Clinical and Biological Characteristics of 40 Patients with Neurosyphilis and Evaluation of Treponema pallidum Nested Polymerase Chain Reaction in Cerebrospinal Fluid Samples

Abstract

Background. Syphilis remains a significant public health problem. We conducted a prospective study to define more precisely the clinical and biological characteristics of patients with neurosyphilis (NS), and we assessed the diagnostic value of nested polymerase chain reaction (PCR) testing for Treponema pallidum in cerebrospinal fluid (CSF) samples. Methods. From 2001 to 2013, we included 40 patients (90% men; 45% infected with human immunodeficiency virus) with NS, defined as syphilis with neurological and/or ophthalmological symptoms and CSF abnormalities. Results. Thirty patients (75%) had early, 5 (12.5%) had late, and 5 had meningovascular NS. Twenty-four patients (80%) with early NS had ophthalmological symptoms, 14 (47%) had neurological symptoms, and 8 (26%) had both. All patients with meningovascular NS had only neurological symptoms. All patients with late NS had neurological symptoms, and 2 (40%) also had ocular symptoms. Ophthalmological symptoms were present in 65% of all patients with NS, and neurological symptoms in 60%. Seventeen patients (42.5%) had CSF white blood cell counts >20/μL (mean, 57/μL), and 27 (67.5%) had high CSF protein levels (>0.5 g/L; mean value, 1 g/L). CSF PCR results were positive in 42%, and CSF VDRL results in 30%. The nested PCR assay had an overall sensitivity of 42.5%, a specificity of 97%, a positive predictive value of 77%, and a negative predictive value of 86%. Conclusions. Early NS is the most frequent presentation, with an overrepresentation of polymorphous ophthalmological symptoms. PCR is highly specific and of potential value when used with other biological parameters.