Case Report: Overlapping Syndrome of Anti-NMDAR Encephalitis and MOG Inflammatory Demyelinating Disease in a Patient With Human Herpesviruses 7 Infection

Abstract

Objectives: This study reported a case of overlapping anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis and myelin oligodendrocyte glycoprotein (MOG) inflammatory demyelinating disease with human herpesviruses 7 (HHV-7) infection.

Methods: The detailed clinical characteristics, neuroimaging features, and outcomes of the patient were collected. Polymerase chain reaction (PCR), cell-based assay (CBA) and the tissue-based indirect immunofluorescence assay (TBA) were used for diagnosis.

Results: The clinical manifestations included headache, dizziness, fever, optic neuritis, and epileptic-seizures. Brain magnetic resonance imaging (MRI) showed hyperintensities involving the left frontal, orbital gyrus and bilateral optic nerve with substantial contrast enhancement. Moreover, test for HHV-7 DNA by using the next generation sequencing metagenomics and polymerase chain reaction showed positive result in CSF but not in the serum samples. Anti-HHV-7 IgM and IgG antibodies were detected in both the serum and cerebrospinal fluid. NMDAR antibodies (1:10) were found positive in the patient's CSF by a cell-based assay, and MOG antibodies were positive in the serum (1:10) and CSF (1:32). The patient appeared to respond well to immune therapy and it was found that the clinical symptoms including epileptic-seizure as well as headache were relieved and cerebral lesions almost disappeared after the treatment. However, his vision was not completely restored even at the 8-month follow-up, especially the vision in his right eye which was more seriously damaged.

Discussion: We report a rare case of MOG antibodies and anti-NMDAR encephalitis overlapping syndrome (MNOS) with HHV-7 infection for the first time. The possibility of MNOS needs be considered when optic neuritis occurs in the patients diagnosed with anti-NMDAR encephalitis. Besides, immunotherapy should be initiated as early as possible to improve the treatment outcomes and facilitate complete cure.

Keywords: HHV-7 infections; MOG antibodies and NMDAR encephalitis overlapping syndrome (MNOS); anti-NMDAR encephalitis; case report; optic neuritis.

Figure 1

Brain MRI performance. (A–C) The MRI data of patient at two weeks after the symptom onset showed hyperintensity of the left frontal lobe on fluid-atten uated inversion recovery (FLAIR) imaging and T2-weighted imaging (arrows). (D–F) MRI of the brain was repeated at 6 weeks and showed enhancement of the left frontal lobe lesion involved the bilateral optic nerve (arrows) on FLAIR imaging conducted with gadolinium contrast. (G–I) Brain MRI scan performed at three months after initial symptom onset depicted a significant improvement of the imaging abnormality.

Figure 2

(A) Cerebrospinal fluid (CSF) showing the binding to the surface of the cells expressing anti-NMDAR receptors (NMDAR) (1:10) (scale bar 20μm). (B) Myelin oligodendrocyte glycoprotein (MOG) antibodies (1:32) were detected in the CSF (scale bar 100μm). (C) MOG antibodies (1:1) were detected in serum (scale bar 100mm). (D) GFAP antibodies were found negative in the CSF (scale bar 100mm).

Figure 3

Timeline with clinical manifestation, treatment progression and diagnosis time. EEG, Electroencephalograph; MRI, Magnetic Resonance Imaging; IVMP, Intravenous methylprednisolone; HHV-7, Human Herpesviruses-7; NMDAR, Anti-N-methyl-D-aspartate receptor; MOG, Myelin oligodendrocyte glycoprotein.