Olfactory dysfunction after autoimmune encephalitis depending on the antibody type and limbic MRI pathologies

Frontiers in Neurology

Neurology

Heinz Reichmann¹  Henning Schmitz-Peiffer¹  Martin Hänsel²  Hauke Schneider³  Antje Hähner⁴ 

[1] Department of Neurology, University of Dresden, Dresden, Germany;Department of Neurology, University of Dresden, Dresden, Germany;Department of Internal Medicine, GZO – Zurich Regional Health Center, Wetzikon, Switzerland;Department of Neurology, University of Dresden, Dresden, Germany;Department of Neurology, Augsburg University Hospital, Augsburg, Germany;Smell and Taste Clinic, Department of Otorhinolaryngology, Medical Faculty Carl-Gustav Carus, Technical University of Dresden, Dresden, Germany;

关键词: autoimmune encephalitis;    olfaction;    olfactory dysfunction;    threshold discrimination identification test;    NMDAR;    GAD;    LGI1;    Caspr2;   

DOI  :  10.3389/fneur.2023.1225975

 received in 2023-05-20, accepted in 2023-08-01,  发布年份 2023

来源: Frontiers

【 摘 要 】

ObjectivePatients’ olfactory function after autoimmune encephalitis (AE) involving limbic structures may be impaired. This study aimed to characterize olfactory function in patients after autoimmune encephalitides.MethodsA case–control study was performed including 11 AE patients with antibodies against NMDAR (n = 4), GAD (n = 3), VGKC (n = 3) and antibody-negative AE (n = 1) and a control group of 12 patients with pneumococcal meningo-encephalitis (PC). In subgroup analyses, AE patients with and without NMDAR-antibodies were compared. Olfactory function was assessed using the Sniffin Sticks test and the resulting TDI-score (threshold, discrimination, identification). Involvement of limbic structures was evaluated on imaging data (MRI). Statistical analyses were performed to test for correlations of TDI-score and MRI results.ResultsThe overall olfactory function of the AE-group and the PC-group was comparable (mean TDI 32.0 [CI 27.3–36.7], 32.3 [CI 28.5–36.0)]. The proportions of hyposmic patients were similar compared to the general population. However, AE patients of the non-NMDAR group had significantly lower TDI-scores (28.9 ± 6,8) than NMDAR patients (37.4 ± 3.5) (p = 0.046) and a significantly lower discrimination capability than the NMDAR patients (9.9 ± 2.0 vs. 14.5 ± 0.6) (p = 0.002). The non-NMDAR patients had significantly more limbic MRI pathologies (6/7) compared to the NMDAR patients (0/4) (p = 0.015). Furthermore, a correlation between limbic MRI pathologies and worse capability of smelling discrimination was found (p = 0.016, r = −0.704, n = 11).ConclusionOur results indicate that patients with NMDAR autoimmune encephalitis have normal long term olfactory function. However, patients with non-NMDAR autoimmune encephalitis appear to have a persistently impaired olfactory function, probably mediated by encephalitic damage to limbic structures.

【 授权许可】

Unknown   
Copyright © 2023 Hänsel, Schmitz-Peiffer, Hähner, Reichmann and Schneider.