Hong-Yan Li,1,2 Hao-Yu Wang,3 Yi-Fei Duan,2,4 Yu Gou,2,4 Xiao-Qin Liu,2,4 Zheng-Xiang Gao2,4 

1West China Second University Hospital, Sichuan University, Chengdu, Sichuan, People’s Republic of China; 2Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, People’s Republic of China; 3Department of Radiology, The First People’s Hospital of Liangshan Yi Autonomous Prefecture, Xichang, Sichuan, People’s Republic of China; 4Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, People’s Republic of China

Correspondence: Zheng-Xiang Gao, Email GAOZX84@163.com

Abstract: Neurosyphilis is a central nervous system infection caused by Treponema pallidum that imitates various neurological and mental disorders. Therefore, patients with this disease are prone to misdiagnoses. Here, we report a case of neurosyphilis with a psychotic disorder as the main manifestation. A young girl exhibited mental and behavioural abnormalities after a heartbreak, which manifested as alternating low mood, emotional irritability, and a lack of interest in social relations, followed by memory loss. The cerebrospinal fluid protein - Treponema pallidum particle agglutination test was positive, the toluidine red unheated serum test titre was 1:4, the white blood cell count was 5 × 10^6/L, the cerebrospinal fluid protein level was 0.97 g/L, and the brain CT was abnormal. After admission, the possibility of neurosyphilis was considered and the patient received intravenous penicillin G treatment. The patient’s clinical symptom ms improved. This case emphasises that doctors should maintain clinical suspicion of Treponema pallidum infection in adolescent patients with mental abnormalities.

Keywords: neurosyphilis, case report, psychotic disorder, Treponema pallidum, syphilis