Seasonal variation in relapse of neuromyelitis optica spectrum disorders: A retrospective study in China

Clinical analysis of neuromyelitis optica spectrum disease with area postrema syndrome as the initial symptom

OBJECTIVE

The objective of this study was to report and discuss clinical analysis, including the diagnosis and treatment of 4 cases of neuromyelitis optica spectrum disease (NMOSD) with area postrema syndrome (APS) as the first symptom.

METHODS

Four patients with intractable nausea, vomiting, and confirmed NMOSD were included in the final analysis. All of these patients were initially misdiagnosed and mismanaged.

RESULTS

Among the 4 patients, 3 were admitted to the department of gastroenterology at the onset of the disease, and 2 were not correctly diagnosed and treated promptly due to misdiagnosis. Therefore, their symptoms worsened, and they were transferred to Intensive Care Unit (ICU) for life support. No obvious early medulla lesions were found in one patient. One patient was treated with intravenous immunoglobulin, methylprednisolone, and plasma exchange, but there was no significant clinical improvement, after which the disease relapsed during the treatment with low-dose rituximab.

CONCLUSION

The clinical manifestations of NMOSD are complex and diverse, and the initial symptoms, onset age of the patient, and magnetic resonance imaging (MRI) findings can influence the final diagnosis. Early identification of the APS and timely therapy can prevent visual and physical disabilities, even respiratory failure, coma, and cardiac arrest. Therefore, it is necessary to identify specific and sensitive serum and imaging markers for predicting the prognosis and recurrence of the disease.

Seasonal variation in attacks of neuromyelitis optica spectrum disorders and multiple sclerosis: Evaluation of 794 attacks from a nationwide registry in Argentina

BACKGROUND

Identification of triggers that potentially instigate attacks in neuromyelitis optica spectrum disorders (NMOSD) and multiple sclerosis (MS) has remained challenging. We aimed to analyze the seasonality of NMOSD and MS attacks in an Argentinean cohort seeking differences between the two disorders.

METHODS

A retrospective study was conducted in a cohort of NMOSD and MS patients followed in specialized centers from Argentina and enrolled in RelevarEM, a nationwide, longitudinal, observational, non-mandatory registry of MS/NMOSD patients. Patients with complete relapse data (date, month and year) at onset and during follow-up were included. Attack counts were analyzed by month using a Poisson regression model with the median monthly attack count used as reference.

RESULTS

A total of 551 patients (431 MS and 120 NMOSD), experiencing 236 NMOSD-related attacks and 558 MS-related attacks were enrolled. The mean age at disease onset in NMOSD was 39.5 ± 5.8 vs. 31.2 ± 9.6 years in MS (p < 0.01). Mean follow-up time was 6.1 ± 3.0 vs. 7.4 ± 2.4 years (p < 0.01), respectively. Most of the included patients were female in both groups (79% vs. 60%, p < 0.01). We found a peak of number of attacks in June (NMOSD: 28 attacks (11.8%) vs MS: 33 attacks (5.9%), incidence rate ratio 1.82, 95%CI 1.15-2.12, p = 0.03), but no differences were found across the months in both disorders when evaluated separately. Strikingly, we observed a significant difference in the incidence rate ratio of attacks during the winter season when comparing NMOSD vs. MS (NMOSD: 75 attacks (31.7%) vs MS: 96 attacks (17.2%), incidence rate ratio 1.82, 95%CI 1.21-2.01, p = 0.02) after applying Poisson regression model. Similar results were observed when comparing the seropositive NMOSD (n = 75) subgroup vs. MS.

CONCLUSIONS

Lack of seasonal variation in MS and NMOSD attacks was observed when evaluated separately. Future epidemiological studies about the effect of different environmental factors on MS and NMOSD attacks should be evaluated prospectively in Latin America population.

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

OBJECTIVE

The aim of this study was to examine the seasonal distribution in clinical onset of autoimmune encephalitis (AE) in a multi-center cohort in China.

METHODS

This retrospective study consecutively recruited patients with new-onset definite neuronal surface antibody-associated AE between January 2015 and December 2020 from 3 tertiary hospitals. Demographic and clinical characteristics of the participants were comprehensively collected. Statistical analyses were performed using R.

RESULTS

Of the 184 patients of AE in our database, 149 (81.0%) were included in the final analysis. The median age of onset was 40.0 years, and 66 (44.3%) patients were female. AE predominantly started in autumn (47, 31.5%) and summer (43, 28.9%) months. Summer-autumn predominance of the clinical onsets was also present in the anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis group (54, 60.0%) and anti-leucine-rich glioma inactivated 1 (LGI1) encephalitis group (20, 76.9%). No obvious seasonal variations were observed among gender, onset age, disease duration, prodromal symptoms, clinical type of initial symptoms, and disease severity by the time of admission.

CONCLUSION

This study suggested summer-autumn predominance of the clinical onsets in patients with AE, especially anti-NMDAR and anti-LGI1 encephalitis. Therefore, clinicians should have a high index of suspicion for AE in encephalopathy patients in summer and autumn period.

Seasonal variation of onset in patients with anti-aquaporin-4 antibodies and anti-myelin oligodendrocyte glycoprotein antibody

This study aimed to determine the seasonal impact on the clinical onset of inflammatory neurological diseases of the central nervous system by analyzing the onset month with information on clinical manifestations in Japanese patients. As a result, patients with anti-aquaporin-4 antibodies (AQP4-IgG)-positive neuromyelitis optica spectrum disorders (NMOSD) showed spring-summer predominance of the clinical onset. Conversely, patients with anti-myelin oligodendrocyte glycoprotein antibody (MOG-IgG)-associated disease showed autumn-winter predominance of the clinical onset. Both seasonal variations were irrespective of the clinical manifestation. Environmental factors with seasonal variation influence the development of neurological conditions related to AQP4-IgG and MOG-IgG.