Autoantibody-mediated encephalitis: Not just paraneoplastic, not just limbic, and not untreatable

The Current State of Knowledge on Baggio–Yoshinari Syndrome (Brazilian Lyme Disease-like Illness): Chronological Presentation of Historical and Scientific Events Observed over the Last 30 Years

Baggio–Yoshinari Syndrome (BYS) is an emerging Brazilian tick-borne infectious disease that clinically mimics Lyme Disease (LD) present in the Northern Hemisphere. LD is caused by spirochetes belonging to the Borrelia burgdorferi sensu lato complex and transmitted by Ixodid ticks of complex Ixodes rticinus. On the contrary, BYS is transmitted by hard Ixodid ticks of the genera Amblyomma, Rhipicephalus and Dermacentor. In 1992, the first cases of BYS were described in patients that developed EM rash, flu-like symptoms and arthritis after tick bite episodes. Since these findings, research in BYS has been developing for more than 30 years and shows that its epidemiological, clinical and laboratorial features are different from LD. Borrelia burgdorferi was never isolated in Brazil. In addition, specific serologic tests have shown little positivity. Furthermore, peripheral blood analysis of patients using electron microscopy exhibited structures resembling spirochete-like microorganisms or the latent forms of spirochetes (L form or cell wall deficient bacteria). For these reasons, Brazilian zoonosis was defined as an exotic and emerging Brazilian infectious disease, transmitted by ticks not belonging to the Ixodes ricinus complex, caused by latent spirochetes belonging to the B. burgdorferi sensu lato complex with atypical morphology. The Brazilian ecosystem, combined with its ticks and reservoir biodiversity, possibly contributed to the origin of this new zoonosis, which emerged as a result of the passage of B. burgdorferi through exotic vectors and reservoirs.

Acute cerebral atrophy in autoimmune encephalitis complicated by haemophagocytic lymphohistiocytosis

Autoimmune encephalitis is a disease characterised by neural-specific antibodies. This case report presents a 20-year-old young man with a recent history of suspected viral encephalitis who presented with recurrent fevers and episodes of confusion. He was found to have anti-N-methyl-D-aspartate receptor (NMDAR) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid 1 receptor (AMPAR1) positive autoantibodies and was diagnosed with autoimmune encephalitis. He subsequently developed global cerebral atrophy and was found to meet diagnostic criteria for haemophagocytic lymphohistiocytosis (HLH). This patient's presentation was consistent with existing literature showing that autoimmune encephalitis may develop after an initial viral meningoencephalitis. However, concurrent anti-NMDAR and anti-AMPAR1 positive autoimmune encephalitis has not been reported in literature to date, and this case report represents one instance of its presentation. We speculate that multiple antibodies against neural surface antigens may increase the risk for systemic immune activation leading to HLH and acute cerebral atrophy.

Paraneoplastic and autoimmune encephalitis: Alterations of mood and emotion

Autoimmune encephalitis often produces signs and symptoms that appear to be at the interface between neurology and psychiatry. Since psychiatric symptoms are often prominent, patients are often first seen in a psychiatric setting. Therefore it is important that psychiatrists, as well as neurologists, be able to recognize autoimmune encephalitis, a task that is often difficult. Early diagnosis of autoimmune encephalitis is crucial as this will usually result in a better outcome for the patient. This chapter provides an introduction to various autoimmune encephalitides and describes their pathophysiology and the possible associated neuropsychiatric, neuropsychological (cognitive), and neurological (sensory-motor) signs and symptoms. This chapter also reviews the possible treatments of these associated signs and symptoms.

Consequences of physical distancing emanating from the COVID-19 pandemic: An Australian perspective

The sobering reality of the COVID-19 pandemic is that it has brought people together at home at a time when we want them apart in the community. This will bring both benefits and challenges. It will affect people differently based upon their age, health status, resilience, family support structures, and socio-economic background. This article will assess the impact in high income countries like Australia, where the initial wave of infection placed the elderly at the greatest risk of death whilst the protective measures of physical distancing, self-isolation, increased awareness of hygiene practices, and school closures with distance learning has had considerable impact on children and families acutely and may have ramifications for years to come.

GABABR-Mediated Paraneoplastic Limbic Encephalitis Due To Thymic Small Cell Carcinoma

We report the case of a 55-year-old male who presented with several weeks of seizures, agitation, progressive confusion, and receptive aphasia. CSF showed a monocytic pleocytosis and tested positive for GABA_B receptor autoantibodies. Pathological examination of an excisional mediastinal lymph node biopsy showed thymic small cell carcinoma, supporting a diagnosis of paraneoplastic limbic encephalitis (PLE). PLE is a subtype of limbic encephalitis and is associated with an array of autoantibodies. Neurologic symptoms related to PLE may precede the detection of the primary cancer. Recognition of the constellation of clinical features of limbic encephalitis should prompt initiation of diagnostic testing for this condition as well as evaluation for an underlying malignancy. A review of the literature reveals that this is the first case report of a patient with thymic small cell cancer presenting with PLE.

A Case Report of Seronegative Limbic Encephalitis

Most patients with autoimmune encephalitis do not present with well-described symptoms. Demographic data and information regarding co-morbidities could help in diagnosing the underlying disorder, but a definitive diagnosis is made by the result of autoimmune antibodies. Limbic encephalitis (LE), a variant of autoimmune encephalitis, is the inflammation of the limbic system of the brain. The disorder presents with the rapid development of confusion, working memory impairment, mood changes, and often seizures. LE could have paraneoplastic or non-paraneoplastic etiology. We present the case of a 15-year-old girl with seronegative LE, who presented with cognitive decline and seizures. This condition is rare, and therefore poses a great challenge in diagnosis at an early stage.

Autoimmune encephalitis positive for both anti-γ-aminobutyric acid B receptor and anticollapsin response-mediator protein 5 antibodies: A case report

RATIONALE

Autoimmune encephalitis (AE) is a heterogeneous group of recently identified disorders. Despite severe and even prolonged neurologic deficits, dramatic improvements may occur with proper immunotherapy in some patients with AE. Antineuronal antibodies have been discovered in patients' serum and cerebrospinal fluid (CSF). However, AE with multiple antineuronal antibodies is rare. To date, there are no published reports of AE with both anti-γ-aminobutyric acid B receptor (GABABR) and anticollapsin response-mediator protein 5 (CV2) antibodies.

PATIENT CONCERNS

We describe a 46-year-old man who presented with seizures, working memory deficits, and visual hallucinations. We detected anti-CV2 and anti-GABABR antibodies in his serum and CSF. Brain magnetic resonance imaging (MRI) revealed patchy abnormal signals in his left temporal lobe and hippocampus. The patient's symptoms improved after receiving intravenous immunoglobulin injections and glucocorticoids, but his condition relapsed within 4 months, and he was readmitted to our hospital. Repeated MRI scans revealed new lesions in his right temporal lobe and hippocampus.

DIAGNOSIS

The AE diagnosis was established from the results of the preliminary physical examination, the laboratory tests, and the imaging findings.

INTERVENTIONS

The patient received intravenous immunoglobulins and glucocorticoids.

OUTCOMES

We followed the patient for 9 months from the date of the patient's second hospital discharge. He experienced no seizures during this period, but his short-term memory deficits and visual hallucinations were not completely alleviated.

LESSONS

Coexisting anti-CV2 and anti-GABABR antibodies may have synergistic effects and worsen the clinical syndrome. AE with multiple antineuronal antibodies may be relapse-prone. Further studies investigating the relationship between anti-CV2 and anti-GABABR antibodies are warranted.

Three case studies of nonparaneoplastic limbic encephalitis (NPLE) in young adult males: Onset, course, and recovery following rehabilitation services

Limbic encephalitis (LE) is a rare neurological disorder characterized by inflammation of the brain caused by autoimmunity or infection. LE has been a difficult to define and diagnose disorder due to the insidious and nonspecific (e.g., irritability, low mood, short-term memory complaints) presentation of early symptoms, as well as inconsistent findings on neuroimaging, lumbar puncture serum analysis, and electroencephalogram. Seizures, memory problems, and psychiatric disturbance are among the earliest and most prominent clinical features. This manuscript describes three adolescent males who developed LE and became psychotic, needed inpatient care, were trialed on various psychotropic medications, and exhibited lingering cognitive and psychiatric issues, though generally had very positive recoveries and return to community activities. There was no history of psychiatric disturbance, developmental disorder, or learning difficulties in any of these three young men. Two of the three cases exhibited a long, insidious symptom onset. None of the adolescents benefitted from antipsychotic medications and did not begin to experience improvement and eventual recovery until intravenous immunoglobulin (IVIG) was added to their treatment regimen. Neuropsychological consultation and team education was helpful in each of these cases. Neuropsychological findings for each individual are presented.

Added diagnostic utility of PET in a patient with subacute encephalopathy and small-cell lung cancer

Diagnosis of paraneoplastic neurologic disorder (PND) synthesizes the clinical picture (including the temporal relationship to the cancer diagnosis), detection of onconeural antibodies and exclusion of alternative causes. The mainstay of brain imaging of PNDs is MRI. There is also an increasingly recognized role of PET using radiotracer ¹⁸F-Fluorodeoxyglucose (FDG) in the evaluation of the brain. We describe a 67-year-old female with a 50-year smoking history and small-cell lung cancer developing subacute encephalopathy with MRI and PET abnormalities identifying paraneoplastic encephalitis. PET may complement conventional tools in diagnosing a subset of patients with PND.