Anti-N-methyl-d-aspartate Receptor Encephalitis Related Sinus Node Dysfunction and the Lock-Step Phenomenon

Abstract

Described in 2007, anti-N-methyl-d-aspartate receptor encephalitis (ANMDARE) is a rare autoimmune limbic encephalitis affecting young adults (predominantly women of reproductive age) and is a paraneoplastic manifestation of ovarian teratoma in about half of the cases. ANMDARE is characterized by psychiatric changes, neurological changes, autonomic instability and cardiac dysrhythmias. In this report, we present a 36-year-old woman who was 16 weeks pregnant and brought to the hospital with confusion and subsequently had a seizure with Electroencephalography (EEG) demonstrated an extreme delta brush pattern consistent with ANMDARE. Patient developed sinus nodal dysfunction and was also found to have ovarian teratoma, a rather typical presentation for ANMDARE, that is considered a paraneoplastic syndrome for ovarian teratoma. In this report, we highlight the cardiac manifestation of ANMDARE, the pathophysiology associated with autonomic instability, and management strategies of this rare, and largely devastating illness.

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

“…The main clinical manifestations of patients with anti‐NMDAR encephalitis are psychobehavioral abnormalities, epilepsy, autonomic dysfunction, and so on. Very few patients may also have atypical manifestations such as cardiac arrhythmias, 4,27 meningitis, 28 and neurogenic bladder 29 …”

“…In adults, NR2A is found in most brain regions, NR2B in the hippocampus and forebrain, NR2C in cerebellum, and NR2D in limited subsets of neurons 3 . Anti‐NMDAR encephalitis is an autoimmune encephalitis mediated by anti‐NMDAR antibodies, which commonly occurs in children and young adults, with an incidence of about 5–8 per 100 000, and the incidence in women is four times higher than that in men 4 . Approximately 70% of all patients diagnosed with anti‐NMDAR encephalitis exhibit neuropsychiatric symptoms and movement disorders, with most patients having more severe clinical manifestations within a few weeks after the initial onset of psychiatric symptoms, including seizures, abnormal movements, decreased level of consciousness, autonomic dysfunction, or central hypoventilation, which will eventually lead to death if no timely and effective intervention is provided 5 …”