Neurosyphilis presenting as autoimmune limbic encephalitis: A case report and literature review

Clinical and laboratory characteristics of neurosyphilis: analysis of symptoms and risk factors

BACKGROUND

The present study was conducted from 2021 to 2023 to analyze the clinical and laboratory characteristics of neurosyphilis and determine the risk factors associated with this condition.

METHODS

A total of 400 patients were enrolled, including 100 individuals diagnosed with neurosyphilis, 100 without neurosyphilis, 100 with latent syphilis, and 100 healthy control subjects. Comparative analysis methods, serum VDRL titration, and correlation analysis were employed during the study.

RESULTS

The analysis revealed significant differences in symptoms of central nervous system (CNS) involvement and serum VDRL titers among the patient groups. For instance, symptoms indicative of CNS impairment were more frequently observed in patients with neurosyphilis, and serum VDRL titers were statistically significantly higher in this same group.

CONCLUSIONS

The obtained results can be utilized in clinical practice to enhance the accuracy of neurosyphilis diagnosis and management, thereby contributing to the improvement of early detection of this condition and prevention of its complications. The study allows for the inference of the importance of early detection of (CNS) dysfunction symptoms in patients (neurosyphilis) with syphilis and identifies key factors influencing the development of this disease. The findings hold significance for the diagnosis and treatment of neurosyphilis.

Abnormal CSF-Specific OCBs in Neuronal Surface Antibody-Associated Autoimmune Encephalitis Differentiating from Viral Encephalitis

Purpose

The present study aimed to examine the clinical distinctions among patients with neuronal surface antibody-associated autoimmune encephalitis (NSAE) diagnosed with anti-N-methyl-D-aspartate receptor encephalitis (NMDAR-E), anti-leucine-rich glioma-inactivated 1 encephalitis (LGI1-E), and anti-gamma aminobutyric acid-B receptor encephalitis (GABABR-E), compared with those with viral encephalitis (VE). Additionally, the study aimed to assess the impact of cerebrospinal fluid (CSF) oligoclonal bands (OCBs) on the severity and prognosis of NSAE.

Patients and Methods

This retrospective analysis included patients with NSAE, encompassing NMDAR-E, LGI1-E, and GABABR-E, alongside individuals with VE. Participants with NSAE were categorized into two groups based on the presence or absence of CSF-specific OCBs. Data regarding demographics, clinical manifestations, magnetic resonance imaging (MRI) findings, CSF analyses and prognosis were collected and analyzed.

Results

The findings indicated that younger female with NSAE exhibited a higher incidence of seizure onset, disruption of the blood-CSF barrier (BCSFB), and elevated QAlb/QLim ratios compared to VE patients, with NSAE patients demonstrating more severe clinical outcomes at discharge. Among the 185 NSAE patients, 43 (23.24%) were positive for OCBs, while 142 (76.76%) negative. The OCB-positive cohort displayed a greater prevalence of younger females and NMDAR-E (both P<0.05). No significant differences were observed in CSF white blood cell counts, protein concentrations, or immunoglobulin G levels between the two groups (all P>0.05). The modified Rankin Scale (mRS) scores at discharge and the final follow-up were higher in the OCB-positive group than the OCB-negative group (both P<0.05). Both univariate and multivariate analyses identified OCBs and NSAE subtypes as independent risk factors influencing the clinical prognosis of NSAE.

Conclusion

In comparison to VE patients, NSAE patients with positive OCBs were more frequently female and exhibited CSF pleocytosis, particularly among those with NMDAR-E. Importantly, the presence of positive OCBs emerged as an independent predictor of unfavorable outcomes in patients with NMDAR-E, LGI1-E, and GABABR-E.

Neurosyphilis complicated by anti-γ-aminobutyric acid-B receptor encephalitis: A case report

BACKGROUND

Syphilis is an infectious disease caused by Treponema pallidum that can invade the central nervous system, causing encephalitis. Few cases of anti-N-methyl-D-aspartate receptor autoimmune encephalitis (AE) secondary to neurosyphilis have been reported. We report a neurosyphilis patient with anti-γ-aminobutyric acid-B receptor (GABABR) AE.

CASE SUMMARY

A young man in his 30s who presented with acute epileptic status was admitted to a local hospital. He was diagnosed with neurosyphilis, according to serum and cerebrospinal fluid (CSF) tests for syphilis. After 14 d of antiepileptic treatment and anti-Treponema pallidum therapy with penicillin, epilepsy was controlled but serious cognitive impairment, behavioral, and serious psychiatric symptoms were observed. He was then transferred to our hospital. The Mini-Mental State Examination (MMSE) crude test results showed only 2 points. Cranial magnetic resonance imaging revealed significant cerebral atrophy and multiple fluid-attenuated inversion recovery high signals in the white matter surrounding both lateral ventricles, left amygdala and bilateral thalami. Anti-GABABR antibodies were discovered in CSF (1:3.2) and serum (1:100). The patient was diagnosed with neurosyphilis complicated by anti-GABABR AE, and received methylprednisolone and penicillin. Following treatment, his mental symptoms were alleviated. Cognitive impairment was significantly improved, with a MMSE of 8 points. Serum anti-GABABR antibody titer decreased to 1:32. The patient received methylprednisolone and penicillin after discharge. Three months later, the patient's condition was stable, but the serum anti-GABABR antibody titer was 1:100.

CONCLUSION

This patient with neurosyphilis combined with anti-GABABR encephalitis benefited from immunotherapy.

Neurosyphilis presenting as limbic encephalitis

A man in his 50s presented with focal seizures and was found to have an inflammatory cerebrospinal fluid (CSF) with bilateral mesiotemporal lobe hyperintensity on magnetic resonance imaging (MRI) of the brain. Corticosteroid treatment was initiated for management of limbic encephalitis. Focal seizures, imaging abnormalities and inflammatory CSF persisted despite treatment and the patient was found to have neurosyphilis after developing neuropsychiatric symptoms. Syphilis is a sexually transmitted bacterial infection with multisystem involvement including neurological and psychiatric manifestations. Case reports have emerged of neurosyphilis presenting as limbic encephalitis with CSF pleocytosis and temporal lobe hyperintensity on MRI of the brain. Persistence of CSF or MRI abnormalities despite immunosuppressive therapy for limbic encephalitis should prompt investigation for alternate causes of chronic meningoencephalitis, which can occasionally include neurosyphilis.

Neurosyphilis with positive anti-N-methyl-D-aspartate receptor antibody: a case report

A case of neurosyphilis with a positive anti-N-methyl-D-aspartate receptor (NMDAR) antibody was reported. A 54-year-old man who presented with acute memory deficits was admitted to our hospital. Acute ischemic stroke (AIS) was initially considered, and he was prescribed intravenous thrombolysis with recombinant tissue-type plasminogen activator (rt-PA). However, the intermittent onset of episodic memory and orientation disorder still occurred. No diffusion restriction was indicated by magnetic resonance imaging (MRI), and subclinical seizures were frequently found by electroencephalogram (EEG). Rapid plasma reagin (RPR) test of serum showed positive results for syphilis. Analysis of cerebrospinal fluid (CSF) revealed elevated leukocyte count and protein level. RPR test, Treponema pallidum particle agglutination (TPPA) assay, and Treponema pallidum antibody (TP-Ab) in CSF showed positive results, and the anti-NMDAR antibodies were positive in CSF and serum. Finally, the patient was diagnosed with neurosyphilis with a positive anti-NMDAR antibody. The clinical symptoms were improved, and the leukocyte count in CSF was reduced after treatment with intravenous penicillin G and levetiracetam. This case suggests that in cases with positive results for neurosyphilis and NMDAR antibodies, the proper treatment has to be decided based on all of the available clinical and diagnostic testing data.

Neurosyphilis Presenting as Syndrome of Limbic Encephalitis Mimicking Herpes Simplex Virus Neuro-Infection Diagnosed Using CXCL13 Point-of-Care Assay—Case Report

The syndrome of limbic encephalitis is a severe clinical condition with heterogenous aetiopathogenesis. A common pathogen causing the infectious syndrome of limbic encephalitis is herpes simplex virus (HSV), but rare cases caused by Treponema pallidum have also been reported. We present the case of a 46-year-old man who presented with sudden onset of headaches, nausea, vomiting, and short-term loss of consciousness with clonic convulsions and subsequent disorientation and aphasia. Examination of the cerebrospinal fluid (CSF) revealed lymphocytic pleocytosis and magnetic resonance of the brain revealed bilateral temporal lesions. Clinical, radiologic, and biochemical examinations of CSF suggested encephalitis caused by HSV. However, the positivity of CXCL-13 chemokine in the CSF by a rapid point-of-care assay suggested active spirochetal infection and led to further serologic investigation. The definitive diagnosis of neuro-syphilis was concluded by positive intrathecal synthesis of immunoglobulins against Treponema pallidum. Penicillin therapy led to a rapid improvement, and the patient was discharged home after three weeks. Due to memory problems and irritability, after eighteen months, he came for a follow-up neurological and psychological examination. The psychological examination revealed a significant deficit in executive functions and behavioural changes. Neurosyphilis should be considered in the differential diagnosis of limbic encephalitis with lymphocytic pleocytosis in cerebrospinal fluid, and CXCL-13 may help to achieve diagnosis.