Not Your Average Seizure: A Case of N-Methyl-D-Aspartate Receptor Encephalitis and Review of Literature

Abstract

Encephalitis is an inflammatory process of the brain that is most commonly related to infectious etiology; nonetheless, autoimmune encephalitis has been an increasingly identified entity that can cause it as well and should be considered. N-methyl-D-aspartate (NMDA) receptor encephalitis is a recently identified process but remains less recognized than autoimmune encephalitis. We report a case of an 18-year old female who initially presented with seizures and later developed behavioral symptoms of agitation, crying, screaming, and emotional lability. Ultimately, she was found to have NMDA receptor encephalitis related to ovarian paraneoplastic teratoma. The patient was treated with anti-epileptics and intravenous immunoglobulin and underwent oophorectomy that lead to her recovery. This case highlights the importance of early recognition of NMDA receptor encephalitis to facilitate appropriate investigations and management.

Clinical Reasoning: A Young Adult With New Seizures and Chapeau de Gendarme

“…9 The CSF WBC count is elevated in approximately half of the patients with anti-NMDAR encephalitis within 1 week of symptom onset and has been elevated in other case reports of anti-NMDAR encephalitis presenting with seizures. 10,11…”

Research progress in teratoma‐associated anti‐N‐methyl‐D‐aspartate receptor encephalitis: The gynecological perspective

“…33 As most patients are initially treated for infectious causes, neuropsychiatric sequelae become a potentially important issue. 34 In 2016, Graus et al 35 developed a set of diagnostic criteria with high sensitivity and specificity, which have also been confirmed in subsequent clinical applications, and the following three conditions need to be met for a confirmed diagnosis of anti-NMDAR encephalitis: (1) the presence of one or more of the following symptoms: mental abnormalities or cognitive dysfunction, language dysfunction, seizures, movement disorders, decreased level of consciousness, autonomic dysfunction, or central hyperventilation;…”

“…The EEG of up to 96% of patients with anti-NMDAR encephalitis can show nonspecific widespread diffuse slowing with epileptic focal activity, and in 13%-58% of these cases the EEG can show a delta brush, a delta wave background with a specific frequency of beta waves superimposed, which is neither sensitive nor specific for anti-NMDAR encephalitis, although it is a unique EEG pattern. 32,34 Imaging On magnetic resonance imaging (MRI) images of the brain, abnormalities are preferentially seen in fluidattenuated inversion recovery sequences, including high signal in the bilateral temporal lobe, frontal lobe, subcortical white matter, and periventricular regions; they may also show contrast enhancement in the soft meninges and cortex. Although the majority of anti-NMDAR encephalitis patients with abnormalities on cranial computed tomography (CT) or MRI are usually nonspecific, imaging is significant in screening for ovarian teratomas.…”

“…Although most patients with anti‐NMDAR encephalitis start with prodromal symptoms, previous studies have described a purely psychotic form of illness resembling schizophrenia, and the presence of acute psychotic symptoms or unexplained behavioral problems in young female patients may be the only first symptom of this rare teratoma causing anti‐NMDAR encephalitis 33 . As most patients are initially treated for infectious causes, neuropsychiatric sequelae become a potentially important issue 34 …”

“…The EEG of up to 96% of patients with anti‐NMDAR encephalitis can show nonspecific widespread diffuse slowing with epileptic focal activity, and in 13%–58% of these cases the EEG can show a delta brush, a delta wave background with a specific frequency of beta waves superimposed, which is neither sensitive nor specific for anti‐NMDAR encephalitis, although it is a unique EEG pattern 32,34 …”