Seasonal variation in autoimmune encephalitis: A multi-center retrospective study

NORSE seasonality may vary geographically in adults

The mechanisms causing new onset refractory status epilepticus (NORSE) are often unknown. Recently, a seasonal variation with NORSE peaking during the summer was described in a mixed cohort of adults and children why we here studied the seasonal variation in a Danish status epilepticus (SE) cohort. This retrospective cohort study comprised SE patients aged ≥18 diagnosed and treated 2008-2017 at the Odense University Hospital. Clinical characteristics and seasonality of patients fulfilling the diagnostic criteria for NORSE were compared with patients with refractory SE (RSE) due to other reasons and with the seasonal variation of autoantibodies associated with autoimmune encephalitis in the Danish autoimmune encephalitis register. In this cohort, 26 patients met NORSE criteria. As compared to RSE patients not fulfilling NORSE criteria (n = 152), NORSE patients were more likely to have symptoms of systemic inflammation (C-reactive protein concentrations ≥10 mg/L or fever ≥38°C) at admission; nine fulfilled the criteria for febrile infection related epilepsy syndrome (FIRES). In contrast to the even seasonal distribution of patients with RSE not fulfilling the NORSE criteria, admissions due to NORSE peaked during the winter (46.1%, p = 0.04 as compared to non-NORSE RSE); six out of nine FIRES episodes occurred in the winter season. The seasonal variation was not explained by a seasonal variation of the detection rates of autoantibodies associated with autoimmune encephalitis (incl. NMDAR, LGI1, CASPR2, GABAR, GFAP) in a Danish nationwide register (n = 259). In conclusion, we confirm the seasonality of NORSE in a Danish cohort, however, with a peak during winter suggesting a geographical variation not solely explained by autoimmune encephalitis associated with known autoantibodies. PLAIN LANGUAGE SUMMARY: The study investigated the seasonal patterns of new-onset refractory status epilepticus (NORSE), i.e. severe seizures that occur without an obvious cause and require very intensive treatment. In contrast to the previously observed peak frequency in summer, this Danish study found that NORSE cases peak in winter. Furthermore, the seasonal variation in NORSE cases was not found to be associated with autoimmune encephalitis caused by known autoantibodies. Together with the high rate of patients showing symptoms of systemic inflammation compared to other status epilepticus patients, the data suggest a link between misdirected immune system responses and NORSE. The study can therefore help in the further search for the currently unknown causes of NORSE.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Immune pathogenesis of idiopathic granulomatous mastitis: from etiology toward therapeutic approaches

Idiopathic granulomatous mastitis (IGM) is a noncancerous, chronic inflammatory disorder of breast with unknown causes, posing significant challenges to the quality of life due to its high refractoriness and local aggressiveness. The typical symptoms of this disease involve skin redness, a firm and tender breast mass and mastalgia; others may include swelling, fistula, abscess (often without fever), nipple retraction, and peau d'orange appearance. IGM often mimics breast abscesses or malignancies, particularly inflammatory breast cancer, and is characterized by absent standardized treatment options, inconsistent patient response and unknown mechanism. Definite diagnosis of this disease relies on core needle biopsy and histopathological examination. The prevailing etiological theory suggests that IGM is an autoimmune disease, as some patients respond well to steroid treatment. Additionally, the presence of concurrent erythema nodosum or other autoimmune conditions supports the autoimmune nature of the disease. Based on current knowledge, this review aims to elucidate the autoimmune-favored features of IGM and explore its potential etiologies. Furthermore, we discuss the immune-mediated pathogenesis of IGM using existing research and propose immunotherapeutic strategies for managing this condition.

Seasonality of presentation and birth in catatonia

BACKGROUND

Catatonia is a neuropsychiatric syndrome associated with both psychiatric disorders and medical conditions. Understanding of the pathophysiology of catatonia remains limited, and the role of the environment is unclear. Although seasonal variations have been shown for many of the disorders underlying catatonia, the seasonality of this syndrome has not yet been adequately explored.

METHODS

Clinical records were screened to identify a cohort of patients suffering from catatonia and a control group of psychiatric inpatients, from 2007 to 2016 in South London. In a cohort study, the seasonality of presentation was explored fitting regression models with harmonic terms, while the effect of season of birth on subsequent development of catatonia was analyzed using regression models for count data. In a case-control study, the association between month of birth and catatonia was studied fitting logistic regression models.

RESULTS

In total, 955 patients suffering from catatonia and 23,409 controls were included. The number of catatonic episodes increased during winter, with a peak in February. Similarly, an increasing number of cases was observed during summer, with a second peak in August. However, no evidence for an association between month of birth and catatonia was found.

CONCLUSIONS

The presentation of catatonia showed seasonal variation in accordance with patterns described for many of the disorders underlying catatonia, such as mood disorders and infections. We found no evidence for an association between season of birth and risk of developing catatonia. This may imply that recent triggers may underpin catatonia, rather than distal events.

Neurological syndromes and potential triggers associated with antibodies to neuronal surface antigens

BACKGROUND

Autoantibodies against surface neuronal antigens have been associated with specific neurological presentations including autoimmune encephalitis (AE), with variable association with neoplasia and infections.

METHODS

We described the phenotype and environmental associations of patients with neurological syndromes associated with antibodies against neuronal surface antigens who were referred to a tertiary center in the South of Brazil. All patients were tested for neuronal autoantibodies using cell-based assays. Clinical, radiological, and laboratory findings were retrospectively reviewed.

RESULTS

We identified 16 patients, 15 had subacute, and one had a progressive disease course. Among patients with subacute onset, 11 (73 %) were N-Methyl-d-Aspartate receptor (NMDAr-IgG)+, 3 (20 %) were Leucine-rich Glioma-Inactivated-1 (LGI1-IgG)+, and 1 (6 %) was positive for Glycine receptor-IgG. The patient with a progressive disease course had antibodies against IgLON5. Most patients had disease onset in spring and summer suggesting environmental factors for the development of AE. Also, we observed a different pattern of brain lesions when NMDAr-IgG encephalitis followed herpes encephalitis and a previously unreported association with Rosai-Dorfman-Destombe disease. All patients with encephalopathy met criteria for possible AE and all proven NMDAr-IgG+ met criteria for NMDAr-IgG encephalitis. However, only one LGI1-IgG+ patient fulfilled clinical criteria for limbic encephalitis. All but one received high-dose intravenous methylprednisolone, 11 also had intravenous human immunoglobulin, and 4 plasma exchange. Furthermore, all patients received second-line immunotherapy. Importantly, most patients improved with immunotherapy, even when initiated later in the disease course.

CONCLUSION

We identified seasonal variability associated with neuronal surface antibodies suggesting environmental triggers. Also, we described the coexistence of NMDAr-IgG encephalitis with histiocytosis. In our series, most patients received second-line immunotherapy. We observed neurologic improvement after treatment even in cases of delayed diagnosis. Increasing the recognition and availability of tests and treatments for these conditions is of paramount importance in low- and middle-income countries.

Brazilian autoimmune encephalitis network (BrAIN): antibody profile and clinical characteristics from a multicenter study

Background

The frequency of antibodies in autoimmune encephalitis (AIE) may vary in different populations, however, data from developing countries are lacking. To describe the clinical profile of AIE in Brazil, and to evaluate seasonality and predictors of AIE in adult and pediatric patients.

Methods

We evaluated patients with possible AIE from 17 centers of the Brazilian Autoimmune Encephalitis Network (BrAIN) between 2018 and 2022. CSF and serum were tested with TBAs and CBAs. Data on clinical presentation, complementary investigation, and treatment were compiled. Seasonality and predictors of AIE in adult and pediatric populations were analyzed.

Results

Of the 564 patients, 145 (25.7%) were confirmed as seropositive, 69 (12.23%) were seronegative according to Graus, and 58% received immunotherapy. The median delay to diagnosis confirmation was 5.97 ± 10.3 months. No seasonality variation was observed after 55 months of enrolment. The following antibodies were found: anti-NMDAR (n=79, 54%), anti-MOG (n=14, 9%), anti-LGI1(n=12, 8%), anti-GAD (n=11, 7%), anti-GlyR (n=7, 4%), anti-Caspr2 (n=6, 4%), anti-AMPAR (n=4, 2%), anti-GABA-BR (n=4, 2%), anti-GABA-AR (n=2, 1%), anti-IgLON5 (n=1, 1%), and others (n=5, 3%). Predictors of seropositive AIE in the pediatric population (n=42) were decreased level of consciousness (p=0.04), and chorea (p=0.002). Among adults (n=103), predictors of seropositive AIE were movement disorders (p=0.0001), seizures (p=0.0001), autonomic instability (p=0.026), and memory impairment (p=0.001).

Conclusion

Most common antibodies in Brazilian patients are anti-NMDAR, followed by anti-MOG and anti-LGI1. Only 26% of the possible AIE patients harbor antibodies, and 12% were seronegative AIE. Patients had a 6-month delay in diagnosis and no seasonality was found. Findings highlight the barriers to treating AIE in developing countries and indicate an opportunity for cost-effect analysis. In this scenario, some clinical manifestations help predict seropositive AIE such as decreased level of consciousness, chorea, and dystonia among children, and movement disorders and memory impairment among adults.

Seasonal Variation in Neurologic Hospitalizations in the United States

OBJECTIVE

Certain neurologic diseases have been noted to vary by season, and this is important for understanding disease mechanisms and risk factors, but seasonality has not been systematically examined across the spectrum of neurologic disease, and methodologic guidance is also lacking.

METHODS

Using nationally representative data from the National Inpatient Sample, a stratified 20% sample of all non-federal acute care hospitalizations in the United States, we calculated the monthly rate of hospitalization for 14 neurologic diseases from 2016 to 2018. For each disease, we assessed seasonality of hospitalization using chi-squared, Edward, and Walter-Elwood tests and seasonal time series regression models. Statistical tests were adjusted for multiple hypothesis testing using Bonferroni correction.

RESULTS

Meningitis, encephalitis, ischemic stroke, intracerebral hemorrhage, Guillain-Barre syndrome, and multiple sclerosis had statistically significant seasonality according to multiple methods of testing. Subarachnoid hemorrhage, status epilepticus, myasthenia gravis, and epilepsy had significant seasonality according to Edwards and Walter-Elwood tests but not chi-square tests. Seasonal time series regression illustrated seasonal variation in all 14 diseases of interest, but statistical testing for seasonality within these models using the Kruskal-Wallis test only achieved statistical significance for meningitis.

INTERPRETATION

Seasonal variation is present across the spectrum of acute neurologic disease, including some conditions for which seasonality has not previously been described, and can be examined using multiple different methods. ANN NEUROL 2023;93:743-751.

Changes in the Rate of Leucine-Rich Glioma-Inactivated 1 Seropositivity During the COVID-19 Lockdown

This case-control study investigates the positivity rates of the most prevalent neuroglial surface antibodies during the COVID-19 pandemic.

Evaluation of CSF albumin quotient in neuronal surface antibody-associated autoimmune encephalitis

Background and Objectives

Disruption of brain barriers is considered to be involved in the pathogenesis of neuronal surface antibody-associated autoimmune encephalitis (NSAE), but few studies have focused on their relationship. We aimed to explore the association between the integrity of brain barriers and clinical and paraclinical characteristics in patients with NSAE.

Methods

This retrospective study consecutively recruited patients with NSAE. The cerebrospinal fluid (CSF) / serum albumin quotient (Qalb) was used to evaluate the function of brain barriers. The data on demographic information, clinical manifestations, magnetic resonance imaging (MRI), CSF findings and prognosis were collected and analyzed.

Results

Of the 93 patients included, 33 (35.5%) patients were assigned to the elevated Qalb group and 60 (64.5%) patients to the normal Qalb group. Males and prodromal symptoms were more common in elevated Qalb group (both P < 0.05). The CSF white blood cell, protein, immunoglobulin G and albumin were significantly higher in elevated Qalb group (all P < 0.05). Patients with elevated Qalb were more likely to have brain lesions on MRI (60.6% versus 33.3%, P = 0.011). The modified Rankin Scale (mRS) scores at discharge and at last follow-up were significantly higher in patients with elevated Qalb than those with normal Qalb (both P < 0.05). After univariate and multivariate analyses, Qalb elevation (adjusted odds ratio = 3.96, 95% confidence interval = 1.15–13.59, P = 0.029) was demonstrated as the only independent risk factor for a poor prognosis.

Discussion

Males, prodromal symptoms, brain lesions on MRI, CSF pleocytosis, and elevated CSF protein were more common in NSAE patients with increased Qalb. Qalb elevation was an independent prognostic indicator for a poor prognosis in NSAE.

Critical care management of meningitis and encephalitis: an update

PURPOSE OF REVIEW

Meningitis and encephalitis represent severe neurological syndromes associated with encephalopathy, seizures, focal deficits, and neurological sequelae in survivors. We update on the critical care management of adult patients with severe meningitis and encephalitis.

RECENT FINDINGS

Large multicenter studies conducted in the adult population improved current knowledge on the epidemiology and outcomes of patients with severe meningitis and encephalitis. An early multimodal diagnostic workup (including CSF analysis, brain MRI, EEG, and serum studies) is mandatory for diagnosis and prognostication in those patients.New diagnostic methods, including multiplex PCR and next-generation sequencing techniques, allow for a faster differential diagnosis of infectious causes that may require specific antimicrobial therapy. Autoimmune causes of encephalitis, which may require urgent immunotherapy, are also increasingly recognized in the ICU setting. Although observational data suggest that early combined immunotherapy is associated with better neurological outcomes in patients with autoimmune encephalitis, randomized clinical trials have yet to be performed.

SUMMARY

Our review highlights the importance of an early multimodal approach for diagnosing severe meningitis and encephalitis. Randomized clinical trials are needed to identify pharmacological interventions that may improve patients' outcomes.