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.

Secondary immunoreaction in patients with neurosyphilis and its relevance to clinical outcomes

Background and purpose

Several reported cases of autoimmune conditions such as anti-NMDAR encephalitis and neuromyelitis optica (AQP4) have been considered to be potentially secondary to Treponema pallidum infection. Since the role of immune impairment in neurosyphilis is unclear, in this retrospective study, we examined the correlation of the immune impairment in patients with neurosyphilis with their clinical characteristics and outcomes.

Methods

Clinical information was collected from patients with neurosyphilis in our center from January 2019 to December 2021. Cerebrospinal fluid (CSF) samples were subjected to indirect immunofluorescence tissue-based assay (IIF-TBA) on mouse brain sections and cell-based assay (CBA). The clinical characteristics and treatment outcomes of TBA-positive and-negative patients were compared.

Results

A total number of 81 patients diagnosed with neurosyphilis were included. The results of the CBA tests showed that three cases had anti-NMDAR, AQP4, or GAD65 antibodies, respectively. By TBA test, 38 patients (38/81, 46.9%) had positive immunostains, including staining of neuronal cells in 21 cases (21/38, 55.3%), glial cells in 11 cases (11/38, 28.9%), and neuronal and glial cells in six cases (6/38, 15.8%). We then compared the clinical characteristics and treatment outcomes between the TBA-positive and-negative patients and found that TBA-positive staining was significantly correlated with syphilis antibody titers (p = 0.027 for serum and p = 0.006 for CSF) and head MRI abnormalities (p < 0.001 for parenchymal abnormalities and p = 0.013 for white matter lesions). The cognitive prognosis of TBA-positive neurosyphilis patients was significantly worse than that of TBA-negative patients (p < 0.001).

Conclusion

The correlation between the TBA results and clinical data of our neurosyphilis patients imply the presence of secondary immune damage, which affected their prognosis. Therefore, TBA can be used as an additional biomarker for neurosyphilis patient prognosis.

Ocular Syphilis Presenting As Non-arteritic Anterior Ischemic Optic Neuropathy

Syphilis is a sexually transmitted disease caused by the spirochetal bacteria Treponema pallidum. It can cross the blood-brain barrier within days of the infection, causing neurosyphilis and ocular syphilis at any stage of the disease. Ocular syphilis can manifest in any part of the eye but usually as posterior uveitis and pan-uveitis or various types of inflammatory or immune-mediated optic neuritis. Misdiagnosing ocular syphilis as a non-infectious disease has been reported even when seen by ophthalmologists due to the wide variety of possible presentations. In this case report, we describe a case of ocular syphilis that presented with a non-arteritic anterior ischemic optic neuropathy (NA-AION), which to our knowledge, has not been described before in the literature.

Cases of neuromyelitis optica spectrum disorder from the East Africa region, highlighting challenges in diagnostics and healthcare access

Background

Neuromyelitis optica spectrum disorder (NMOSD) is an auto-immune disease of the central nervous system (CNS) associated with the IgG-antibody against aquaporin-4 (AQP4-IgG). There is little published epidemiology of NMOSD from sub-Saharan Africa (SSA).

Methods

We retrospectively collated NMOSD cases admitted to our tertiary regional neurology centre.

Results

We identified 11 cases (10 female, average age 30 years). 64% (7/11) were seropositive for AQP4-IgG, measured using indirect immunofluorescence. The remaining cases could either not afford tests, or had pathognomonic radiological features. 57% (4/7) of seropositive cases had concurrent/recent CNS infection. All patients were treated with high-dose intravenous methylprednisolone (IVMP), and 36% (4/11) also had plasma exchange. Only 55% (6/11) of the patients were seen by a neurologist at presentation: they had less relapses (1.3 vs 2.4), less diagnostic delay (2.3 vs 7.4 months), and were less disabled at the end of our review period. 10 cases were immunosuppressed long-term: 60% on mycophenolate, 30% azathioprine, and one on rituximab.

Conclusion

Our study is the largest case series of NMOSD from the East Africa region. Patients faced challenges of access to appropriate and affordable testing, and timely availability of a neurologist at onset, which had impacts on their functional outcomes. The majority of the seropositive cases had recent/concurrent CNS infections, suggesting triggered auto-immunity.

The history of neuromyelitis optica. Part 2: 'Spinal amaurosis', or how it all began

Neuromyelitis optica (NMO) was long considered a clinical variant of multiple sclerosis (MS). However, the discovery of a novel and pathogenic anti-astrocytic serum autoantibody targeting aquaporin-4 (termed NMO-IgG or AQP4-Ab), the most abundant water channel protein in the central nervous system, led to the recognition of NMO as a distinct disease entity in its own right and generated strong and persisting interest in the condition. NMO is now studied as a prototypic autoimmune disorder, which differs from MS in terms of immunopathogenesis, clinicoradiological presentation, optimum treatment, and prognosis. While the history of classic MS has been extensively studied, relatively little is known about the history of NMO. In Part 1 of this series we focused on the late 19th century, when the term 'neuromyelitis optica' was first coined, traced the term's origins and followed its meandering evolution throughout the 20th and into the 21st century. Here, in Part 2, we demonstrate that the peculiar concurrence of acute optic nerve and spinal cord affliction characteristic for NMO caught the attention of physicians much earlier than previously thought by re-presenting a number of very early cases of possible NMO that date back to the late 18th and early 19th century. In addition, we comprehensively discuss the pioneering concept of 'spinal amaurosis', which was introduced into the medical literature by ophthalmologists in the first half of the 19th century.

Concurrent aquaporin-4-positive NMOSD and neurosyphilis: A case report

Neuromyelitis optica spectrum disorder (NMOSD) is a common neuroinflammatory demyelinating disease associated with aquaporin-4 (AQP4) antibody in the central nervous system. Neurosyphilis is a neurological disease caused by Treponema pallidum infection. NMOSD commonly occurs concurrently with autoimmune diseases. However, they have rarely been associated with infectious diseases. In this report we describe a rare case of concurrent AQP4-positive NMOSD and neurosyphilis. A 60-year-old man was admitted to our hospital with a complaint of progressive weakness in his legs for one month. T2-weighted magnetic resonance images of the spinal cord showed longitudinal extensive lesions at C7-T7. The rapid plasma reagin test and T. pallidum particle agglutination assay performed using patient serum and cerebrospinal fluid (CSF) were positive. Additionally, the AQP4-immunoglobulin (Ig) G was detected in the serum and CSF. The patient's symptom gradually improved after penicillin and methylprednisolone treatment. This case report highlights the possibility of the presence of an infectious disease in patients with NMOSD.

Neuromyelitis optica in patients with coexisting human immunodeficiency virus infections

Two patients with known human immunodeficiency virus (HIV) infections and receiving antiretroviral treatment developed neuromyelitis optica (Devic’s disease). One patient tested positive for serum aquaporin-4 immunoglobulin G antibodies. Both patients were treated with high dose pulsed intravenous methylprednisolone followed by standard sessions of plasma exchange both at the onset attack and during disease relapses. For maintenance therapy, one patient received rituximab infusions and the second patient received mycophenolate mofetil orally. Despite treatment, both patients are currently wheelchair-bound due to severe paraparesis. Neuromyelitis optica can occur in the course of HIV infection and poses an ongoing therapeutic challenge.

Idiopathic transverse myelitis and neuromyelitis optica: clinical profiles, pathophysiology and therapeutic choices

Transverse myelitis is a focal inflammatory disorder of the spinal cord which may arise due to different etiologies. Transverse myelitis may be idiopathic or related/secondary to other diseases including infections, connective tissue disorders and other autoimmune diseases. It may be also associated with optic neuritis (neuromyelitis optica), which may precede transverse myelitis. In this manuscript we review the pathophysiology of different types of transverse myelitis and neuromyelitis optica and discuss diagnostic criteria for idiopathic transverse myelitis and risk of development of multiple sclerosis after an episode of transverse myelitis. We also discuss treatment options including corticosteroids, immunosuppressives and monoclonal antibodies, plasma exchange and intravenous immunoglobulins.

Neuromyelitis optica in a patient with pemphigus foliaceus

Neuromyelitis optica (NMO, also eponymously known as Devic's disease) is an immune-mediated demyelinating disease of the central nervous system that can lead to significant disability. Pediatric NMO is a rare disorder often reported after an infection. The authors report a 16 year-old female patient with pemphigus foliaceus who developed subacute optic neuritis followed by cervical transverse myelitis. Restricted distribution of the lesions in the optic nerve and spinal cord was confirmed by ophthalmological evaluation and magnetic resonance imaging of the brain and spinal cord. She was started on intravenous methylprednisolone and then given a maintenance oral prednisone. Subsequently, she was treated with a nonsteroidal immunosuppressant, mycophenolate mofetil, with a target dose of 1000 mg twice a day. Over the course of months, patient noted significant recovery of previous deficits and resolution of the cervical cord enhancement, expansion and cystic dilatation that was previously seen. This case is noteworthy for being the first patient reported with neuromyelitis optica associated with pemphigus foliaceus.

The clinical spectrum and immunobiology of parainfectious neuromyelitis optica (Devic) syndromes

In a subgroup of patients with neuromyelitis optica (NMO), a severe inflammatory demyelinating disorder of autoimmune origin characterized by recurrent attacks of optic neuritis and longitudinally extensive transverse myelitis, a parainfectious pathogenesis may play a central role. We systematically evaluated such reports in the literature published between 1975 and 2009 in order to characterize parainfectious NMO syndromes. Identified were 25 cases, whereof 11 were in association with viral and 14 with bacterial pathogens. Sufficient clinical and paraclinical information was available in 16 patients (11 women). Median age was 8 years for children and 32 years for adults. Acute febrile illness preceding or in close relation with neurological symptoms was most common and the association with varicella-zoster virus and Mycobacterium pneumonia most frequent. In the majority, the course was monophasic (88%) and disability sustained (with complete recovery in only 25%). Seven patients fulfilled the revised NMO diagnosis criteria of 2006; none was seropositve for aquaporin-4 antibodies. Immune mechanisms potentially involved in parainfectious NMO syndromes include bystander activation, molecular mimicry, and the exacerbation of a pre-existing central nervous system (CNS) disorder by a systemic infection. However, current studies are not sufficient to define the place of parainfectious NMO syndromes within the spectrum of inflammatory disorders of the CNS.

Neuromyelitis optica pathogenesis and aquaporin 4

Neuromyelitis optica (NMO) is a severe, debilitating human disease that predominantly features immunopathology in the optic nerves and the spinal cord. An IgG1 autoantibody (NMO-IgG) that binds aquaporin 4 (AQP4) has been identified in the sera of a significant number of NMO patients, as well as in patients with two related neurologic conditions, bilateral optic neuritis (ON), and longitudinal extensive transverse myelitis (LETM), that are generally considered to lie within the NMO spectrum of diseases. NMO-IgG is not the only autoantibody found in NMO patient sera, but the correlation of pathology in central nervous system (CNS) with tissues that normally express high levels of AQP4 suggests NMO-IgG might be pathogenic. If this is the case, it is important to identify and understand the mechanism(s) whereby an immune response is induced against AQP4. This review focuses on open questions about the "events" that need to be understood to determine if AQP4 and NMO-IgG are involved in the pathogenesis of NMO. These questions include: 1) How might AQP4-specific T and B cells be primed by either CNS AQP4 or peripheral pools of AQP4? 2) Do the different AQP4-expressing tissues and perhaps the membrane structural organization of AQP4 influence NMO-IgG binding efficacy and thus pathogenesis? 3) Does prior infection, genetic predisposition, or underlying immune dysregulation contribute to a confluence of events which lead to NMO in select individuals? A small animal model of NMO is essential to demonstrate whether AQP4 is indeed the incipient autoantigen capable of inducing NMO-IgG formation and NMO. If the NMO model is consistent with the human disease, it can be used to examine how changes in AQP4 expression and blood-brain barrier (BBB) integrity, both of which can be regulated by CNS inflammation, contribute to inductive events for anti-AQP4-specific immune response. In this review, we identify reagents and experimental questions that need to be developed and addressed to enhance our understanding of the pathogenesis of NMO. Finally, dysregulation of tolerance associated with autoimmune disease appears to have a role in NMO. Animal models would allow manipulation of hormone levels, B cell growth factors, and other elements known to increase the penetrance of autoimmune disease. Thus an AQP4 animal model would provide a means to manipulate events which are now associated with NMO and thus demonstrate what set of events or multiplicity of events can push the anti-AQP4 response to be pathogenic.

Devic’s neuromyelitis optica: a critical review

Devic's neuromyelitis optica (NMO) is an idiopathic inflammatory demyelinating and necrotizing disease characterized by predominant involvement of the optic nerves and spinal cord. In Asian countries relapsing NMO has been known as opticospinal multiple sclerosis. It has long been debated if NMO is a variant of multiple sclerosis (MS) or a distinct disease. Recent studies have shown that NMO has more frequently a relapsing course, and results from attack to aquaporin-4 which is the dominant water channel in the central nervous system, located in foot processes of the astrocytes. Distinctive pathological features of NMO include perivascular deposition of IgG and complement in the perivascular space, granulocyte and eosinophil infiltrates and hyalinization of the vascular walls. These features distinguish NMO from other demyelinating diseases such as MS and acute demyelinating encephalomyelopathy. An IgG-antibody that binds to aquaporin-4, named NMO-IgG has high sensitivity and specificity. Magnetic resonance imaging (MRI) studies have revealed that more frequently there is a long spinal cord lesion that extends through three or more vertebral segments in length. Brain MRI lesions atypical for MS are found in the majority of cases. Treatment in the acute phase includes intravenous steroids and plasma exchange therapy. Immunosupressive agents are recommended for prophylaxis of relapses.