[Clinical analysis of relapsing anti-N-methyl-D-aspartate receptor encephalitis]

With the discovery of more patients with anti-N-methyl-D-aspartate (anti- NMDAR) encephalitis, frequent clinical relapses pose a new challenge to neurologists.

Retrospective reviews were conducted for 16 hospitalized patients with relapsing anti-NMDAR encephalitis at our hospital from June 2011 until November 2014. Their clinical data including symptoms, cerebrospinal fluid (CSF) profiles, neuroimaging findings and relapsing treatment were compared with those initial episodes.

There were 11 females and 5 males with a mean onset time of 21.2 (10-34) years. For initial episodes, the mean number of major symptoms was 5. 8 and the mean modified Rankin score (mRS) 4.56. And 7 (43.8%) cases were admitted into intensive care unit (ICU). All received first-line immunotherapy and only one case second-line immunotherapy. Ovarian teratoma was detected and resected in only one case of initial episode. Among 32 relapses, 8 cases (50% ) had multiple (2-4) relapses. There was a median delay of 5.0 (0.5-18) months for relapses. Relapses were common upon pausing or reducing immunotherapy, usually monotherapy with corticosteroids. Compared with initial episodes, relapses were less severe (mean mRS 2.69, mean number of symptom 2.59) and only 2 cases were admitted into ICU during relapses. Presentation of relapses were partial symptoms of initial episode. However, two patients had new symptoms of brain stem involvement. Brain magnetic resonance imaging (MRI) of 8 cases showed abnormality initially during initial episode and disappearance at relapses while new lesions appeared in 7 patients including 3 cases with CNS demyelinating features of central nervous system ( CNS) on MRI. The positivity rate of anti-NMDAR antibody was 100% in CSF and 53.1% in sera during relapses. Anti-AQP4 and NMO-Ig were positive in one case with brain stem involvement. All cases received first-line immunotherapy and 12 chronic second-line immunotherapy. Two cases of ovarian teratoma were detected on reassessment during relapse and then resected.

Inadequacy of second-line and chronic immunotherapy, occult teratoma and potential demyelination may contribute to a relapse of anti-NMDAR encephalitis. And its proper management should follow the recommendations of guidelines.