Gait Disturbance as the Presenting Symptom in Young Children With Anti-NMDA Receptor Encephalitis

Abstract

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is one of the most common causes of encephalitis in children, more common than any of the viral encephalitides 1 and the second most common autoimmune cause after acute disseminated encephalomyelitis. 2 This neurologic disorder was first described in 2005 in young women who presented with psychiatric symptoms, seizures, encephalopathy, movement disorders, and autonomic instability and who were found to have ovarian teratomas. 3 Common antibodies that react against the NR1 subunit of the N-methyl-D-aspartate receptor were demonstrated to play a pathogenic role in this disease. 4 Since that time, descriptions of symptom onset, treatment, and outcome in larger cohorts have been published, and the condition has become notable for its dramatic clinical presentation with typically favorable response to therapy. More recently, the heterogeneity abstract This case series demonstrates a novel clinical phenotype of gait disturbance as an initial symptom in children <3 years old with anti-N-methyl-Daspartate receptor (anti-NMDAR) encephalitis. Anti-NMDAR encephalitis is one of the most common causes of encephalitis in children, more common than any of the viral encephalitides and the second most common autoimmune cause after acute disseminated encephalomyelitis. Anti-NMDAR encephalitis in children often presents with disrupted speech and sleep patterns followed by progression to motor dysfunction, dyskinesias, and seizures. Because this condition can present initially with vague symptoms, diagnosis and treatment of anti-NMDAR encephalitis are often delayed. Although nearly 40% of all reported patients are <18 years old, few infants and toddlers have been reported with this disease. Four children <3 years old were diagnosed with anti-NMDAR encephalitis at our institution. Interestingly, each child presented initially with the chief concern of gait disturbance. One child presented with unsteady walking and slurred speech, suggestive of cerebellar ataxia, and 3 had inability to bear weight on a unilateral lower extremity, resulting in unsteady gait. Two of these children had seizures at the time of hospital presentation. All developed classic behavioral changes, insomnia, dyskinesias, or decreased speech immediately before or during hospitalization. When seen in the setting of other neurologic abnormalities, gait disturbance should raise the concern for anti-NMDAR encephalitis in young children. The differential diagnosis for gait disturbance in toddlers and key features suggestive of anti-NMDAR encephalitis are reviewed.

Catatonia secondary to anti-N-methyl-D-aspartate receptor (NMDAr) encephalitis: a review

“…Studies have shown that children tend to have neurological symptoms more frequently 82 as opposed to psychiatric ones, and appear to have a higher incidence of movement disorders, with numbers of children noted to have a movement disorder ranging from 60% 83 to 90%, 84,85 which included unilateral dystonia, speech disturbance, status epilepticus, 78 and gait disturbances. 86 Granata et al 87 compared the movement disorders in children and teenagers (>12 years of age) with anti-NMDAr encephalitis and found that catatonic symptoms were much more prevalent in adolescents than in children, as other studies 88 had shown before. In children, especially those under 12, behavioral changes may present themselves with increased temper tantrums, hyperactivity, or irritability as opposed to frank psychosis.…”

Pediatric freezing of gait caused by anti‐NMDAR encephalitis

“…Anti‐NMDAR encephalitis constitutes one of the most common causes of encephalitis in children, in whom it can present with a broad spectrum of movement disorders . Gait disorders have been reported particularly in children, also as a presenting sign, and have been characterized by the presence of ataxia, unilateral weakness with circumduction or spasticity . Our case presented the typical sequence effect of step length noted in adults with FOG and probably represents the youngest case of such phenomena …”

Hemiataxia: A Novel Presentation of Anti-NMDA Receptor Antibody Mediated Encephalitis in an Adolescent

“…Tumor as a substrate for a paraneoplastic etiology is not uncommon [ 8 ]. As awareness of the condition has grown, a broadening of the phenotype has become evident, associated in some with seizures and gait disturbances [ 9 , 10 ]. Importantly, a growing number of movement disorders have been identified as well [ 4 , 10 – 12 ].…”

“…As awareness of the condition has grown, a broadening of the phenotype has become evident, associated in some with seizures and gait disturbances [ 9 , 10 ]. Importantly, a growing number of movement disorders have been identified as well [ 4 , 10 – 12 ]. Our patient's initial presentation with new-onset “tremor” in association with psychiatric decline is characteristic in that there was a clear association with movement phenomenon and neurobehavioral deterioration.…”