Abstract

Objective: Neurosyphilis is a severe manifestation of syphilis characterized by heterogeneous clinical presentations. Diagnosis and assessment of treatment response are challenging due to variable findings and limitations in interpreting serological tests. This study evaluates the clinical characteristics, laboratory findings, and treatment outcomes of neurosyphilis cases diagnosed at a single center over an 18-year period.

Methods: Medical records of patients aged 18 years or older with positive syphilis serology who were diagnosed with neurosyphilis between 2005 and 2022 were reviewed in this retrospective observational study. Diagnosis and classification followed Centers for Disease Control and Prevention (CDC) criteria were applied for diagnosis and classification. Demographic data, clinical features, serological and cerebrospinal fluid (CSF) findings, treatments, and post-treatment outcomes were analyzed.

Results: Of 503 patients with positive syphilis serology, 23 (4.6%) were diagnosed with neurosyphilis. Three (13%) patients were female, and 3 (13%) had human immunodeficiency virus infection. All patients were symptomatic; 7 (30.4%) had ocular involvement, and 16 (69.5%) presented with neurological manifestations. Tabes dorsalis was the most common presentation, occurring in seven patients (30.4%). Based on CDC criteria, four cases (17.4%) were classified as possible, 13 (56.5%) as probable, and 6 (26.1%) as confirmed neurosyphilis. Fifteen (65%) patients were in the tertiary stage, and eight (35%) were in the secondary stage. Serum rapid plasma reagin titers ranged from 1:1 to 1:512. The mean CSF leukocyte count was 30/mm3, and CSF protein levels ranged from 24 to 544 mg/dL. CSF Venereal Disease Research Laboratory test results were positive in six patients, and Treponema pallidum hemagglutination assay results were positive in 15 patients. Among 22 patients with follow-up data, seven (32%) achieved full recovery, 14 (64%) developed sequelae, and 1 (4.5%) died during follow-up.

Conclusion: Neurosyphilis exhibits diverse clinical features and remains challenging to diagnose. Patients with syphilis require careful evaluation for neurological and ocular involvement, and syphilis should be included in the differential diagnosis of retinitis and uveitis.