Long-term persistence of NMDAR antibodies after encephalitis with de novo occurrence of demyelinating disorder

A case report of lymphoproliferative disease in brain following therapies with mycophenolate Mofetil and Fingolimod and literature review

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder. With the method of indirect immunofluorescence assay (IIF), more anti-NMDAR encephalitis patients have been discovered when its first onset. But it was rare that anti-NMDAR encephalitis overlapped with multiple sclerosis (MS) documented in literatures. Here, we present a case who initially developed anti-NMDAR encephalitis and MS. Furthermore, we concluded the characteristics of patients who were diagnosed as anti-NMDAR encephalitis overlapping with MS. Additionally, due to the relapsing process, mycophenolate mofetil and sequentially fingolimod for the treatment were taken, which subsequently led to the development of a lymphoproliferative disease in his brain and other organs. This case illustrates the complex role of immunosuppressive agents.

NMDAR autoimmune encephalitis and fulminant relapse of multiple sclerosis: a rare overlap syndrome

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disease that has been rarely associated with AQP4-IgG and MOG-IgG demyelinating diseases, and even more rarely with multiple sclerosis. We present the case of a woman in her 40s with confirmed NMDAR encephalitis and coexistent fulminant relapse of multiple sclerosis treated with alemtuzumab 6 years prior, who had a favourable outcome following treatment with ocrelizumab. We proceed to systematic review of similar reported cases, finding a lower than anticipated prevalence of underlying malignancy compared with isolated NMDAR encephalitis, in this rare overlap syndrome.

Glucocorticoid-dependent multiple sclerosis overlapping anti-NMDA receptor encephalitis: a case report and literature review update

BACKGROUND

Previous studies suggest a relationship between central nervous system inflammatory demyelinating diseases and anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. Also, the overlap between anti-NMDAR encephalitis and multiple sclerosis (MS) has been reported. However, the pathogenesis and clinical characteristics are still obscure.

CASE PRESENTATION

A 33-year-old woman presented with diplopia and sensory ataxia at the onset. The cerebrospinal fluid (CSF) anti-NMDAR antibodies were positive (1:3.2), and nuclear magnetic resonance imaging (MRI) showed bilateral centrum ovale and lateral ventricle demyelinating lesions. Therefore, she was diagnosed with anti-NMDAR encephalitis. After administering intravenous immunoglobulin and oral prednisone, her lesions disappeared, and symptoms were relieved. The condition was maintained with a low dose of prednisone, but her lesions reappeared on MRI. Consequently, immunomodulatory therapy of mycophenolate mofetil was initiated. However, she developed dysarthria and right limb ataxia after 10 months with a positive CSF anti-NMDAR antibody (1:1) and positive oligoclonal band. The MRI showed symmetrical multiple demyelinating lesions. Considering the MS diagnosis, her neurological dysfunction again improved significantly after intravenous methylprednisolone. Unfortunately, her symptoms aggravated for the second time when teriflunomide was started. Finally, her condition was controlled again with oral prednisone.

CONCLUSIONS

Consistent with previous cases of overlapping anti-NMDAR encephalitis and MS, patients often show atypical symptoms on MRIs and immunological tests. The overlap cannot be arbitrarily treated because of the recurrence of previous diseases. Long-term follow-up, dynamic antibody monitoring, and MRI examination are crucial for these patients. The special dependency of the patient on glucocorticoids in this study has been rarely reported, which may guide the treatment of insensitivity to disease-modifying therapy in recurrent overlapping anti-NMDAR encephalitis and MS.

Overlapping anti-NMDAR encephalitis and multiple sclerosis: A case report and literature review

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune-mediated disease characterized by complicated neuropsychiatric symptoms and the detection of cerebrospinal fluid antibodies against the GluN1 subunit of the NMDAR. With the proposed clinical method, more anti-NMDAR encephalitis patients have been discovered since its first report. However, anti-NMDAR encephalitis overlapping with multiple sclerosis (MS) is rare. Herein we report a male patient with anti-NMDAR encephalitis who developed MS in mainland China. Furthermore, we summarized the characteristics of patients who were diagnosed with overlapping MS and anti-NMDAR encephalitis in previous studies. Additionally, we pioneered the use of mycophenolate mofetil in immunosuppressive therapy, providing a novel therapeutic alternative for overlapping anti-NMDAR encephalitis and MS.

Clinical Characteristics of Anti-N-Methyl-d-Aspartate Receptor Encephalitis Overlapping with Demyelinating Diseases: A Review

Anti-N-methyl-d-aspartate receptor encephalitis (NMDARe), a common autoimmune encephalitis, can be accompanied by demyelinating disorders, including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). To compare the clinical characteristics of patients with different overlapping syndromes, we searched the PubMed database and performed a systematic review. Of the 79 patients with overlapping syndromes, 15 had MS, 18 had aquaporin-4-antibody-positive NMOSD (AQP4-Ab-positive NMOSD), and 46 had MOGAD. Compared with classical NMDARe, overlapping syndromes showed atypical symptoms, such as limb weakness, sensory disturbance, and visual impairments in addition to the main symptoms of NMDARe and a lower ratio of ovarian teratoma. Patients with MOGAD overlap were the youngest, while patients with MS and AQP4-Ab-positive NMOSD overlap tended to be older than patients with classical NMDARe. A majority of patients with NMDARe who overlapped with MS or AQP4-Ab-positive NMOSD were female, but this was not the case for patients overlapped with MOGAD. When NMDARe and demyelinating diseases occurred sequentially, the interval was the longest in patients with NMDARe overlapped with MS. A favorable outcome was observed in patients overlapping with MOGAD, but no robust comparison can be drawn with the patients overlapping with AQP4-Ab-positive NMOSD and MS regarding the small number of available data. The long-term prognosis of overlapping syndromes needs further investigation.

Neuropathological Variability within a Spectrum of NMDAR-Encephalitis

OBJECTIVE

To describe the neuropathological features of N-methyl-D-aspartate receptor (NMDAR)-encephalitis in an archival autopsy cohort.

METHODS

We examined four autopsies from patients with NMDAR-encephalitis; two patients were untreated, three had comorbidities: small cell lung cancer, brain post-transplant lymphoproliferative disease (PTLD), and overlapping demyelination.

RESULTS

The two untreated patients had inflammatory infiltrates predominantly composed of perivascular and parenchymal CD3+ /CD8- T cells and CD79a+ B cells/plasma cells in basal ganglia, amygdala, and hippocampus with surrounding white matter. The hippocampi showed a significant decrease of NMDAR-immunoreactivity that correlated with disease severity. The patient with NMDAR-encephalitis and immunosuppression for kidney transplantation developed a brain monomorphic PTLD. Inflammatory changes were compatible with NMDAR-encephalitis. Additionally, plasma cells accumulated in the vicinity of the necrotic tumor along with macrophages and activated microglia that strongly expressed pro-inflammatory activation markers HLA-DR, CD68, and IL18. The fourth patient developed demyelinating lesions in the setting of a relapse 4 years after NMDAR-encephalitis. These lesions exhibited the hallmarks of classic multiple sclerosis with radially expanding lesions and remyelinated shadow plaques without complement or immunoglobulin deposition, compatible with a pattern I demyelination.

INTERPRETATION

The topographic distribution of inflammation in patients with NMDAR-encephalitis reflects the clinical symptoms of movement disorders, abnormal behavior, and memory dysfunction with inflammation dominantly observed in basal ganglia, amygdala, and hippocampus, and loss of NMDAR-immunoreactivity correlates with disease severity. Co-occurring pathologies influence the spatial distribution, composition, and intensity of inflammation, which may modify patients' clinical presentation and outcome. ANN NEUROL 2021;90:725-737.