Partial Manifestation of Anti‐NMDA‐R Encephalitis with Predominant Movement Disorder

Abstract

Childhood anti–N‐methyl‐d‐aspartate receptor (NMDA‐R) antibody encephalitis is a well‐recognized autoimmune encephalitis presenting typically with a combination of varied movement disorders, seizures, mutism, behavioral and sleep disturbances, and autonomic changes. Monosymptomatic or incomplete forms of the disorder are rare, but have recently been reported. Here, we describe 2 children with nonparaneoplastic anti‐NMDA‐R encephalitis with partial presentation in the form of movement disorder and minor behavioral changes.

Rare Manifestation of Anti-Nmdar Encephalitis

“…Anti N-methyl-d-aspartate receptor (NMDAR) encephalitis was first described in young women, having an association with ovarian teratoma, in 2007. 5,6 It is an immune-mediated disease, developing auto-antibodies against NMDAR, a protein important for neuronal plasticity and memory function. 1 Gable et al described in their study that 65% of cases of Anti-NMDAR occur in ≤18 years.…”

Movement disorders with neuronal antibodies: syndromic approach, genetic parallels and pathophysiology

“…NMDAR-antibody encephalitis typically manifests in an age-dependent manner: adults tend to present with neuropsychiatric disturbance and behavioural problems initially, while in children, epilepsy and movement disorders, such as chorea, are more prominent. Children with NMDAR-antibody encephalitis may be misdiagnosed as having Sydenham’s chorea, particularly in early stages of the disease, as both disorders feature a subacute onset and prominent behavioural/neuropsychiatric disturbances ( Hacohen et al , 2014 ; Udani et al , 2016 ). Overall, isolated movement disorder presentations are, however, extremely rare in NMDAR-antibody-related encephalitis, and typically, the presence of seizures, dysautonomia, or ataxia should alert the neurologist to request testing for NMDAR antibodies ( Titulaer et al , 2013 ).…”

Association between clinical factors and orofacial dyskinesias in anti‐N‐methyl‐D‐aspartate receptor encephalitis

“…It is well established that MDs are a frequent symptom in anti‐NMDAR encephalitis and may be observed from the initial stages of disease to the comatose stage (Dalmau et al., 2011 ). MDs occur either in isolation or, more commonly, as a prominent feature of the condition and may appear as the first sign in children (Udani et al., 2015 ). Available evidence suggests that orofacial dyskinesias (OFLD) is a distinctive feature of MDs in anti‐NMDAR encephalitis, which usually appears during the phase of unresponsiveness and catatonia (Dash & Pandey, 2019 ; Duan et al., 2016 ).…”