# Syncope in AQP4-IgG-positive neuromyelitis optica spectrum disorder: a case series and literature review

## TL;DR

This paper reports cases of a rare neurological disorder where patients experience fainting and highlights the importance of early diagnosis and treatment.

## Contribution

The study identifies syncope as a potential underrecognized symptom in AQP4-IgG-positive NMOSD and emphasizes the need for cardiac screening.

## Key findings

- Syncope can occur in AQP4-IgG-positive NMOSD patients with area postrema syndrome.
- MRI showed medulla oblongata lesions in all reviewed cases.
- Cardiac interventions were effective in 75% of patients with sinus arrest.

## Abstract

To report two cases of aquaporin-4 immunoglobulin G (AQP4-IgG)-positive neuromyelitis optica spectrum disorder (NMOSD) with syncope and to review previously documented cases, aiming to enhance recognition of this neurological manifestation and guide timely intervention.

We reported two NMOSD cases presenting with syncope. A literature search was conducted in PubMed using Medical Subject Headings (MeSH) and relevant keywords related to NMOSD, area postrema syndrome, and syncope.

The two patients, a 40-year-old man and a 41-year-old woman, presented with area postrema syndrome (APS) and recurrent syncope. The syncope attacks were transient, characterized by sudden loss of consciousness and spontaneous recovery. Electrocardiograms on admission were unremarkable in both cases. MRI showed dorsal medullary oblongata lesions. Both were treated with high-dose intravenous methylprednisolone followed by maintenance inebilizumab, leading to complete clinical remission, seroconversion to AQP4-IgG negativity, and an Expanded Disability Status Scale (EDSS) score of 0 at last follow-up. Besides, a total of 16 cases were identified and reviewed in this study, including our cases. The cohort showed equal sex distribution (male-to-female ratio 1:1) and a mean age of 53.94 years. All patients presented with APS preceding syncope, and neuroimaging revealed medulla oblongata lesions. Electrocardiographic abnormalities were documented in eight patients, all presenting with sinus arrest. Considering the possible mechanisms of syncope in these patients, eight patients had sinus arrest, two had orthostatic hypotension, and two experienced cardiorespiratory arrest. Among the eight patients with sinus arrest, six underwent cardiac interventions (75%): TPM implantation in four (one also undergoing cardioneuroablation) and PPM implantation in two. Two patients (25%) achieved remission with IVMP alone without cardiac intervention. All 16 patients remained free of syncope during follow-up.

Syncope may be an underrecognized manifestation of AQP4-IgG-positive NMOSD. Patients presenting with APS should be screened for syncope attacks, which may require emergency pacemaker implantation.