Objectives Neurosyphilis has been found to be associated with cognitive decline. However, as a common type of neurosyphilis, the change of cognitive function in asymptomatic neurosyphilis (ANS) has received little attention. This study aims to investigate the cognitive function and cellular metabolism changes in bilateral hippocampus in ANS. Methods Twenty-four ANS, 20 syphilis patients and 23 control individuals who were admitted in Hangzhou Third people’s Hospital from June 2021 to July 2025 were selected. 1 H-MRS (magnetic resonance spectroscopy) was used to detect the cellular metabolism of bilateral hippocampus in these subjects (ANS patients detect before treatment and 6 months posttreatment). The Montreal cognitive assessment (MoCA) was also used to evaluate cognitive function of these patients. Compare the differences between three groups, and changes in ANS patients before and 6 months posttreatment. The correlation between MoCA scores and cellular metabolism of hippocampus were analyzed. Results There was no significant difference in MoCA scores among the three groups ( p 0.05). The NAA/Cr ratios in the bilateral hippocampus of ANS patients was significantly lower than those of the syphilis patients and control group ( p 0.05). The NAA/Cr ratios in the bilateral hippocampus was positively correlated with the MoCA scores ( r = 0.4614, p = 0.0232; r = 0.4133, p = 0.0447); it was negatively correlated with the number of white blood cells and protein levels in cerebrospinal fluid (CSF) ( p 0.05). There was no significant difference in the cellular metabolism of hippocampus between the syphilis and control group (all p 0.05). Compared with before treatment, ANS patients showed a significant improvement in NAA/Cr ratios at 6-month follow-up after high-dose penicillin treatment ( p 0.05), and no difference compared with the syphilis and control groups ( p 0.05). Conclusion 1 H-MRS can effectively detect cellular metabolism changes in hippocampus of ANS patients. Although ANS patients have no obvious clinical symptoms, there are cellular metabolic changes in hippocampus and reduced neuronal metabolic function. Standardized treatment can correct this abnormal change.
Han et al. (Wed,) studied this question.