Alzheimer's Disease and Neurosyphilis: Meaningful Commonalities and Differences of Clinical Phenotype and Pathophysiological Biomarkers

Enhancing clinical awareness: retrospective analysis of neurosyphilis cases and diagnostic predictors for early recognition and treatment

OBJECTIVE

This is a retrospective analysis of clinical data from individuals diagnosed with neurosyphilis, aiming to enhance healthcare professionals' understanding of the disease and expedite early diagnosis and intervention.

METHODS

A retrospective analysis was conducted on the clinical records of 50 patients who received a diagnosis of symptomatic neurosyphilis and were admitted to the Neurology Department during the period spanning January 2012 to December 2022.

RESULTS

Clinical manifestations encompassed diverse phenotypes, with syphilitic meningitis accounting for 16% of cases, characterized by symptoms such as headache, blepharoptosis, paralysis, blurred vision, and tinnitus. Meningovascular syphilis presented in 36% of cases, exhibiting episodic loss of consciousness, limb numbness, and limb convulsion. Paralytic dementia manifested in 36% of cases, featuring symptoms such as memory loss, sluggish response, and slow movement. Tabes dorsalis was observed in 12% of cases, presenting with weakness, numbness, and staggering. Routine cerebrospinal fluid (CSF) analysis indicated abnormal white blood cell counts in 60% of patients, while biochemical testing revealed abnormal protein content in 52% of patients. Notably, statistically significant differences were observed between patients with interstitial and parenchymatous neurosyphilis (Z = 2.023, P = 0.044) in terms of CSF protein content. Electroencephalogram (EEG) results were abnormal in six patients, and imaging studies unveiled diverse findings in 46 patients.

CONCLUSION

The study highlights the importance of neurological and/or ocular symptoms in diagnosing symptomatic neurosyphilis. Individuals with hypomnesia should be closely monitored for potential neurosyphilis. Integrating clinical manifestations, laboratory tests, EEG, and imaging can reduce misdiagnosis. This comprehensive approach shows promise in improving early identification and management of neurosyphilis.

Hippocampal region metabolites and cognitive impairment in patients with general paresis: based on 1H-proton magnetic resonance spectroscopy

Background

This study utilizes Hydrogen proton magnetic resonance spectroscopy (1H-MRS) to investigate metabolite concentrations in the bilateral hippocampus of general paresis (GP) patients.

Methods

A total of 80 GP patients and 57 normal controls (NCs) were enrolled. Metabolite ratios in the bilateral hippocampus were measured using 1H-MRS. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Based on MMSE scores, participants were categorized into normal control, mild cognitive impairment, and moderate-severe dementia groups. Metabolite ratios (N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/creatine (Cr), N-acetylaspartate (NAA)/choline (Cho), myoinositol (MI)/creatine (Cr), choline (Cho)/N-acetylaspartate (NAA)) were compared between groups, and correlations between metabolite ratios and cognitive performance were examined.

Results

MMSE scores progressively decreased in the normal, mild cognitive impairment, and moderate-severe dementia groups (p < 0.001). The moderate-severe dementia group showed significantly lower NAA/Cr ratios in the left hippocampus region (L-NAA/Cr ratios) (p < 0.001) and higher Cho/NAA ratios in the left hippocampus region (L-Cho/NAA ratios) (p < 0.05) compared to the other groups. However, differences in L-NAA/Cr and L-Cho/NAA ratios between the mild cognitive impairment group and the NC group were not significant in the hippocampus region (p > 0.05). NAA/Cho and NAA/Cr ratios in the right hippocampus region (R-NAA/Cho and R-NAA/Cr ratios) in the moderate-severe dementia group were lower than those in the control group (p < 0.05). No correlation was found between metabolite ratios and MMSE scores in bilateral hippocampus regions.

Conclusion

There are distinctive metabolic characteristics in the hippocampus of GP patients. GP patients exhibited lower NAA/Cr and NAA/Cho ratios in the bilateral hippocampus, indicating neuron loss in these areas, which may become more pronounced as the disease progresses.

Neutrophil CD64 index as a potential blood biomarker for the diagnosis of neurosyphilis in secondary and tertiary syphilis: A retrospective study

Objective

To examine the correlation of neutrophil CD64 (nCD64) index with neurosyphilis (NS) across different stages of syphilis.

Methods

A total of 1243 syphilis patients at different stages (344 of primary, 385 of secondary, and 514 of tertiary) included in this study were divided into NS and non-NS (NNS). Correlations of nCD64 index with currently used syphilis biomarkers were explored using Spearman correlation test. Relationships between nCD64 index and NS at different stages were investigated by stratified analysis and restricted cubic spline model. The diagnostic performance of nCD64 index for NS was assessed by receiver operating characteristic (ROC) curve.

Results

Significant statistical correlations of nCD64 index with cerebrospinal fluid (CSF) NS indicators were found in secondary and tertiary syphilis. Increased nCD64 index was associated with increased risk of NS in secondary and tertiary syphilis. ROC analysis values further confirmed the diagnostic potential of nCD64 index for NS. Marked decrease of nCD64 index was observed in NS patients after effective antisyphilitic treatments.

Conclusions

The nCD64 index may help to the diagnosis of NS in secondary and tertiary syphilis.