Neurosyphilis Treatment Outcomes After Intravenous Penicillin G Versus Intramuscular Procaine Penicillin Plus Oral Probenecid

Insights Into Treatment Alternatives for Neurosyphilis: Systematic Literature Review and Meta-Analysis

ABSTRACT

We conducted a systematic literature review and meta-analysis to assess the efficacy of alternative treatments for neurosyphilis. We searched MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Embase, Cochrane, Scopus, and Web of Science from database inception to September 2023, for studies in neurosyphilis that compared penicillin monotherapy with other treatments. We focused on the impact of these therapies on treatment response, but also assessed data regarding reinfection and adverse drug events. Random-effect models were used to obtain pooled mean differences. Of 3415 screened studies, 6 met the inclusion criteria for the systematic literature review. Three studies provided quantitative data that allowed for inclusion in the meta-analysis. Our analysis revealed that the efficacy of intravenous (IV) ceftriaxone 2 g daily for 10 days (51 patients) did not appear statistically different compared with IV penicillin G 18 to 24 million units daily for 10 days (185 patients) for neurosyphilis (pooled odds ratio, 2.85; 95% confidence interval, 0.41-19.56; I 2 = 49%). No statistical difference between ceftriaxone and penicillin was identified in people living with human immunodeficiency virus (HIV) (pooled odds ratio, 4.51; 95% confidence interval, 0.50-40.49; I 2 = 34%). We concluded that alternative therapy with IV ceftriaxone appears similar to penicillin, potentially expanding treatment options for neurosyphilis. Other treatment options including doxycycline warrant further study.

Clinical Insights: Antimicrobial Therapy for Infectious Uveitis

Infectious uveitis is a major global cause of vision impairment. Despite the eye's immune privilege, afforded by the blood-ocular barrier that restricts microbial entry, several pathogens such as bacteria, viruses, fungi, and parasites can still infiltrate and cause ocular infections and complications. Clinicians often encounter significant challenges in treating infectious uveitis due to limited or ineffective treatment options. Modern molecular techniques and imaging can aid in diagnosing and assessing intraocular infections. Various antimicrobial therapies exist, spanning topical and systemic treatments, but these are constrained by issues like drug concentration, penetration, effective duration, toxicity, and side effects. Treatment approaches also differ based on the infection's etiology. This review provides recent updates on antimicrobial therapies from a clinical perspective, covering topical, systemic, and regional treatments for infectious uveitis.

A rare case report of bilateral vestibulopathy due to otosyphilis

RATIONALE

Bilateral vestibulopathy is an important cause of imbalance. There are multiple etiologies of bilateral vestibulopathy (BVP), but reports of BVP due to otosyphilis are rare.

PATIENT CONCERNS

A 39-year-old male was referred to our medical center due to vertigo, persistent dizziness and gait disturbance for 2 months.

DIAGNOSES

Bilateral vestibulopathy due to otosyphilis was considered in this case, as confirmed through analyses of vestibular function, laboratory tests, and penicillin treatment.

INTERVENTIONS

The patient was was treated with a high dose of penicillin G (24 × 106 IU/d) for 14 days.

OUTCOMES

The patient's symptoms had improved greatly following treatment, with dizziness and gait disturbance having completely resolved at 3 months following hospital discharge.

LESSONS

Bilateral vestibulopathy should be considered when evaluating patients with acute or subacute persistent dizziness. Clinicians should also be aware of the potential for otosyphilis among patients who report BVP.

State-of-the-Art Review: Neurosyphilis

We review key concepts in the diagnosis, treatment, and follow-up of individuals with neurosyphilis. We describe the epidemiology of syphilis in the United States, highlight populations that are markedly affected by this infection, and attempt to estimate the burden of neurosyphilis. We describe the cardinal clinical features of early and late (tertiary) neurosyphilis and characterize the clinical significance of asymptomatic neurosyphilis in the antibiotic era. We review the indications for cerebrospinal fluid (CSF) examination and the performance characteristics of different CSF assays including treponemal and lipoidal antibodies, white cell count, and protein concentration. Future biomarkers and the role of imaging are briefly considered. We review preferred and alternative treatments for neurosyphilis and evidence for their use, including evidence for the use of enhanced intramuscular benzathine penicillin G to supplement intravenous penicillin.

Cerebrospinal Fluid Biomarkers of Symptomatic Neurosyphilis in People With HIV Compared with Uninfected Individuals

We evaluated the diagnostic clinical performance characteristics (DCPC) of cerebrospinal fluid (CSF) total protein (TP), white blood cell count (WBC), and lactate (LA) with different cutoff points as adjunct biomarkers of confirmed or presumptive symptomatic neurosyphilis (NS) and the impact of HIV infection. From 5,640 participants who underwent lumbar punctures, 236 participants were included, and classified as either people with HIV (PWH) or people without HIV (PWoH) according to the CDC criteria for confirmed NS (n = 42), presumptive NS (n = 74), systemic syphilis (SS) (n = 38), serological diagnosis of syphilis (n = 18), PWH without SS and NS (n = 10), and negative control (n = 72). In PWoH, for presumptive NS, the combination of CSF TP > 45 mg/dL and/or WBC > 5.0 cells/mm3 is valuable for screening, whereas in PWH, it is not recommended for either screening or case-finding NS, however the DCPC were better in the suppressed group. In PWoH, the value of CSF TP > 45 mg/dL is adequate for both screening and confirmation of presumptive NS, subject to prevalence. For WBC count > 20 cell/mm3, the positive predictive value (PPV) of the test is almost perfect, suggesting a confirmatory test. In PWH, CSF TP is an inadequate marker of NS. The WBC count, with cutoffs of > 10 or > 20 cells/mm3, was moderately applicable for screening.As conclusions: CSF WBC count and TP showed distinct DCPC in confirmed or presumptive NS, better in the former. These biomarkers could be included for presumptive NS diagnosis. DCPC of these biomarkers for the diagnosis of NS is greatly affected by HIV co-infection.

Serum Neurofilament Light in Neurosyphilis: A Pilot Study

Background:

Lumbar puncture is recommended for individuals with syphilis who have neurological symptoms, however symptoms have poor sensitivity for predicting symptomatic neurosyphilis. Neurofilament light chain (NfL) is a marker for neuroaxonal injury; cerebrospinal fluid concentrations are higher in symptomatic neurosyphilis than in uncomplicated syphilis or asymptomatic neurosyphilis.

Methods:

Serum NfL was quantified in 20 individuals with uncomplicated syphilis, 10 with asymptomatic neurosyphilis and 10 with symptomatic neurosyphilis using an ultrasensitive single molecule array assay; it was repeated a median of 12.5 months after neurosyphilis therapy. Serum NfL concentration was age-adjusted using a published formula.

Results:

Age-adjusted serum NfL concentration was significantly higher in symptomatic neurosyphilis compared to each of the other two groups. It was above the highest value in uncomplicated syphilis in one of 10 participants with asymptomatic neurosyphilis and 3 of 10 with symptomatic neurosyphilis. Serum NfL concentration increased in one participant with asymptomatic neurosyphilis with possible treatment failure.

Conclusions:

If confirmed in a larger study, serum NfL may be a useful adjunct for identifying central nervous system infection by T. pallidum .

Age-adjusted serum neurofilament light (NfL) concentration was elevated in one of 10 individuals with asymptomatic neurosyphilis, and in three of 10 with symptomatic neurosyphilis, suggesting neuroaxonal injury in these persons.

Advances in laboratory diagnostic methods for cerebrospinal fluid testing for neurosyphilis

Neurosyphilis is a chronic infectious disease caused by the invasion of Treponema pallidum into the central nervous system. In recent years, with the increase in the latent syphilis infection rate, the incidence of neurosyphilis has gradually increased, the typical symptoms of neurosyphilis have decreased, atypical manifestations have increased, and the clinical manifestations have become increasingly diverse. Cerebrospinal fluid testing plays an important role in the diagnosis of neurosyphilis. In recent years, there have been many advances in cerebrospinal fluid testing. This review focuses on the current and potential laboratory indicators of neurosyphilis in cerebrospinal fluid, aiming to provide a reference for clinical application and ideas for future experimental research of neurosyphilis.

An Updated Review of Recent Advances in Neurosyphilis

Neurosyphilis is caused by Treponema pallidum invading the central nervous system, of which the incidence is increasing worldwide. Due to its variable clinical manifestations, diagnosis of neurosyphilis remains challenging, especially the asymptomatic form. This review focuses on recent advances in neurosyphilis, including epidemiology, clinical manifestations, laboratory findings, comorbidities, diagnosis, treatment, prognosis, and basic research. The expansion of men who have sex with men and the infection of human immunodeficiency virus mainly accounted for the increasing incidence of neurosyphilis. The rate of some historically described forms of neurosyphilis in the pre-antibiotic era declined significantly; atypical features are more prevalent. Neurosyphilis, regarded as a great mimicker for neuro-ophthalmic, audio-vestibular, and psychiatric disorders, often presents concomitantly with other diseases, including metabolic disorders. Studies on long non-coding RNAs, miRNAs, chemokines, and metabolites in peripheral blood and cerebrospinal fluid may facilitate exploring the pathogenesis and identifying novel biomarkers of neurosyphilis. The drug resistance of Treponema pallidum to penicillin has not been reported; ceftriaxone was proposed to be more effective than penicillin, whereas few randomized controlled trials supported this view. This study may pave the way for further research, especially the diagnosis and treatment of neurosyphilis.

Clinical features and incidence of visual improvement following systemic antibiotic treatment in patients with syphilitic uveitis

To describe the clinical features, longitudinal pattern, and incidence rate of improvement of visual acuity (VA) following antibiotic therapy in patients with syphilitic uveitis. A total of 36 patients were included in this retrospective study from 2009 to 2020. The longitudinal patterns of mean VA values during follow-up were analyzed using a linear mixed model. Most patients were men with HIV coinfection (81%) and presented with panuveitis (49%). The mean VA at baseline improved from 0.97 to 0.39 logMAR at 6 months and remained stable thereafter. The cumulative incidence of VA ≥ 20/25 achieved by 2 years was 70%. Receiving antibiotic therapy within four weeks of the onset of ocular symptoms (adjusted hazard ratio [aHR] 3.4, P = 0.012), absence of HIV coinfection (aHR 8.2, P < 0.001), absence of neurosyphilis (aHR 6.5, P = 0.037), better presenting VA (aHR 5.0, P = 0.003), and intermediate uveitis as opposed to panuveitis (aHR 11.5, P = 0.013) were predictive of achieving VA ≥ 20/25. Men with HIV coinfection represented the majority of our patients. Visual outcomes, in response to antibiotics, were favorable. Delayed treatment, poor presenting VA, presence of HIV coinfection, and concomitant neurosyphilis decreased the likelihood of VA restoration.

Treatment Challenges in a Severe Case of Syphilitic Myelitis With a Longitudinally Extensive Spinal Cord Lesion

Syphilitic myelitis is an unusual manifestation of neurosyphilis, rarely reported in the literature. The best management approach remains unclear in severe cases with longitudinally extensive spinal cord lesions. We describe a 29-year-old man with a history of incompletely treated syphilis after a high-risk sexual encounter, who presented two years later with several weeks of progressive numbness and weakness in both legs. MRI spine showed significant cord expansion from the craniocervical junction to T6 with patchy cord enhancement. He was diagnosed with syphilitic myelitis given his history of inadequately treated syphilis, positive serum rapid plasma reagin at a high titer, and CSF pleocytosis with elevated protein along with a reactive CSF Venereal Disease Research Laboratory test. Alternative infectious or immunological etiologies were excluded. He was treated with IV penicillin and pulse steroid therapy with IV methylprednisolone 1 g daily for 3 days with improvement. However, he was soon readmitted with recurrent weakness requiring an additional course of pulse steroid therapy followed by a short prednisone taper. Afterward, his symptoms recurred with worsened cord expansion on imaging. He was re-treated with IV penicillin and pulse steroid therapy with a more prolonged prednisone taper. The patient subsequently improved and had no further recurrent symptoms on extended outpatient follow-up. This report illustrates the importance of keeping syphilitic myelitis on the differential as a treatable cause of longitudinally extensive myelopathy. The patient may have benefited from high-dose IV steroids with a prolonged taper while waiting for the full treatment effect of antibiotics.

Syphilitic Outer Retinopathy: A Case Report and Review of the Literature

Purpose:

This work presents a case of syphilitic outer retinopathy with findings similar to those of acute zonal occult outer retinopathy (AZOOR). We also discuss the clinical characteristics, treatment, and prognosis of this entity.

Methods:

A case report and systematic literature review are presented.

Results:

A 56-year-old woman presented with acute vision loss, localized photopsia, a central scotoma, and retinal findings that were all consistent with AZOOR. A further workup led to a diagnosis of syphilis. Oral prednisone and intravenous penicillin resulted in the resolution of the posterior uveitis and the restoration of visual acuity. However, the central scotoma remained at the 3-year follow-up visit.

Conclusions:

Syphilitic outer retinopathy is a distinct entity characterized by the disruption of the ellipsoid zone visible on optical coherence tomography and a corresponding increase in fundus hyperautofluorescence in the affected areas. Although some patients may present with a demarcation line, as is seen with AZOOR, the fundus is oftentimes unremarkable or may show only subtle retinal pigment epithelium changes. Uveitis resolution and visual acuity restoration may be expected following treatment; however, visual field disturbances may persist.

Existing Data Sources for Clinical Epidemiology: The Danish Study Group of Infections of the Brain Database (DASGIB)

Central nervous system (CNS) infections are rare diseases that are associated with considerable morbidity and mortality. Increased knowledge based on contemporary data is a prerequisite for improved management and prevention of these serious conditions. Yet, population-based databases of patients hospitalized with CNS infections remain scarce. The Danish Study Group of Infections of the Brain (DASGIB) has prospectively registered information on all adults ≥18 years of age admitted with CNS infections at departments of infectious diseases in Denmark since 2015. The main variables collected are baseline demographics, blood and cerebrospinal fluid tests, imaging results, and outcome using the Glasgow Outcome Scale score. To investigate important aspects for each type of CNS infections, additional variables are included specifically for bacterial meningitis, viral meningitis, encephalitis, brain abscess, neurosyphilis, and Lyme neuroborreliosis. From 2015 to 2020, a total of 3579 cases of CNS infections have been recorded in the DASGIB database. Using the unique civil registration number assigned to all Danish residents, the database can be unambiguously linked with nationwide healthcare registries at the individual level. This enables researchers to conduct detailed population-based and longitudinal observational studies of risk and prognosis of CNS infections and to compare them with matched population cohorts. The database is well-suited for epidemiological research and the DASGIB network forms a solid infrastructure for future national and international collaborations.

The Intersection of HIV and Syphilis: Update on the Key Considerations in Testing and Management

PURPOSE OF REVIEW

To highlight recent trends in the epidemiology of HIV and syphilis, the impact of the COVID epidemic, our approach to care of co-infected patients, and our views on important next steps in advancing the field.

RECENT FINDINGS

HIV and syphilis co-infection has been on the rise in recent years although since the COVID pandemic there is a decrease in new diagnoses-it remains unclear if this represents a true decline or inadequate testing or under-reporting. Standard HIV care should include regular syphilis serology .Treatment and serological follow-up of syphilis in HIV positive and negative patients can be conducted similarly. Challenges remain in the diagnosis and management of neurosyphilis. New models for testing and prevention will be crucial next steps in controlling co-infection. The intersection of HIV and syphilis infections continues to pose new and unique challenges in diagnosis, treatment, and prevention.

cRGDyK-modified procaine liposome inhibits the proliferation and motility of glioma cells via the ERK/p38MAPK pathway

Glioma is a common type of primary tumor in the central nervous system. Glioma has been increasing in incidence yearly and is a serious threat to human life and health. The aim of the present study was to prepare liposomes for enhanced penetration of the blood-brain barrier and targeting of glioma. A procaine-loaded liposome modified with the cyclic pentapeptide cRGDyK (Pro/cRGDyK-L) was designed and developed. The particle size, ζ potential, encapsulation efficiency, release profile, stability and hemolysis of Pro/cRGDyK-L were characterized in vitro. The targeting and antitumor effects of Pro/cRGDyK-L were also investigated in vitro and in vivo. The results suggested that the cRGDyK peptide significantly facilitated the ability of liposomes to transfer procaine across the BBB and improved the cellular uptake of procaine by C6 glioma cells. The results further demonstrated that Pro/cRGDyK-L strongly suppressed cell motility, stimulated apoptosis and induced cell cycle arrest. The findings further confirmed that Pro/cRGDyK-L exhibited superior antitumor effects by targeting the ERK/p38MAPK pathway and thereby suppressed tumor growth in mice. In conclusion, the present study indicated the potential of Pro/cRGDyK-L as a means to provide improved therapeutic effects on glioma through the ERK/p38MAPK pathway.

Neurosyphilis and Lyme neuroborreliosis

PURPOSE OF REVIEW

Neurosyphilis (NS) and Lyme neuroborreliosis (LNB) are spirochetal diseases with distinct clinical manifestations. The diagnosis of NS remains challenging due to imperfect diagnostic criteria and testing modalities. With LNB, misconceptions about diagnosis and treatment lead to considerable morbidity and drug related adverse effects.

RECENT FINDINGS

Although studies continue investigating alternate approaches and new diagnostic tests for NS, few data exist to change current approaches to diagnosis, management or follow up. In the diagnosis of LNB, the chemokine CXCL13 shows promising diagnostic accuracy. A systematic review discourages the use of cell-based assays when investigating Lyme disease. Clinical studies show no benefit from extended antibiotic treatment for patients with unspecific symptoms labelled as having Lyme disease.

SUMMARY

The diagnosis of NS may be delayed due to a lack of specificity of findings, low suspicion for syphilis, and/or similarities in presentation to other diseases. A high index of suspicion for syphilis is required provide timely diagnosis and management of NS. Fortunately, penicillin remains the treatment of choice. Overdiagnosis and overtreatment in patients labelled as having Lyme disease can be avoided by an evidence-based approach towards diagnosis and treatment.