N-methyl D-aspartate receptor (NMDA-R) encephalitis is an autoimmune reaction towards subunits of NMDA-Rs located in the brain. Most patients are young female adults but it can occur in men.
Symptoms of NMDA-R encephalitis vary greatly but patients often present with acute central (psychosis, catatonia, seizures, memory deficit, dyskinesias, speech problems) and peripheral (breathing dysregulation) problems. These symptoms may also been seen in a number of psychiatric conditions that can delay diagnosis.
The definitive diagnosis of NMDA-R encephalitis is made by the presence of NMDA-R antibodies in cerebrospinal fluid. Once diagnosed, treatment can include prednisone, plasmapheresis, IV immunoglobulin, and/or tumor removal (in the case of females with tumors in their ovaries). While this is a very serious—and sometimes lethal—condition, most patients make a full recover from the episode.
An interesting study involving the diagnosis of NMDA-R encephalitis was undertaken by Singh et al who looked at data from the national Veteran Affairs (VA) population. Since the symptoms of this rare condition could be mistaken or masked by other conditions more common to veterans (ie, post traumatic stress disorder), the researchers sought out to determine how frequently NMDA-R encephalitis was diagnosed in this population.
A retrospective chart review was conducted for all patients within the VA over a 5 year period (Oct 1 2008 - Sept 30th 2013). This search identified 3 male patients with confirmed NMDA-R encephalitis. All 3 patients were diagnosed and managed for their NMDA-R encephalitis at a non-VA facility and later transferred to the VA for ongoing care. None had a malignancy, and all 3 were living at last follow up.
The authors concluded that the VA population—with its high proportion of male patients as well as patients with post traumatic stress disorder—may make it more challenging for clinicians to consider NMDA-R encephalitis as a possible diagnosis.
Singh G, Lott E, Greenlee J, Clardy S. NMDA Receptor Encephalitis in Veterans. Presented at American Academy of Neurology 67th Annual Meeting; April 18-25, 2015; Washington, DC. Abstract P1.103.