An Updated Review of Recent Advances in Neurosyphilis

Analysis of Neurosyphilis Imaging Methods and Treatment: A Focused Review

Neurosyphilis, a severe complication of syphilis caused by Treponema pallidum, progresses through multiple stages, including asymptomatic, meningeal, meningovascular, and late parenchymal forms such as syphilitic paresis and tabes dorsalis. Neurosyphilis spreads through sexual contact and from mother to child. Symptoms of neurosyphilis include nausea, cranial nerve deficiencies, and seizures. Diagnosing this condition is particularly challenging due to its varied symptoms, which frequently overlap with other neurological disorders. Current diagnostic approaches primarily rely on cerebrospinal fluid (CSF) analysis and neuroimaging techniques like magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT). The exploration of recent advances in neurosyphilis testing and the expanding role of imaging techniques in tracking treatment efficacy are seen. Penicillin G continues to be the primary treatment, with ceftriaxone serving as an alternative for patients with penicillin allergies. Even though ceftriaxone is less potent than penicillin G, it can still successfully eradicate neurosyphilis in patients. This review seeks to deepen the understanding of neurosyphilis pathophysiology, refine diagnostic accuracy, and inform evidence-based treatment approaches. This will ultimately contribute to improved patient outcomes.

Clinical and Laboratory Characteristics, Diagnosis, and Treatment of Patients with Neurosyphilis in Emergency Department: A Retrospective Study of 12 Patients

Purpose

Syphilis, caused by Treponema pallidum, presents a diagnostic challenge due to its diverse clinical manifestations. Neurosyphilis has seen a resurgence in recent years, particularly among men who have sex with men and those living with HIV. Diagnosis of neurosyphilis in emergency settings is challenging due to its varied neurological presentations. This study aims to serve as a reference for dermatologists and neurologists in diagnosing and treating neurosyphilis.

Patients and Methods

This retrospective study analyzed patients who presented with neuropsychiatric symptoms and were ultimately diagnosed with neurosyphilis. These patients were collected from the emergency department in Peking Union Medical College Hospital between January 2018 and November 2023. The medical history, clinical symptoms, laboratory examinations, cranial MRI characteristics, and treatment regimens of these patients were investigated.

Results

Among the included 12 neurosyphilis patients, memory deterioration was observed in 8 out of the 12 neurosyphilis patients. Diagnosis often resulted in delays, with misdiagnoses mainly including Alzheimer's disease, stroke, and epilepsy. Neuroimaging revealed various abnormalities, predominantly affecting ventricular and temporal regions. Treatment with penicillin-based regimens varied in compliance, with only a minority of patients adhering to guidelines. Treatment outcomes were inconsistent, with some patients experiencing irreversible neurological damage and fluctuating serum rapid plasma reagin (RPR) titers.

Conclusion

Diagnosis of neurosyphilis in the emergency department remains challenging, necessitating awareness of its varied neurological presentations. Enhanced diagnostic strategies are imperative to accelerate treatment initiation and improve outcomes for affected individuals.

Infectious Neuropathies

This review explores diverse infectious etiologies of peripheral nervous system (PNS) dysfunction, spanning sensory and motor neurons, nerves, and associated structures. Progress in viral and bacterial infections reveals multifaceted mechanisms underlying neuropathies, including viral neurotoxicity and immune-mediated responses. Latest diagnostic advances facilitate early PNS complication detection, with ongoing research offering promising treatment avenues. Emerging pathogens like severe acute respiratory syndrome coronavirus 2, Zika virus, and EV-D68 highlight the evolving infectious neuropathy paradigm. Recognizing characteristic patterns and integrating clinical factors are pivotal for precise diagnosis and tailored intervention. Challenges persist in assessment and management due to varied pathogenic mechanisms. Advancements in understanding pathogenesis have improved targeted therapies, yet gaps remain in effective treatments. Ongoing research is crucial for optimizing approaches and improving patient outcomes.

Syphilis presenting as optic neuritis and subdural haematoma with complicating neuro Jarisch-Herxheimer reaction

A man in his 50s presented with a 3-week history of painless blurry vision. The ocular examination showed decreased visual acuity and 3+ bilateral papilloedema. A CT of the brain without contrast revealed a 5 mm left subdural haematoma. Anti-treponemal IgG antibodies were positive, and a reflex rapid plasma regain (RPR) was >1:64. HIV serology was negative. Ophthalmology and infectious diseases agreed that the presentation was consistent with ocular syphilis. Cerebrospinal fluid (CSF) examination revealed an elevated CSF protein of 52 mg/dL and CSF Venereal Disease Research Laboratory (VDRL) of 1:1. Penicillin was started. The patient developed a Jarisch-Herxheimer reaction soon after. He had a fever, rash and worsening headaches due to the enlargement of subdural haematoma for which he underwent a burr hole drainage. Vision improved after completing penicillin therapy but did not recover fully. The CSF VDRL became non-reactive and serum RPR titre decreased to 1:8 3 months later.

Landmarks in the history of neurosyphilis: the neglected observations of Vincenzo Chiarugi

After the emergence of syphilis in Europe in 1495, it would take over 400 years to unpick the full course of the infection, including the involvement of the brain and spinal cord. This syndrome of mental and physical deterioration was called 'general paralysis of the insane' (GPI). Traditionally, the earliest clear description of GPI is attributed to Haslam in 1798. However, here I describe three clear cases and three highly suggestive cases, together with autopsy findings, published in 1794 by the Italian psychiatrist Vincenzo Chiarugi. Historically, Chiarugi's scholarship has been neglected in favour of English- and French-speaking physicians. His observations also give a rare clue regarding the prevalence of syphilis, suggesting a foothold in northern Italy in the late eighteenth century.

LC-MS metabolomics and lipidomics in cerebrospinal fluid from viral and bacterial CNS infections: a review

There is compelling evidence that a dysregulated immune inflammatory response in neuroinfectious diseases results in modifications in metabolic processes and altered metabolites, directly or indirectly influencing lipid metabolism within the central nervous system (CNS). The challenges in differential diagnosis and the provision of effective treatment in many neuroinfectious diseases are, in part, due to limited understanding of the pathophysiology underlying the disease. Although there are numerous metabolomics studies, there remains a deficit in neurolipidomics research to provide a comprehensive understanding of the connection between altered metabolites and changes in lipid metabolism. The brain is an inherently high-lipid organ; hence, understanding neurolipidomics is the key to future breakthroughs. This review aims to provide an integrative summary of altered cerebrospinal fluid (CSF) metabolites associated with neurolipid metabolism in bacterial and viral CNS infections, with a particular focus on studies that used liquid chromatography-mass spectrometry (LC-MS). Lipid components (phospholipids) and metabolites (carnitine and tryptophan) appear to be the most significant indicators in both bacterial and viral infections. On the basis of our analysis of the literature, we recommend employing neurolipidomics in conjunction with existing neurometabolomics data as a prospective method to enhance our understanding of the cross link between dysregulated metabolites and lipid metabolism in neuroinfectious diseases.

Diagnosing Tabes Dorsalis in HIV-Negative Patients: Clinical Features, Neuroimaging, and Laboratory Insights in the Modern Antibiotic Era

Background

Tabes dorsalis is a late manifestation of neurosyphilis, characterized by progressive ataxia, lightning pains, loss of proprioception, and urinary incontinence. The absence of a definitive diagnostic standard and the non-specific clinical manifestations have led to a significant rate of misdiagnoses.

Methods

Hospitalized patients with tabes dorsalis at Peking Union Medical College Hospital between January 2010 and December 2023 were reviewed.

Results

A total of 13 patients were included, with 10 males and 3 females. The median age was 50 years (range, 34-64). The most frequent initial symptoms were limb numbness (30.8%) and lightning pains (30.8%). Eleven patients (84.6%) received misdiagnoses prior to the final diagnosis. The most frequently observed physical sign was positive Romberg's sign (84.6%). Notably, Argyll Robertson pupil was presented in 7 subjects (53.8%). Serological tests revealed positive rapid plasma regain (RPR) and Treponema pallidum particle agglutination (TPPA) for all patients. All CSF samples were TPPA-reactive. Intramedullary hyperintensity on T2-weighted imaging of spinal MRI was found in 5 patients (38.5%). All patients received anti-syphilitic treatment, with effective treatment recorded in five cases.

Conclusion

This study underscores the importance of neurological symptoms and signs in diagnosing tabes dorsalis. Individuals with progressive ataxia and positive Romberg's sign should be closely monitored for potential neurosyphilis. Integrating clinical features, laboratory tests, and neuroimaging could reduce misdiagnosis and expedite the initiation of anti-syphilitic therapy.

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.

Psychiatric manifestations of neurosyphilis over past two decades: Findings from a tertiary care neuropsychiatric hospital in south India

OBJECTIVE

To assess presentation of neurosyphilis with a focus on the psychiatric aspects.

METHOD

File review of the cases with a positive cerebrospinal fluid venereal disease research laboratory test between 1999 to 2020.

RESULTS

Medical records of 143 neurosyphilis patients were analysed. Hallucinations, delusions, and catatonia were the commonest psychiatric symptoms. Brain atrophy was the commonest neuroimaging finding. The number of neurosyphilis patients and the proportion with delirium or catatonia declined during the second decade (2010-2020).

CONCLUSION

Atypical presentation of psychiatric symptoms around the fifth decade, with associated neurological symptoms or brain imaging changes, should prompt evaluation for neurosyphilis.

Multicentric evaluation of a specific intrathecal anti-Treponema pallidum IgG index as a diagnostic biomarker of neurosyphilis: results from a retro-prospective case-control study

BACKGROUND AND OBJECTIVES

The diagnosis of neurosyphilis (NS) lacks a true 'gold standard', making the diagnosis challenging while consequences of a misdiagnosis are potentially severe. The aim of this study was to evaluate the diagnostic performance of measuring an antibody index (AI) for the intrathecal synthesis of specific anti-Treponema pallidum (T. pallidum) IgG for the diagnosis of NS.

METHODS

Specific anti-T. pallidum IgG were measured simultaneously in paired cerebrospinal fluid (CSF)-serum samples collected retrospectively and prospectively between 2007 and 2022, from patients suspected of NS, in Switzerland. An AI was calculated to account for blood-brain barrier integrity. Area under the receiver operating characteristic curve, sensitivity/specificity and positive/negative predictive values of AI test were estimated. Two NS definitions were used: NS1 included patients with NS suspicion presenting with neurological symptoms and/or acute neurosensory signs, and positive T. Pallidum Hemagglutinations Assay (TPHA)/T. pallidum particle agglutination assay (TPPA) serology and CSF-TPHA/TPPA ≥320, and either CSF-leucocytes >5 cells/mm3 and/or CSF-protein >0.45 g/L and/or a reactive CSF-venereal disease research laboratory (VDRL)/rapid plasma reagin (RPR) test. NS2 included patients with suspected NS presenting with acute ocular and/or otologic symptoms, and positive TPHA/TPPA serology, and a favourable response to NS treatment. Controls were patients diagnosed with any other central nervous system (CNS) pathologies and with positive TPHA/TPPA serology.

RESULTS

The study included 71 NS (43 NS1 and 28 NS2) and 110 controls. With a threshold of ≥1.7, sensitivity and specificity of the specific AI test were 90.7% (CI 77.7 to 97.4) and 100% (CI 96.7 to 100.0), respectively, for NS1 and 14.3% (CI 4 to 32.7) and 100% (CI 96.7 to 100.0) for NS2. In patients suspected of NS with a CNS involvement (NS1 group), NS could be confirmed by the positivity of this specific AI.

CONCLUSIONS

Measurement of an intrathecal synthesis index of specific anti-T. pallidum IgG in patients with CSF inflammatory signs appears to be a valuable diagnostic test. However, in otic or ocular syphilis, presenting few CSF abnormalities, AI is not sufficient alone to confirm NS diagnosis.

TRIAL REGISTRATION

Swiss Association of Research Ethics Committees number 2019-00232.

Neurological manifestations of syphilis-HIV coinfection in South Africa

OBJECTIVE

Syphilis and HIV coinfection is highly prevalent in South Africa, and both can cause neurological complications. We describe the clinical presentation and outcome of neurosyphilis in patients with and without HIV coinfection diagnosed at a tertiary facility, Groote Schuur Hospital (GSH), in South Africa.

METHODS

We retrospectively analyzed folders of adults with positive cerebrospinal fluid (CSF) fluorescent treponemal antibody absorption test in 2018 and 2019, with follow-up data collected until 2022.

RESULTS

HIV-coinfection was identified in 35% of the 69 included patients. Patients with HIV-coinfection were more likely to be female (58% vs 25% female, p < 0.01), and present earlier (median age = 31 years vs. 40 years, p < 0.001). Neuropsychiatric manifestations (confusion, dementia, psychosis), and strokes were the commonest clinical presentations in both groups. Those with HIV-coinfection were significantly less likely to be diagnosed with neurosyphilis by the treating clinician (71% vs. 91%, p < 0.05), as were those with a negative CSF Venereal Disease Research Laboratory (74% vs. 94%, p < 0.05). Accurate diagnosis of neurosyphilis was associated with an increased 12-month survival (alive: N = 36 [63%]) relative to those who did not receive an accurate diagnosis (alive: N = 2 [17%], p < 0.05). Those who were optimally treated with antibiotics had significantly higher 12-month survival (alive: N = 33, 63%) compared to those with suboptimal treatment (alive: N = 5, 29%), p < 0.01.

CONCLUSION

Neurosyphilis presented similarly in those with and without HIV-coinfection. Accurate identification and optimal antibiotic treatment of neurosyphilis, particularly in CSF VDRL negative patients and those with HIV-coinfection, is necessary to improve patient survival.

Clinical and Laboratory Characteristics, Neuroimaging Alternations and Treatment Response of 25 HIV-Negative General Paresis Patients

Purpose

General paresis is a common type of neurosyphilis featuring progressive cognitive deterioration. The lack of a golden standard of diagnosis and its nonspecific clinical manifestations resulted in a high rate of misdiagnoses. This study aims to investigate the clinical, laboratory and radiological presentations of general paresis and enrich its knowledge for timely diagnoses.

Patients and methods

The study collected hospitalized patients admitted for general paresis from September 2002 to November 2022. Their socio-demographical and medical status, clinical presentations, cognitive assessments, laboratory and radiographical manifestations and treatment information were collected retrospectively.

Results

A total of 20 males and 5 females were included. Patients' ages ranged from 30 to 66 years (average 50.3 years). The average and median time for diagnosing general paresis was 14.1 months and 10.0 months respectively. The most frequent initial symptom is memory deterioration (68.0%). Impaired calculative ability and memory deterioration were the most frequent cognitive anomalies, as found in 50% and 45.4% of subjects during examination. The mean and median scores of MoCA was 16.7 and 17 respectively. Serological tests revealed positive TPPA for all patients and a median RPR titer at 1:64 positive. All CSF samples with TPPA and FTA-ABS results reported positivity. The MRI manifestations of general paresis include patchy or speckled hyperintensities (70.8%) and cerebral atrophy (45.8%). The most common lesioned sites in MRI were the ventricular and paraventricular area (50.0%) and temporal lobes (45.8%). For treatment, penicillin-based anti-syphilitic plans were adopted in 17 patients (68.0%).

Conclusion

The clinical features and radiological alternations of general paresis patients often exhibited diverse and nonspecific alternations. However, some specific clinical manifestations and auxiliary examinations can provide meaningful clues for the identification and differential diagnosis of this disease.

A case report of neurosyphilis coexisting with a positive MOG antibody manifested as optic neuritis

Background

Neurosyphilis refers to an infection of the central nervous system by Treponema pallidum. The clinical manifestations of neurosyphilis are diverse, making it easy to miss or misdiagnose. Anti-myelin oligodendrocyte glycoprotein antibody-associated disease is a recently defined immune-mediated inflammatory demyelinating central nervous system disease. Few studies have reported the coexistence of the two diseases.

Case presentation

This case report presents a 37 years-old male patient with neurosyphilis manifested as optic neuritis with a positive myelin oligodendrocyte glycoprotein (MOG) antibody. This patient received intravenous administration of 3.2 million units of procaine penicillin every 4 h for 2 weeks, followed by a two-week intramuscular injection of benzathine penicillin. Additionally, methylprednisolone sodium succinate was administered intravenously at 1,000 mg/day, gradually reduced to 500 mg/day and 240 mg/day every 3 days. Subsequently, prednisone tablets at a dosage of 60 mg/day were orally administered, with a gradual reduction of 5 mg/day every 3 days until reaching a dosage of 30 mg/day. The patient's visual acuity was improved after 26 days of hospitalization. However, the visual field and color vision did not. At 3 months of follow-up, the symptoms remained unchanged despite the patient continued taking oral prednisone tablets at a dosage of 30 mg/day.

Conclusion

Neurosyphilis could be a potential triggering factor for MOGAD. In patients with neurosyphilis, it is strongly recommended to perform testing for MOG antibody along with other brain disease antibodies.

Ocular syphilis mimicking Vogt-Koyanagi-Harada syndrome: a diagnostic dilemma

This case demonstrates the dilemma in the diagnosis of ocular syphilis, as it can mimic many other ocular conditions where initial steroid therapy might complicate the disease course and can worsen the infection. Also, it represents an example of anchoring bias, where a provisional diagnosis resulted in unnecessary treatment that would have worsened her clinical outcomes.

MRI of neurosyphilis with mesiotemporal lobe lesions of "knife-cut sign” on MRI: A case report and literature review

Neurosyphilis with mesiotemporal lobe lesions remains a difficult entity to diagnose, especially when it mimics herpes simplex encephalitis (HSE). Here, we report what appeared to be the first case of mesiotemporal imaging of neurosyphilis presenting as a "knife-cut" sign and mimicking HSE pathological hallmarks on imaging. The magnetic resonance imaging (MRI) changes in neurosyphilis and HSE were indistinguishable in the initial diagnosis because of the common involvement of the mesiotemporal lobe. Neurosyphilis was diagnostically confirmed by positive readings in the treponema pallidum hemagglutination assay (TPHA), rapid plasma reagin (RPR) and cerebrospinal fluid-polymerase chain reaction (CSF-PCR) tests for Treponema pallidum infection. Neurosyphilis and HSE had similar clinical features and signs on MRI, except the knife-cut sign which is a common diagnosis in HSE. Therefore, neurosyphilis with mesiotemporal changes and knife-cut signs on MRI should be evaluated in the differential diagnosis in all patients, as similar changes may also occur in HSE patients. The literature review of published articles between 1997 and 2020 was conducted to further validate our clinical observations and discuss diagnostic and treatment options for neurosyphilis with mesiotemporal lobe lesions.