Neurosyphilis complicated by anti-γ-aminobutyric acid-B receptor encephalitis: A case report

Ya-Xiu Fang; Xiao-Ming Zhou; Dong Zheng; Guang-Hui Liu; Peng-Bo Gao; Xiao-Zhen Huang; Zhi-Cheng Chen; Hui Zhang; Lin Chen; Ya-Fang Hu

doi:10.12998/wjcc.v12.i11.1960

Neurosyphilis complicated by anti-γ-aminobutyric acid-B receptor encephalitis: A case report

World J Clin Cases. 2024 Apr 16;12(11):1960-1966. doi: 10.12998/wjcc.v12.i11.1960.

Authors

Affiliations

¹ Department of Neurology, The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou 510000, Guangdong Province, China.
² Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou 510000, Guangdong Province, China.
³ Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou 510000, Guangdong Province, China. yafanghu@smu.edu.cn.

Abstract

Background: Syphilis is an infectious disease caused by Treponema pallidum that can invade the central nervous system, causing encephalitis. Few cases of anti-N-methyl-D-aspartate receptor autoimmune encephalitis (AE) secondary to neurosyphilis have been reported. We report a neurosyphilis patient with anti-γ-aminobutyric acid-B receptor (GABA_BR) AE.

Case summary: A young man in his 30s who presented with acute epileptic status was admitted to a local hospital. He was diagnosed with neurosyphilis, according to serum and cerebrospinal fluid (CSF) tests for syphilis. After 14 d of antiepileptic treatment and anti-Treponema pallidum therapy with penicillin, epilepsy was controlled but serious cognitive impairment, behavioral, and serious psychiatric symptoms were observed. He was then transferred to our hospital. The Mini-Mental State Examination (MMSE) crude test results showed only 2 points. Cranial magnetic resonance imaging revealed significant cerebral atrophy and multiple fluid-attenuated inversion recovery high signals in the white matter surrounding both lateral ventricles, left amygdala and bilateral thalami. Anti-GABA_BR antibodies were discovered in CSF (1:3.2) and serum (1:100). The patient was diagnosed with neurosyphilis complicated by anti-GABA_BR AE, and received methylprednisolone and penicillin. Following treatment, his mental symptoms were alleviated. Cognitive impairment was significantly improved, with a MMSE of 8 points. Serum anti-GABA_BR antibody titer decreased to 1:32. The patient received methylprednisolone and penicillin after discharge. Three months later, the patient's condition was stable, but the serum anti-GABA_BR antibody titer was 1:100.

Conclusion: This patient with neurosyphilis combined with anti-GABA_BR encephalitis benefited from immunotherapy.

Keywords: Anti-γ-aminobutyric acid-B receptor; Case report; GABABR; Magnetic resonance imaging; Mini-mental state examination; Neurosyphilis; Tissue-based assay.

Publication types

Case Reports