Comparison of Clinical and Laboratory Characteristics of General Paresis and Non-Neurosyphilis Dementia

The differential diagnosis of general paresis (GP) and non-neurosyphilis (NS) dementia is not clearly defined. The present study examined the differences in clinical and laboratory features of GP and non-NS dementia.

We retrospectively examined clinical and laboratory features of 85 GP patients and 196 non-NS dementia patients. Data were collected from Zhongshan Hospital between June 2005 and June 2014.

The GP group had a higher percentage of males (83.53%, 71/85) and younger median age ([52 [interquartile range 47.0-61.0] vs. 76 [68.3-82.0] years) than the non-NS dementia group. GP have higher Mini-Mental State Examination (MMSE; Z = -5.809; p = 0.000) than non-NS dementia. Distribution of CDR scores were significantly higher in the non-NS group than GP group (χ2 = 29.153; p = 0.000). The laboratory findings showed significantly different total cholesterol (CH), low-density lipoprotein CH and homocysteine levels between the 2 groups. Serologic testing for syphilis revealed that the GP group had higher seropositive rapid plasma reagin (RPR) and Treponema pallidum particle agglutination (TPPA) rates than the non-NS dementia group (96.47% [82/85] vs. 0.51% [1/196], Z = -2.663, p = 0.008; 100% [85/85] vs. 1.02% [2/196], Z = -2.663, p = 0.008). Interestingly, cerebrospinal fluid (CSF) biochemical indices, including pleocytosis rates, increased protein levels, and positive RPR and TPPA rates in the GP group were higher than that in the non-NS dementia group.

Based on these preliminary data, patients with clinically evident symptoms of dementia, especially middle-aged males, should undergo blood tests for syphilis. All patients with positive serology results should undergo CSF examinations to diagnose GP dementia before further pharmaceutical and behavioral interventions.