Neuropsychiatric Features of Neurosyphilis: Frequency, Relationship with the Severity of Cognitive Impairment and Comparison with Alzheimer Disease

Abstract

Background: The pattern of neuropsychiatric features of patients with neurosyphilis and the impact of the severity of cognitive impairment on neuropsychiatric syndromes are unknown. Objective: We aim to assess the neuropsychiatric features of patients with neurosyphilis, and compare the impact of the severity of cognitive impairment on the neuropsychiatric syndromes between neurosyphilis and Alzheimer disease (AD). Methods: Neuropsychiatric symptoms and the degree of cognitive impairment were assessed in a case-control study of 91 neurosyphilis, 162 AD, 157 mild cognitive impairment, and 139 normal controls by the Neuropsychiatric Inventory (NPI) scale and Clinical Dementia Rating scale, respectively. Factor analysis was performed on the 12 NPI items. Results: Factor analysis showed that patients with neurosyphilis showed more severe neuropsychiatric syndromes at the dementia stage than those neurosyphilis patients at the mild cognitive impairment stage, while neuropsychiatric manifestations were equally common among the different stages of dementia (all p < 0.05). Frontal lobe syndrome was more severe in patients with neurosyphilis than in patients with AD from the early mild cognitive impairment stage to the moderate dementia stage (all p < 0.01). Conclusions: Patients with neurosyphilis show different patterns of neuropsychiatric syndromes at the mild cognitive impairment and dementia stages, and differ from patients with AD.