Anti-N-Methyl-d-Aspartate (NMDA) Receptor Encephalitis Mimicking a Primary Psychiatric Disorder in an Adolescent

Abstract

Anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis likely has a wider clinical spectrum than previously recognized. This article reports a previously healthy 16-year-old girl who was diagnosed with anti-NMDA receptor encephalitis 3 months after onset of severe depression with psychotic features. She had no neurological manifestations, and cerebral magnetic resonance imaging (MRI) was normal. Slow background on electroencephalogram and an oligoclonal band in the cerebrospinal fluid prompted the search for anti-NMDA receptor antibodies. She markedly improved over time but remained with mild neuropsychological sequelae after a trial of late immunotherapy. Only a high index of suspicion enables recognition of the milder forms of the disease masquerading as primary psychiatric disorders.

Autoimmune limbic encephalitis presenting as relapsing psychosis

“…This cohort often present with an abrupt or acute onset of psychosis or behavioural change accompanied by memory impairment, mutism or insomnia which may serve as early clues of the underlying diagnosis 2 36 39 40. These initial symptoms are consistent with the known distribution and hypofunction of NR1/NR2 NMDAR in the basal forebrain, limbic system and hypothalamus 24.…”

Neuropsychological Profile of Anti-NMDA Receptor Encephalitis

“…Anti-NMDA receptor encephalitis belongs to the group known as paraneoplastic neurological syndromes, which are a rare and heterogeneous group of diseases that can affect any area of the nervous system having in common their association with cancer (often hidden in the time of clinical onset) and a likely autoimmune pathogenesis (Rosenfeld, 2011). Specifically, the anti-NMDA antibodies associated with different types of extra-limbic encephalitis and limbic structures has recently partnered with a neurological syndrome characterized by disturbances of consciousness, involuntary movements and seizures (Dalmau, 2008;Lebon, 2012;Waas, 2012). It is considered as a paraneoplastic syndrome associated primarily with ovarian tumors in young women, but can occur in the absence of neoplasia.…”

Schizophrenia as a diagnosis of exclusion

“…The brain-disease view is reflected in the dominant academic / professional discourse. Frequent use of confusing expressions such as conditions "mimicking" psychiatric disorders is one example from text-books and articles (33,34). "Mimicry" must, by definition, be attributed to the disorder for which evidence to validity is weaker.…”