Objective: To analyze the clinical profile of patients with suspected autoimmune encephalitis.

Background: Autoimmune encephalitis (AE) is a disease characterized by a diverse range of clinical presentations caused by autoantibodies that remain partially unidentified and should be considered when a patient meets Graus’s criteria. The clinical symptoms described in the diagnostic criteria include behavioral changes, alterations in consciousness, and memory changes of subacute onset (defined as less than 3 months); however, even though movement disorders are a hallmark presentation, they were not included as specific criteria (1,2).

Method: This retrospective cohort study was conducted from 2018 to 2022 at Hospital Geral de Fortaleza, one of the centers participating in the Brazilian autoimmune encephalitis network in collaboration with the Medical University of Vienna. We analyzed autoantibodies in serum and cerebrospinal fluid (CSF) using tissue-based assays (TBA) to detect antineuronal autoantibodies. Positive TBA results prompted further testing with cell-based assays for specific surface antibodies. Statistical analyses were carried out using R Statistical Analysis Software, implementing the Shapiro-Wilk normality test and Pearson’s chi-squared test.

Results: It is noteworthy that among the 26 patients, 18 (69.23%) were women, with a median age of 34 years (IQR: 15-75). We identified 11 (42%) autoantibodies in CSF serum, including 6 (54.5%) Anti-NMDAR, 2 (18.2%) anti-AMPAR, 1 (9.1%) anti-LGI1 and 1 (9.1%) anti-titin. Among the various symptoms observed in the total study sample (table 1), movement disorder was the only one that showed statistical significance between individuals with positive and negative autoantibodies (p: 0.017). Anti-NMDAR antibodies were the most associated with movement disorders in autoimmune encephalitis in our sample. [Table 1, Table 2]. One of the antibodies identified in our center has not yet been described, and anti-titin remains uncertain as to whether it is merely a marker or pathogenic (4).

Conclusion: Our findings align with existing literature, showing that movement disorders are the most common in AE anti-NMDAR, particularly orofacial dyskinesia, followed by catatonia, chorea, dystonia, stereotyped movements, myoclonus, and tremor (2,5). Further studies are needed to determine if movements disorders should be considered a specific criterion when considering AE as a diagnosis.

Table 2 Types of Movement Disorders

Table 1 – AE with Positive AB and Negative AB

References: 1. GRAUS, F. et al. A clinical approach to diagnosis of autoimmune encephalitis. Lancet neurology, v. 15, n. 4, p. 391–404, 2016.
2. Dalmau, J., & Graus, F. (2023). Diagnostic criteria for autoimmune encephalitis: utility and pitfalls for antibody-negative disease. The Lancet. Neurology, 22(6), 529–540. https://doi.org/10.1016/S1474-4422(23)00083-2
3. DE FREITAS DIAS, B. et al. Brazilian autoimmune encephalitis network (BrAIN): antibody profile and clinical characteristics from a multicenter study. Frontiers in immunology, v. 14, p. 1256480, 2023.
4. YAO, Y. et al. Thymoma-associated autoimmune encephalitis with positive Titin antibodies: A case report. Journal of neuroimmunology, v. 358, n. 577670, p. 577670, 2021.
5. HONNORAT, J.; JOUBERT, B. Movement disorders in autoimmune encephalitis and paraneoplastic neurological syndromes. Revue neurologique, v. 174, n. 9, p. 597–607, 2018.

« Back to 2025 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/movement-disorders-in-autoimmune-encephalitis-a-cohort/