Clinical analysis of anti-NMDAR encephalitis combined with MOG antibody in children.

OBJECTIVE

To analyze the clinical features in children with anti-NMDAR encephalitis combined with myelin oligodendrocyte glycoprotein antibody (MOG ab).

METHODS

Clinical data of 7 children with anti-NMDAR encephalitis combined with MOG ab(+) were collected in Guangzhou Women and Children's Medical Center from January, 2016 to June, 2019. Children with NMDAR ab(+)/MOG ab(-) and MOG ab(+)/NMDAR ab(-) were randomly selected as controls.

RESULTS

Onset age was 6.0 (IQR 5.0-7.0) years old, male to female was 2:5. Prominent symptoms include abnormal mental behavior (7/7), sleep disorder (6/7), speech disorder (6/7), involuntary movement (4/7) and paralysis (4/7). There were significant differences between NMDAR ab(+)/MOG ab(+) group versus MOG ab(+)/NMDAR ab(-) and NMDAR ab(+)/MOG ab(-) group versus MOG ab(+)/NMDAR ab(-) group (P< 0.0167, Fisher exact tests) in abnormal mental behavior, sleep disorder, speech disorder and involuntary movement. 1 case developed anti-NMDAR encephalitis 1 year after recovery from MOG ab related acute disseminated encephalomyelitis (ADEM). 4 cases developed anti-NMDAR encephalitis and MOG ab related ADEM simultaneously, with 2 cases relapsed. 2 cases were anti-NMDAR encephalitis with only MOG ab positive. In terms of MRI, there were differences in subcortical white matter, basal ganglia and brainstem (P < 0.0167, Fisher exact tests) between NMDAR ab(+)/MOG ab(+) group versus NMDAR ab(+)/MOG ab(-) (P < 0.0001) and NMDAR ab(+)/MOG ab(-) group versus MOG ab(+)/NMDAR ab(-) group(P<0.0001). There were significant differences in MOG antibody titer (Z = -=2.03, P = 0.042) and duration (Z = -1.97, P = 0.049) between relapsed and non-relapsed patients. 3 cases had neurological sequelae. The differences of NMDAR antibody titer (Z = -2.22, P = 0.026) and duration (Z = -2.18, P = 0.029) were significant between patients with and without neurological sequelae.

CONCLUSION

NMDAR and MOG antibodies can coexist in children with autoimmune encephalitis. Double antibody positive subjects had more overlaps in clinical manifestations with NMDAR encephalitis, and more overlaps in MRI changes with MOG ab related disease. Higher persistent MOG antibody titer may indicate recurrence, while higher persistent NMDAR antibodies titer may cause neurological sequelae.