[Cognitive and psychiatric evolution in autoimmune encephalitis in a school-aged child: Clinical case].

Background: Autoimmune encephalitis (AE) is a rare entity in children and can manifest psychiatric symptoms without evident neurological signs. Clinic case: A 10-year-old female with a subacute case of 3 weeks of evolution, denotating disinhibition, behavioral errors, mood swings with irritability, auditory stimuli intolerance, restlessness in social situations; sleep cycle disturbances, right arm weakness upon physical exertion that progressed into right hemiparesis, adynamia, verbal apraxia, and agraphia. The patient was hospitalized, and infectious processes were excluded. Brain imaging with nuclear magnetic resonance showed lesions compatible with basal leptomeningitis. The electroencephalogram did not show cortical irritability. Suspecting an autoimmune etiology, the patient received therapy with immunomodulators, showing a gradual response without reaching to previous functionality state. Sertraline and second-generation antipsychotics were added, with the patient being discharged due to overall improvement. At 3 months of follow-up, the patient persisted with moderate cognitive impairment. Fifteen months after disease debut, the patient's cognitive status score was normal, with mild irritability, and continued avoidance of intense auditory stimuli and crowded places. Conclusions: AE diagnosis is challenging for pediatricians, as a high suspicion level is required when facing nonspecific symptoms; the prognosis depends on early identification and initiation of immunotherapy.