Selective impairment of attention function in human immunodeficiency virus-negative patients with early forms of neurosyphilis

Background: Cognitive impairment is common in patients with late neurosyphilis (NS). However, the relationship between early forms of human immunodeficiency virus (HIV)-negative NS and cognitive decline remains poorly understood. Hence, this study aimed to explore the characteristics of attention functions (the main cognitive aspect) in HIV-negative patients with early forms of NS and their association with brain magnetic resonance imaging (MRI) abnormalities. Methods In this study, 31 HIV-negative patients without NS, 30 HIV-negative patients with early forms of NS, and 35 healthy controls were enrolled from September 2020 to November 2022. The attentional network test was used to evaluate the performance of three components of attention, namely, alerting, orienting, and executive control. Results Patients with early forms of NS showed poorer performance in orienting and alerting functions than those without NS (F = 6.952, P = 0.011 and F = 8.794, P = 0.004, respectively); however, no difference was observed in executive function between the two groups (F = 0.001, P = 0.980). Multivariate analysis of variance using the Bonferroni post-hoc test indicated that patients with NS exhibited less efficient orienting function (P = 0.023), alerting function (P = 0.003) but not executive function (P = 1.0) than those without NS. Moreover, compared with contemporary healthy controls, a significant difference in orienting function was observed in patients with NS (P < 0.001). The NS group comprised more patients with MRI abnormalities in the frontal lobes and/or the temporoparietal junction than the non-NS group (24/25 vs. 13/19, P = 0.032). Conclusions HIV-negative patients with early forms of NS demonstrated obvious orientation and alerting function impairment. Brain MRI abnormalities in the frontal and/or parietal lobes and/or the temporoparietal junction indicated the presence of potential neural structure and network priority barriers pertaining to selective attention deficit.