Anti-N-methyl-d-aspartate-receptor encephalitis in a patient with acute organic brain syndrome with catatonia

Case Report: Anti-N-methyl-d-aspartate (NMDA)-receptor (NMDAR)-encephalitis is a neuroautoimmune syndrome against NMDARs in the central nervous system (CNS) that affects mainly young women. First described in 2005, it was classified as a paraneoplastic syndrome in association with ovarian teratomas. In the meantime, a neurological autoimmune cause against a number of possible stimuli has been postulated.

In a video documentation, we present the case of an 18-year-old girl who suffered from severe cognitive impairments, such as hallucinations during her A-level examinations. She was admitted to hospital with suspected encephalitis 10 days after the onset of the symptoms, which became more pronounced over time and included catatonia with unresponsiveness, akinesia, and athetotic movements, as well as self-endangering and aggressive agitation. There was also a period of severe hypertension.

A pleocytosis was detected in the CNS, with intrathecal synthesis of immunoglobulin G as well as a mild increase of protein levels. The electroencephalography showed severe slowing, yet no epileptic potentials were observed. The cranial magnetic resonance tomography was pathological only after 1 month and displayed an alteration of the signals in the cerebellum. No ovarian tumor was found.

We started treatment with a first corticosteroid pulse, although NMDAR antibody levels were initially negative and increased only 40 days after the onset of the disease. Corticosteroid pulses were repeated four times, leading to improvements in vigilance, speech, and motoric abilities. Because antibody levels remained high, a therapy with monoclonal anti-CD20-antibodies (Rituximab) was initiated. This led to an almost complete recovery of our patient.

Conclusions: Anti-NMDAR-encephalitis is an important differential diagnosis in patients with acute organic brain syndrome, although antibody detection may be initially negative. Early diagnosis is paramount to make use of the available therapeutic options. The impressive reversal of the psychiatric symptoms is demonstrated through a video.