A case report of anti-glutamic acid decarboxylase antibody-associated encephalitis presenting with stroke-like symptoms as the initial manifestation

doi:10.11958/20260849

Abstract

Abstract:

Anti-glutamic acid decarboxylase antibody-associated encephalitis is a rare and easily misdiagnosed autoimmune encephalitis with diverse clinical manifestations and lack of specificity. Currently, there are few clinical case reports related to this disease. Anti-glutamic acid decarboxylase antibody-associated encephalitis presenting with stroke-like symptoms as the initial manifestation is even rarer. This article presents a case of a 74-year-old female patient with acute stroke-like symptoms (slurred speech, weakness in the right limb) as the initial manifestation. She has a history of atrial fibrillation, hypertension and cerebral infarction. From the perspectives of clinical symptoms, imaging examination, laboratory tests and excluding other causes, analyses of anti-glutamic acid decarboxylase antibody-associated encephalitis suggest that for patients with stroke-like acute focal neurological deficits and atypical imaging (extramarginal lobe system), the possibility of autoimmune encephalitis should be considered, and antibody detection and immunotherapy should be performed as soon as possible.

Key words: glutamic acid decarboxylase, limbic encephalitis, antibody, stroke, autoimmune encephalitis

CLC Number:

R593.2

Figures/Tables 5

Fig.1 The brain MRI obtained on the first day of admission after intravenous thrombolysis of the patient

Fig.2 DWI sequence of brain MRI obtained on day 9 of admission of the patient

Fig.3 FLAIR sequence of brain MRI obtained on day 9 of admission of the patient

Fig.4 Electroencephalogram background and focal slow waves of the patient before immunotherapy

Fig.5 Anti-GAD65 IgG antibody fluorescence image of the patient (IIF, ×200)

References 31

[1]	黄梁江, 朱纪玲, 严雅维, 等. 自身免疫性脑炎的临床特点与预后分析[J]. 内科急危重症杂志, 2020, 26(1):29-33.
	Huang L J, Zhu J L, Yan Y W, et al. Clinical characteristics and outcome of patients with autoimmune encephalitis[J]. Journal of Critical Care in Internal Medicine, 2020, 26(1):29-33. doi:10.11768/nkjwzzzz20200108.
[2]	Dalmau J, Tüzün E, Wu H Y, et al. Paraneoplastic anti-N-methyl-D-aspartate receptor encephalitis associated with ovarian teratoma[J]. Ann Neurol, 2007, 61(1):25-36. doi: 10.1002/ana.21050.
[3]	熊震, 陈曼, 朱舟. 抗谷氨酸脱羧酶65抗体脑炎及相关自身免疫性多内分泌腺病综合征[J]. 内科急危重症杂志, 2023, 29(3):189-192.
	Xiong Z, Chen M, Zhu Z. Anti-glutamic acid decarboxylase 65 antibody-associated autoimmune encephalitis and associated autoimmune polyendocrinopathy syndrome[J]. Journal of Critical Care in Internal Medicine, 2023, 29(3):189-192. doi:10.11768/nkjwzzzz20230304.
[4]	中华医学会神经病学分会神经感染性疾病与脑脊液细胞学学组, 王佳伟, 关鸿志, 等. 中国自身免疫性脑炎诊治专家共识(2022年版)[J]. 中华神经科杂志, 2022, 55(9):931-949.
	Chinese Society of Neuroinfectious Diseases and Cerebrospinal Fluid Cytology, Wang J W, Guan H Z, et al. Chinese expert consensus on the diagnosis and management of autoimmune encephalitis(2022 edition)[J]. Chinese Journal of Neurology, 2022, 55(9):931-949. doi:10.3760/cma.j.cn113694-20220219-00118.
[5]	Erlander M G, Tillakaratne N J, Feldblum S, et al. Two genes encode distinct glutamate decarboxylases[J]. Neuron, 1991, 7(1):91-100. doi:10.1016/0896‑6273(91)90077‑d.
[6]	Ellis T M, Atkinson M A. The clinical significance of an autoimmune response against glutamic acid decarboxylase[J]. Nat Med, 1996, 2(2):148-153.
[7]	Gresa-Arribas N, Ariño H, Martínez-Hernández E, et al. Antibodies to inhibitory synaptic proteins in neurological syndromes associated with glutamic acid decarboxylase autoimmunity[J]. PLoS One, 2015, 10(3):e0121364. doi:10.1371/journal.pone.0121364.
[8]	Holmøy T, Skorstad G, Røste LS, et al. Stiff person syndrome associated with lower motor neuron disease and infiltration of cytotoxic T cells in the spinal cord[J]. Clin Neurol Neurosurg, 2009, 111(8):708-712. doi:10.1016/j.clineuro.2009.06.005.
[9]	Manto M U, Laute M A, Aguera M, et al. Effects of anti‑glutamic acid decarboxylase antibodies associated with neurological diseases[J]. Ann Neurol, 2007, 61(6):544-551. doi:10.1002/ana.21123.
[10]	Graus F, Saiz A, Dalmau J. GAD antibodies in neurological disorders-insights and challenges[J]. Nat Rev Neurol, 2020, 16(7):353-365. doi:10.1038/s41582‑020‑0359‑x.
[11]	Muñoz-Lopetegi A, de Bruijn M A A M, Boukhrissi S, et al. Neurologic syndromes related to anti-GAD65:Clinical and serologic response to treatment[J]. Neurol Neuroimmunol Neuroinflamm, 2020, 7(3):e696. doi:10.1212/NXI.0000000000000696.
[12]	Maiylova A, Nabiev S, Popova E, et al. Central positional vertigo at the onset of autoimmune encephalitis associated with antibodies to GAD65[J]. Cureus, 2025, 17(1):e77355. doi:10.7759/cureus.77355.
[13]	Dubey D, Pittock S J, Kelly C R, et al. Autoimmune encephalitis epidemiology and a comparison to infectious encephalitis[J]. Ann Neurol, 2018, 83(1):166-177. doi:10.1002/ana.25131.
[14]	李泰燕, 周少旦, 孔德燕, 等. 抗谷氨酸脱羧酶65抗体相关脑炎14例临床分析[J]. 中风与神经疾病杂志, 2024, 41(12):1106-1112.
	Li T Y, Zhou S D, Kong D Y, et al. Clinical features of 14 patients with anti-glutamic acid decarboxylase 65 encephalitis[J]. Journal of Apoplexy and Nervous Diseases, 2024, 41(12):1106-1112. doi:10.19845/j.cnki.zfysjjbzz.2024.0211.
[15]	Tantillo G, Abrams R, Mishra N, et al. Anti-GAD65 antibody:a possible link to encephalopathy,aphasia,seizures and lateralized weakness[J]. Neurology, 2019, 92(15_supplement):P2.2-021. doi:10.1212/WNL.92.15_sup-plement.P2.2-021.
[16]	Kuang Z, Baizabal-Carvallo J F, Alonso-Juarez M, et al. The limbic and extra-limbic encephalitis associated with glutamic acid decarboxylase(GAD)-65 antibodies:an observational study[J]. Neurol Sci, 2025, 46(6):2765-2777. doi:10.1007/s10072-024-07933-7.
[17]	Xia S Q, Fan H N, Fan L F, et al. Paraneoplastic anti-GAD65 extralimbic encephalitis presented with epilepsy:a case report[J]. Medicine (Baltimore), 2023, 102(44):e34780. doi:10.1097/MD.0000000000034780.
[18]	Ren C, Ren H, Ren X, et al. Case report:autoimmune encephalitis associated with anti-glutamic acid decarboxylase antibodies:a pediatric case series[J]. Front Neurol, 2021, 12:641024. doi:10.3389/fneur.2021.641024.
[19]	Mitra A, Srivastava N K, Vivek A, et al. Anti-N-methyl-D-aspartate receptor encephalitis preceding stroke: report of an unusual case with literature review[J]. Encephalitis, 2025, 5(3):71-76. doi:10.47936/encephalitis.2025.00017.
[20]	张瀚文, 李强, 杨雪莲, 等. 不同溶栓方案治疗不同特征超早期急性脑梗死的效果分析[J]. 天津医药, 2025, 53(7):770-775.
	Zhang H W, Li Q, Yang X L, et al. Curative effect of different thrombolytic regimens on patients with ultra-early acute cerebral infarction of different characteristics[J]. Tianjin Med J, 2025, 53(7):770-775. doi:10.11958/20250926.
[21]	Ariño H, Höftberger R, Gresa-Arribas N, et al. Paraneoplastic neurological syndromes and glutamic acid decarboxylase antibodies[J]. JAMA Neurol, 2015, 72(8):874-881. doi:10.1001/jamaneurol.2015.0749.
[22]	谷逸欣. 6例抗谷氨酸脱羧酶65抗体脑炎临床分析并文献复习[D]. 银川: 宁夏医科大学, 2025.
	Gu Y X. Clinical analysis of 6 cases of anti-glutamic acid decarboxylase 65 antibody encephalitis and literature review[D]. Yinchuan: Ningxia Medical University, 2025. doi:10.27258/d.cnki.gnxyc.2025.000164.
[23]	Fan X, Li X, Wang S, et al. Clinical heterogeneity in acute symptomatic seizures due to autoimmune encephalitis related to GAD65 antibodies[J]. Neuroimmunomodulation, 2022, 29(3):171-176. doi:10.1159/000519229.
[24]	Sun Y, Sun R, Lv J, et al. Diagnosis and subtyping of autoimmune encephalitis using an attention-based multi-instance learning model:a multi-center 18F-FDG PET study[J]. CNS Neurosci Ther, 2025, 31(8):e70513. doi:10.1111/cns.70513.
[25]	Sun Y, Li G, Liu X, et al. Cerebral glucose hypometabolism and hypoperfusion of cingulate gyrus:an imaging biomarker of autoimmune encephalitis with psychiatric symptoms[J]. J Neurol, 2024, 271(3):1247-1255. doi:10.1007/s00415-023-12051-z.
[26]	Dalakas M C. Stiff-person syndrome and GAD antibody spectrum disorders:GABAergic neuronal excitability,immunopathogenesis and update on antibody therapies[J]. Neurotherapeutics, 2022, 19(3):832-847. doi:10.1007/s13311-022-01188-w.
[27]	Teng Y, Li T, Yang Z, et al. Clinical features and therapeutic effects of anti-leucine-rich glioma inactivated 1 encephalitis:a systematic review[J]. Front Neurol, 2022, 12:791014. doi:10.3389/fneur.2021.791014.
[28]	Gillon S, Chan M, Chen J, et al. MR imaging findings in a large population of autoimmune encephalitis[J]. AJNR Am J Neuroradiol, 2023, 44(7):799-806. doi:10.3174/ajnr.A7907.
[29]	Abunada M, Nierobisch N, Ludovichetti R, et al. Autoimmune encephalitis:early and late findings on serial MR imaging and correlation to treatment timepoints[J]. Eur J Radiol Open, 2024, 12:100552. doi:10.1016/j.ejro.2024.100552.
[30]	Tan Y, Liu M, He L. Clinical and MRI differential analysis of autoimmune encephalitis and viral encephalitis[J]. J Taibah Univ Med Sci, 2022, 18(2):271-278. doi:10.1016/j.jtumed.2022.09.016.
[31]	Zhang Y, Huang H J, Chen W B, et al. Clinical efficacy of plasma exchange in patients with autoimmune encephalitis[J]. Ann Clin Transl Neurol, 2021, 8(4):763-773. doi:10.1002/acn3.51313.