ANTI-NMDA RECEPTOR ENCEPHALITIS: A DIAGNOSTIC CHALLENGE FOR THE INTERNIST

Abstract

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Anti-N-methyl-D-aspartate receptor (NMDA-R) encephalitis is an autoimmune disease with a multifaceted presentation that involves memory deficits, psychiatric symptoms and autonomic instability. CASE PRESENTATION: We report a case of a 42 years old female who presented in the Emergency Room with a constellation of behavioral symptoms, delirium, body stiffness and fever for 1 week. Her past history was significant for seizures two years back, managed with valproic acid 500 mg BID and levetiracetam 500 mg BID. Glasgow Coma Scale (GCS) at the time of presentation was 9/15, which rapidly dropped to 3/15 without clinically observed seizures. The patient was intubated and admitted to the intensive care unit. Physical and neurological examination showed generalized dystonia, neck stiffness, 3/5 power in upper limbs and 2/5 in lower limbs. Cerebrospinal fluid (CSF) analysis was significant for lymphocytic pleocytosis which given the clinical presentation was consistent with the diagnosis of viral encephalitis. Initial treatment with ceftriaxone, acyclovir and dexamethasone was started. Computed tomography (CT) scan of the brain was normal. An electroencephalogram (EEG) revealed moderate to severe diffuse encephalopathy. During the hospital stay, she developed worsening orofacial rhythmic dyskinetic movements and autonomic dysfunction. GCS remained low even after initial management for viral encephalitis. Given the predominant symptoms of psychiatric, autonomic and dyskinetic features, further evaluation for an underlying autoimmune etiology was done. As a result, NMDA-R antibodies were positive. Steroids were administered and GCS improved after four sessions of plasmapheresis. Referral to an outside facility was made where she died after 4 days. The cause of her terminal events could not be established. DISCUSSION: Anti NMDA-R presents with combination of motor symptoms, speech disorder, seizures, decreased level of consciousness, behavioral and cognitive problems that usually prevail in earlier stages of disease. These symptoms steer patients to receive psychiatric evaluation first, often leading to late diagnosis and therapy. Anti NMDA-R encephalitis is a potentially treatable disease if diagnosed earlier and treated alone or combination therapy of plasmapheresis, intravenous immunoglobulins, pulsed steroids and immunosupressives. The internist should consider immediate screening for NMDA-R antibodies in a patient with new onset psychosis, evidence of encephalitis, neurological symptoms and abnormal or non-specific EEG, CSF or MRI manifestations. CONCLUSIONS: Early diagnosis and prompt initiation of treatment can potentially limit the worsening of psychiatric and neurological symptoms over the course of the disease and in our patient may have led to a better outcome. Reference #1: Kayser MS, Titulaer MJ, Gresa-Arribas N, Dalmau J: Frequency andcharacteristics of isolated psychiatric episodes in anti-N-methyl-D-aspartate receptor encephalitis. JAMA Neurol. 2013 DISCLOSURES: No relevant relationships by Fariha Ilyas, source=Web Response No relevant relationships by Maheen Ilyas, source=Web Response No relevant relationships by Mahnoor Khalid, source=Web Response No relevant relationships by Abdul Mannan Khan Minhas, source=Web Response No relevant relationships by Ahmed Qavi, source=Web Response