerebrospinal fluid (CSF) and electroencephalography diagnostics showed inconspicuous findings, and negative CSF anti-GlyR antibody results. Conclusion: The patient presented here was suffering from a complex Parkinsonian syndrome with frontal lobe involvement. Because of the high anti-GlyR antibody titers, the presence of an autoimmune cause of the disorder was discussed. However, since no typical signs of autoimmune anti-GlyR antibody syndrome (e.g., hyperexcitability, anti-GlyR antibodies in CSF, or other inflammatory CSF changes) were detected, the possibility that the anti-GlyR antibodies might have been an unrelated bystander should be considered. Alternatively, the anti-GlyR antibodies might have developed secondarily to neurodegeneration (most likely a 4-repeat tauopathy, PSP or CBD) without exerting overt clinical effects, as in cases of anti-IgLON5 encephalopathy. In this case, such antibodies might also potentially modify the clinical course of classical movement disorders. Further research on the role of antineuronal antibodies in Parkinsonian syndromes is needed.

Psychiatric Manifestation of Anti-LGI1 Encephalitis

Background: Anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis is typically characterized by limbic encephalitis, faciobrachial dystonic seizures and hyponatremia. The frequency with which milder forms of anti-LGI1 encephalitis mimic isolated psychiatric syndromes, such as psychoses, or may lead to dementia if untreated, is largely unknown. Case presentation: Here, the authors present a 50-year-old patient who had suffered from neurocognitive deficits and predominant delusions for over one and a half years. He reported a pronounced feeling of thirst, although he was drinking 10–20 liters of water each day, and he was absolutely convinced that he would die of thirst. Due to insomnia in the last five years, the patient took Z-drugs; later, he also abused alcohol. Two years prior to admission, he developed a status epilepticus which had been interpreted as a withdrawal seizure. In his serum, anti-LGI1 antibodies were repeatedly detected by different independent laboratories. Cerebrospinal fluid analyses revealed slightly increased white blood cell counts and evidence for blood–brain-barrier dysfunction. Magnetic resonance imaging showed hyperintensities mesio-temporally and in the right amygdala. In addition, there was a slight grey–white matter blurring. A cerebral [¹⁸F] fluorodeoxyglucose positron emission tomography (FDG-PET) examination of his brain showed moderate hypometabolism of the bilateral rostral mesial to medial frontal cortices. Treatment attempts with various psychotropic drugs remained unsuccessful in terms of symptom relief. After the diagnosis of probable chronified anti-LGI1 encephalitis was made, two glucocorticoid pulse treatments were performed, which led to a slight improvement of mood and neurocognitive deficits. Further therapy was not desired by the patient and his legally authorized parents. Conclusion: This case study describes a patient with anti-LGI1 encephalitis in the chronified stage and a predominant long-lasting psychiatric course with atypical symptoms of psychosis and typical neurocognitive deficits. The patient’s poor response to anti-inflammatory drugs was probably due to the delayed start of treatment. This delay in diagnosis and treatment may also have led to the FDG-PET findings, which were compatible with frontotemporal dementia (“state of damage”). In similar future cases, newly occurring epileptic seizures associated with psychiatric symptoms should trigger investigations for possible autoimmune encephalitis, even in patients with addiction or other pre-existing psychiatric conditions. This should in turn result in rapid organic clarification and—in positive cases—to anti-inflammatory treatment. Early treatment of anti-LGI1 encephalitis during the “inflammatory activity state” is crucial for overall prognosis and may avoid the development of dementia in some cases. Based on this case, the authors advocate the concept—long established in many chronic inflammatory diseases in rheumatology—of distinguishing between an “acute inflammatory state” and a “state of organ damage” in autoimmune psychosis resembling neurodegenerative mechanisms.

Sleep Disturbances in Patients with Autoimmune Encephalitis

PURPOSE OF REVIEW

To review sleep complaints reported in patients with autoimmune encephalitis, explore the relationship between sleep disturbances and subtypes of autoimmune encephalitis, and leverage knowledge concerning antibody-antigen specificity to inform the receptors, structures, and disseminated neural networks that contribute to sleep function in health and disease.

RECENT FINDINGS

Autoimmune encephalitis is an inflammatory brain disorder characterized by the subacute onset of psychiatric symptoms, cognitive impairment, and focal neurologic deficits or seizures. Sleep disturbances are detected in a majority of patients systematically screened for sleep complaints, may be the presenting symptom in patients with autoimmune encephalitis, and may compromise recovery in patients with autoimmune encephalitis. Early recognition of specific sleep disturbances in patients with subacute changes in behavior or cognition may support the diagnosis of autoimmune encephalitis. Similarly, recognition and treatment of sleep dysfunction in patients with known autoimmune encephalitis may speed recovery and improve long-term outcomes.

Searching for autoimmune encephalitis: Beware of normal CSF

OBJECTIVE

To determine the prevalence of cerebrospinal fluid (CSF) markers associated with inflammation (i.e., elevated white blood cell count, protein concentration, and CSF-specific oligoclonal bands) in patients with early active autoimmune encephalitis (AE).

METHODS

CSF characteristics, including WBC count, protein concentration, and oligoclonal banding, were analyzed in patients diagnosed with AE at two tertiary care centers.

RESULTS

Ninety-five patients were included in the study. CSF white blood cell counts and protein levels were within normal limits for 27% (CI_95%: 19-37) of patients with AE. When results of oligoclonal banding were added, 14% (CI_95%: 6-16) of patients with AE had "normal" CSF. The median CSF white blood cell count was 8 cells/mm³ (range: 0-544) and the median CSF protein concentration was 0.42 g/L (range: 0.15-3.92).

CONCLUSIONS

White blood cell counts and protein levels were within normal limits in the CSF of a substantial proportion of patients with early active AE. Inclusion of CSF oligoclonal banding identified a higher proportion of patients with an inflammatory CSF profile, especially when CSF was sampled early in the disease process.

Clinical Characteristics of Anti-GABA-B Receptor Encephalitis

Objective: Anti-GABA-B (gamma aminobutyric acid-B) receptor encephalitis is an autoimmune disease mediated by GABA-B-related antibodies. To fully understand the disease, we collected clinical data from patients with GABA-B receptor encephalitis and conducted an analysis to draw conclusions. Methods: All patients with GABA-B receptor encephalitis from the Neurology Department of Beijing Tiantan Hospital, affiliated with Capital Medical University, from August 2015 to September 2019 were accepted as study subjects. The clinical data of the patients were analyzed retrospectively and included the general demographic characteristics, clinical manifestations, and auxiliary examinations, including laboratory results, electroencephalograms (EEGs), brain magnetic resonance imaging (MRI), and positron emission tomography (PET-CT) results, as well as treatments. Results: From August 2015 to September 2019, 14 cases of anti-GABA-B receptor encephalitis were diagnosed. Among these patients, middle-aged and elderly men were the main demographic, with an average age of 52 years; moreover, the onset of the disease was relatively sudden, and the time from onset to diagnosis was ~1 month. The main clinical symptoms were frequent epileptic seizures, cognitive dysfunction, and mental behavioral disorders. In seven (50%) patients, the leukocyte in cerebrospinal fluid (CSF) were increased. Five (36%) patients had elevated cerebrospinal fluid protein. In most patients, the oligoclonal bands (83%) of CSF were positive, and 24 h IgG levels (92%) were increased. Anti-Hu or anti-Yo antibodies were positive in two (14%) patients. Tumor markers in 10 (71%) patients indicated that neuron-specific enolase, gastrin-releasing precursor, non-small cell lung cancer-related antigen, or carcinoembryonic antigen levels were increased. EEG results often indicated slow waves, sharp waves, or spike waves in temporal areas. Brain MRI always showed high T2 signals in the medial temporal lobe, hippocampus, and amygdala and swelling in the medial temporal lobe and hippocampus. PET-CT scans almost showed abnormal metabolism in the hippocampus and temporal lobe. Three (21%) patients who underwent systemic PET-CT showed hypermetabolism in pulmonary parenchymal nodules and enlargement of mediastinal lymph nodes. All patients underwent high-dose hormone therapy or immunoglobulin immunotherapy. After treatment, the symptoms of epilepsy, cognitive disorders, and mental behavioral disorders improved to varying degrees. However, one patient died of lung cancer. Conclusion: Anti-GABA-B receptor encephalitis mainly occurred in middle-aged and elderly men, and the disease onset was relatively sudden. Before disease onset, some patients experienced fever and non-specific respiratory symptoms, which mainly manifested as frequent epileptic seizures, cognitive dysfunction, and abnormal mental behavior. MRI and PET-CT revealed abnormal signals and local metabolism, respectively, in the temporal lobe. Moreover, the disease has a close relationship with lung cancer, which requires long-term follow-up observation.

SOP: antibody-associated autoimmune encephalitis

Background

Antibody-mediated and paraneoplastic autoimmune encephalitides (AE) present with a broad spectrum of clinical symptoms. They often lead to progressing inflammatory changes of the central nervous system with subacute onset and can cause persistent brain damage. Thus, to promptly start the appropriate and AE-specific therapy, recognition of symptoms, initiation of relevant antibody diagnostics and confirmation of the clinical diagnosis are crucial, in particular as the diseases are relatively rare.

Aim

This standard operating procedure (SOP) should draw attention to the clinical presentation of AE, support the diagnostic approach to patients with suspected AE and guide through the necessary steps including therapeutic decisions, tumour screening and exclusion of differential diagnoses.

Method

Based on existing diagnostic algorithms, treatment recommendations and personal experiences, this SOP gives an overview of clinical presentation, diagnostic procedures and therapy in AE. Additional information is provided within an accompanying text and a table describing the most important autoantibodies and their characteristics.

Results

The initial steps of the AE flow chart are based on clinical symptoms and the patient’s history. Assignment to paraneoplastic or antibody-mediated AE is sometimes clinically possible. Diagnostics should include MRI, EEG and CSF analysis with antibody panel diagnostic. Definite AE can be diagnosed if the underlying antibody is compatible with the clinical presentation. Classification of probable AE may be possible even with negative anti-neuronal autoantibodies if the clinical presentation and laboratory abnormalities are highly suggestive of AE. The confirmed AE diagnosis requires immediate initiation of immunotherapy.

Conclusion

The SOP facilitates the recognition of patients with AE and presents the necessary diagnostic and therapeutic steps.

Clinical Classifications of Children With Psychogenic Non-epileptic Seizure

Objective: To analyze the clinical features of children with psychogenic non-epileptic seizures in one tertiary center in China. Methods: Clinical data including medical records and video- electroencephalograph (video-EEG) monitoring records of 88 pediatric PNES patients hospitalized in the pediatric department of Xuanwu Hospital, Beijing, China from April, 2012 to April, 2018 were collected in this study. Demographic information of patients, semiological classification, duration, and frequency of symptoms, risk factors as well as comorbidity were summarized and analyzed. Results: For semiological classification, all PNES related symptoms were divided into different categories: motor symptoms, unresponsiveness, sensory symptoms, visceral symptoms, and abnormal behaviors, among which motor symptoms were the most prevalent form. Risk factors were reviewed and categorized into two groups: persistent factors and predisposing factors, and patients were most frequently affected by the influences of families. The duration and frequency of symptoms varied substantially within PNES patients while the average time of duration was relatively longer than epilepsy as reported previously. Epilepsy was considered as the most frequent comorbidity of PNES and PNES patients misdiagnosed as epilepsy often mistreated with antiseizure medication. Significance: Our study showed that motor PNES are the most frequent seizure type. Family issues were a risk factor for PNES. Epilepsy was the most frequent co-existing neurological comorbidity.

Autoimmune encephalitis as a differential diagnosis of schizophreniform psychosis: clinical symptomatology, pathophysiology, diagnostic approach, and therapeutic considerations

Primary schizophreniform psychoses are thought to be caused by complex gene-environment interactions. Secondary forms are based on a clearly identifiable organic cause, in terms of either an etiological or a relevant pathogenetic factor. The secondary or "symptomatic" forms of psychosis have reentered the focus stimulated by the discovery of autoantibody (Ab)-associated autoimmune encephalitides (AEs), such as anti-NMDA-R encephalitis, which can at least initially mimic variants of primary psychosis. These newly described secondary, immune-mediated schizophreniform psychoses typically present with the acute onset of polymorphic psychotic symptoms. Over the course of the disease, other neurological phenomena, such as epileptic seizures, movement disorders, or reduced levels of consciousness, usually arise. Typical clinical signs for AEs are the acute onset of paranoid hallucinatory symptoms, atypical polymorphic presentation, psychotic episodes in the context of previous AE, and additional neurological and medical symptoms such as catatonia, seizure, dyskinesia, and autonomic instability. Predominant psychotic courses of AEs have also been described casuistically. The term autoimmune psychosis (AP) was recently suggested for these patients. Paraclinical alterations that can be observed in patients with AE/AP are inflammatory cerebrospinal fluid (CSF) pathologies, focal or generalized electroencephalographic slowing or epileptic activity, and/or suspicious "encephalitic" imaging findings. The antibody analyses in these patients include the testing of the most frequently found Abs against cell surface antigens (NMDA-R, CASPR2, LGI1, AMPA-R, GABA_B-R), intracellular antigens (Hu, Ri, Yo, CV2/CRMP5, Ma2 [Ta], amphiphysin, GAD65), thyroid antigens (TG, TPO), and antinuclear Abs (ANA). Less frequent antineuronal Abs (e.g., against DPPX, GABA_A-R, glycine-R, IgLON5) can be investigated in the second step when first step screening is negative and/or some specific clinical factors prevail. Beyond, tissue-based assays on brain slices of rodents may detect previously unknown antineuronal Abs in some cases. The detection of clinical and/or paraclinical pathologies (e.g., pleocytosis in CSF) in combination with antineuronal Abs and the exclusion of alternative causes may lead to the diagnosis of AE/AP and enable more causal therapeutic immunomodulatory opportunities.

Clinical Approach to Autoimmune Epilepsy

Autoimmune epilepsy is a newly emerging area of epilepsy. The concept of “autoimmune” as an etiology has recently been revisited thanks to advances in autoimmune encephalitis and precision medicine with immunotherapies. Autoimmune epilepsy presents with specific clinical manifestations, and various diagnostic approaches including cerebrospinal fluid analysis, neuroimaging, and autoantibody tests are essential for its differential diagnosis. The diagnosis is often indeterminate despite performing a thorough evaluation, and therefore empirical immunotherapy may be applied according to the judgment of the clinician. Autoimmune epilepsy often manifests as new-onset refractory status epilepticus (NORSE). A patient classified as NORSE should receive empirical immunotherapy as soon as possible. On the other hand, a morecautious, stepwise approach is recommended for autoimmune epilepsy that presents with episodic events. The type of autoimmune epilepsy is also an important factor to consider when choosing from among various immunotherapy options. Clinicians should additionally take the characteristics of antiepileptic drugs into account when using them as an adjuvant therapy. This expert opinion discusses the diagnostic and treatment approaches for autoimmune epilepsy from a practical point of view.