KCNA2 IgG autoimmunity in neuropsychiatric diseases.

BACKGROUND: Autoantibodies against the potassium voltage-gated channel subfamily A member 2 (KCNA2) have been described in a few cases of neuropsychiatric disorders, but their diagnostic and pathophysiological role is currently unknown, imposing challenges to medical practice. DESIGN / METHODS: We retrospectively collected comprehensive clinical and paraclinical data of 35 patients with KCNA2 IgG autoantibodies detected in cell-based and tissue-based assays. Patients' sera and cerebrospinal fluid (CSF) were used for characterization of the antigen, clinical-serological correlations, and determination of IgG subclasses. RESULTS: KCNA2 autoantibody-positive patients (n = 35, median age at disease onset of 65 years, range of 16-83 years, 74 % male) mostly presented with cognitive impairment and/or epileptic seizures but also ataxia, gait disorder and personality changes. Serum autoantibodies belonged to IgG3 and IgG1 subclasses and titers ranged from 1:32 to 1:10,000. KCNA2 IgG was found in the CSF of 8/21 (38 %) patients and in the serum of 4/96 (4.2 %) healthy blood donors. KCNA2 autoantibodies bound to characteristic anatomical areas in the cerebellum and hippocampus of mammalian brain and juxtaparanodal regions of peripheral nerves but reacted exclusively with intracellular epitopes. A subset of four KCNA2 autoantibody-positive patients responded markedly to immunotherapy alongside with conversion to seronegativity, in particular those presenting an autoimmune encephalitis phenotype and receiving early immunotherapy. An available brain biopsy showed strong immune cell invasion. KCNA2 autoantibodies occurred in less than 10 % in association with an underlying tumor. CONCLUSION: Our data suggest that KCNA2 autoimmunity is clinically heterogeneous. Future studies should determine whether KCNA2 autoantibodies are directly pathogenic or develop secondarily. Early immunotherapy should be considered, in particular if autoantibodies occur in CSF or if clinical or diagnostic findings suggest ongoing inflammation. Suspicious clinical phenotypes include autoimmune encephalitis, atypical dementia, new-onset epilepsy and unexplained epileptic seizures.

Cerebrospinal fluid levels of the macrophage-specific biomarker sCD163 are diagnostic for Lyme neuroborreliosis: An observational cohort study.

OBJECTIVES: We aimed to investigate levels of the macrophage-specific marker, sCD163, in cerebrospinal fluid and plasma in patients with Lyme neuroborreliosis. We tested the diagnostic value of CSF-sCD163 and ReaScan-CXCL13 and analyzed if plasma-sCD163 could monitor treatment response. METHODS: An observational cohort study: Cohort 1-Cerebrospinal fluid from adults with neuroborreliosis (n = 42), bacterial meningitis (n = 16), enteroviral meningitis (n = 29), and controls (n = 33); Cohort 2-Plasma from 23 adults with neuroborreliosis collected at diagnosis, three, and six months. sCD163 was determined using an in-house sandwich ELISA. ReaScan-CXCL13 measured semiquantitative concentrations of CXCL13, cut-off ≥ 250 pg/ml diagnosed neuroborreliosis. Receiver Operating Characteristics analyzed the diagnostic strength. A linear mixed model including follow-up as categorical fixed effect analyzed differences in plasma-sCD163. RESULTS: CSF-sCD163 was higher in neuroborreliosis (643 µg/l) than in enteroviral meningitis (106 µg/l, p < 0.0001) and controls (87 µg/l, p < 0.0001), but not bacterial meningitis (669 µg/l, p = 0.9). The optimal cut-off was 210 µg/l, area under the curve (AUC) 0.85. ReaScan-CXCL13 had an AUC of 0.83. Combining ReaScan-CXCL13 with CSF-sCD163 increased AUC significantly to 0.89. Plasma-sCD163 showed little variation and was not elevated during the 6 months of follow-up. CONCLUSION: CSF-sCD163 is diagnostic for neuroborreliosis with an optimal cut-off of 210 µg/l. Combining ReaScan-CXCL13 with CSF-sCD163 increases AUC. Plasma-sCD163 cannot monitor treatment response.

Lyme neuroborreliosis with encephalitis: A rare case.

Encephalitis caused by Borrelia burgdorferi sensu lato is a rare clinical manifestation of Lyme neuroborreliosis and only in few cases have brain parenchymal inflammation been documented. Here, we present a case of Lyme neuroborreliosis with encephalitis with significant parenchymal inflammation on magnetic resonance imaging (MRI) in an immunosuppressed patient.

Checkpoint inhibitor induced myositis - The value of MRI STIR.

•Treatment with immune checkpoint inhibitors can cause serious adverse events.•Myositis combined with myocarditis ad adverse event have a mortality for 50%.•Early diagnosis is important for better outcome.•Employing MRI STIR can rapidly diagnose, guide biopsy, and classify cases of immune-related myositis.

Exploration of the induced cytokine responses in European Lyme neuroborreliosis: A longitudinal cohort study.

Lyme neuroborreliosis (LNB) is a prevalent tick-borne disease in Europe caused by Borrelia burgdorferi sensu lato complex. Slightly suppressed induced Th1- and Th17-responses are seen at diagnosis. The induced immune response following antibiotic therapy is unknown. We hypothesized that the immune responses normalize after completing antibiotic treatment. An observational longitudinal cohort study investigating the induced immune response in adult patients with LNB at diagnosis, three and six months after treatment. Whole blood was added to three TruCulture® (Myriad RBM, Austin, USA) tubes each containing one stimulation. An additional TruCulture® tube was without stimulation representing the in vivo activation of blood immune cells. Nine cytokines were measured using Luminex (LX200, R&D Systems, BIO-Teche LTD). Changes in immune response were analyzed with linear mixed model including follow-up as categorical fixed effect. A total of 21 patients with 55 samples were included. All had clinical improvement, but 5/21 patients reported residual symptoms after six months. The non-induced release of IL-17A and IL-1ß increased significantly from diagnosis to six month follow-up. Six months after treatment only IFN-α and TNF-α were below the reference range. Minor variations in the induced immune responses were seen during the study period. Th1- and Th17-responses continued to be low with low IFN-γ, IL-12p40, and IL-17A in multiple stimulations. Overall little dynamic was observed. The changes in the cytokine responses are most likely not linked to LNB pathogenesis and our results do not support the implementation of TruCulture® in the diagnostics or follow-up of LNB.

Antibiotic therapy of neuroborreliosis: A survey among infectious disease specialists and neurologists in Norway, Sweden, and Denmark.

INTRODUCTION: Neuroborreliosis (NB) is a prevalent tick-borne neuroinfection in Europe. To delineate current practice in antimicrobial management of adults with NB and to prioritize future trials needed to optimize treatment recommendations, a questionnaire-based survey was performed. METHODS: A self-administered Internet-based survey of NB treatment practices among specialists in infectious diseases and neurology based in Norway, Sweden, and Denmark was carried out between October 2021 and February 2022. The participants were also asked to prioritize four pre-defined research questions for randomized controlled trials (RCTs) on therapy for NB. RESULTS: In total, 290 physicians (45% female) from Norway (30%), Sweden (40%), and Denmark (30%) participated in the survey. Of the responders, 230 (79%) were infectious disease specialists and 56 (19%) were neurologists. The preferred antibiotic treatment for patients with early NB was oral doxycycline (n = 225, 78%). Intravenous (IV) penicillin, ceftriaxone, or cefotaxime for the full treatment course was favored by 12%. A preferred treatment duration of 10-14 days for patients with NB was reported by 245 respondents (85%), most common among participants from Sweden (97%). A total of 170 (59%) responders reported having local hospital guidelines on the treatment of NB, most often with recommendation of oral doxycycline (92%) for 10-14 days (90%) as first line treatment. The prioritization score for future RCTs was highest for adjunctive prednisone therapy in NB patients with facial palsy (median 5; IQR 4-6) and for placebo versus repeated antibiotics in patients with persistent symptoms after completed antibiotic therapy for NB (median 5, IQR 3-6). CONCLUSION: In Sweden, all respondents preferred treating NB with oral doxycycline for 10-14 days, whereas 5% in Norway and 19% in Denmark still treat NB with IV antibiotics for the entire treatment course. RCTs to define the role of adjunctive prednisolone in NB patients with facial palsy and repeated antibiotics in patients with persistent symptoms are prioritized for future research.

A case report of immune checkpoint inhibitor-related steroid-refractory myocarditis and myasthenia gravis-like myositis treated with abatacept and mycophenolate mofetil.

BACKGROUND: Immune checkpoint inhibitor (ICI)-related myocarditis is an uncommon but potentially fatal immune-related adverse event. Corticoid-resistant myocarditis induced by ICI is an important therapeutic challenge. CASE SUMMARY: Here, we present a case of steroid-refractory ICI-related myocarditis and myositis treated with abatacept and mycophenolate mofetil (MMF). A 57-year-old male with metastatic renal cell carcinoma was diagnosed with immune-related myocarditis and myasthenia gravis-like myositis after first dose of combination ICIs with nivolumab (anti-programmed cell death-1) plus ipilimumab (anti-cytotoxic T-lymphocyte-associated antigen-4). Twelve days after ICI he was admitted to the hospital due to palpitations, headache, and pain in the extremities. Laboratory findings revealed elevated inflammatory markers and cardiac enzymes. Electrocardiogram showed first-degree atrioventricular (AV) block and right bundle branch block which developed into complete heart block within 48 h. Because of clinical and paraclinical deterioration despite immediate initiation of methylprednisolone abatacept and MMF was added. Following, gradual subjective improvement and termination of arrhythmia led to discharge of the patient from the hospital 6 weeks after the introduction of ICI. DISCUSSION: The key treatment of ICI-related myocarditis is glucocorticoid. For steroid-refractory myocarditis supplementary immune suppressive agents are recommended. Yet, data still relies on case reports and case series, due to lack of prospective studies. In this case, the use of abatacept and MMF led to resolution of steroid-resistant ICI-related myocarditis and myositis.

[Reversible hemifacial spasm due to non-ketotichyperglycaemia].

Hemifacial spasm (HFS) is a movement disorder affecting the facial muscles and is primarily due to a lesion related to the seventh cranial nerve or the brainstem. In this case report, a 71-year-old man had a rare presentation of acute onset HFS due to non-ketotic hyperglycemia. Type 2 diabetes was diagnosed during hospital admission. A brain magnetic resonance imaging showed a hyperintense lesion in the contralateral basal ganglia. Full remission of symptoms was seen within days after start of antidiabetic agents. Hyperglycaemic induced movement disorder is an important differential diagnosis to HFS and has a good prognosis.

[Hepatits E virus can cause neurological disorders].

Hepatitis E virus (HEV) is a common cause of acute hepatitis worldwide and is endemic in Europe, including Denmark. Several non-liver manifestations have been apparent, the most important of which is neurological, including neuralgic amyotrophy and Guillain-Barré syndrome as summarised in this review. Certain neurological presentations and patients with unexplained mild to moderate increase in liver enzymes, should lead to the consideration of a HEV-related condition. Many research questions regarding HEV-related neurological injury remain unanswered and need further investigation.

[Hepatitis E-related meningoradiculitis].

Hepatitis E virus (HEV) is the most common cause of acute clinical hepatitis in the world and can cause extrahepatic disease including the nervous system. This is a case report of two patients illustrating this disorder. One patient was a 69-year-old man with painless affection of both brachial plexuses, and the other patient was a 61-year-old man with painful right brachial plexus affection, headache and cognitive problems. Both had pleocytosis in cerebrospinal fluid and tested positive for HEV immunoglobulin (Ig) G and IgM in blood, and the first also in blood with PCR analysis. No other infectious agents were identified. Symptoms improved over months.

Case report: 'AARS2 leukodystrophy'.

BACKGROUND: Mitochondrial alanyl-tRNA synthetase 2 gene (AARS2) related disease is a rare genetic disorder affecting mitochondrial metabolism, leading to severe cardiac disease in infants or progressive leukodystrophy in young adults. The disease is considered ultra-rare with only 39 cases of AARS2-leukodystrophy previously reported. CASE PRESENTATION: We present the case of a young man of consanguineous heritage suffering from cognitive decline and progressive spasticity as well as weakness of the proximal musculature. Utilizing MRI and whole genome sequencing, the patient was diagnosed with a homozygous AARS2 missense variant (NM_020745.3:c.650C > T; p.(Pro217Leu)) and a homozygous CAPN3 variant (NM_000070.2: c.1469G > A; p.(Arg490Gln)), both variants have previously been identified in patients suffering from AARS2 related leukodystrophy and limb-girdle muscular dystrophy, respectively. CONCLUSIONS: This case report presents a case of homozygous AARS2 leukodystrophy and serves to highlight the importance of whole genome sequencing in diagnosing rare neurological diseases as well as to add to the awareness of adult onset leukodystrophies.

Case Report: Longitudinal Extensive Transverse Myelitis With Novel Autoantibodies Following Two Rounds of Pembrolizumab.

A 63-year-old male with metastatic non-small cell lung cancer developed longitudinal extensive transverse myelitis (LETM) following two cycles of Pembrolizumab, an immune checkpoint inhibitor (ICI) targeting the programmed cell death receptor 1 (PD-1). Magnetic resonance imaging (MRI) showed centromedullary contrast enhancement at several levels, cerebrospinal fluid (CSF) cytology showed lymphocytic pleocytosis, and indirect immunofluorescence assay (IFA) on the primate cerebellum, pancreas, and intestine revealed strong binding of neuronal autoantibodies to unknown antigens. CSF C-X-C motif ligand 13 (CXCL13) was elevated. The patient was treated with plasma exchange (PEX) and intravenous (i.v.) methylprednisolone (MP) 1 g/day for 5 days followed by oral (p.o.) MP 100 mg/day for 10 days with clinical and radiological response. However, after discontinuation of MP, LETM relapsed and the patient developed paralytic ileus presumably due to autoimmune enteropathy and suffered a fatal gastrointestinal sepsis. Findings of novel neuronal autoantibodies and highly elevated CXCL13 in CSF suggest that the severe neurological immune-related adverse event (nirAE) was B-cell mediated contrary to the commonly assumed ICI-induced T-cell toxicity. An individual evaluation of the underlying pathophysiology behind rare nirAEs is essential for choosing treatment regimens and securing optimal outcome.

Stimulated Immune Response by TruCulture® Whole Blood Assay in Patients With European Lyme Neuroborreliosis: A Prospective Cohort Study.

Introduction: Borrelia burgdorferi sensu lato complex (B. burgdorferi) can cause a variety of clinical manifestations including Lyme neuroborreliosis. Following the tick-borne transmission, B. burgdorferi initially evade immune responses, later symptomatic infection is associated with occurrence of specific antibody responses. We hypothesized that B. burgdorferi induce immune hyporesponsiveness or immune suppression and aimed to investigate patients with Lyme neuroborreliosis ability to respond to immune stimulation. Methods: An observational cohort study investigating the stimulated immune response by standardized whole blood assay (TruCulture®) in adult patients with Lyme neuroborreliosis included at time of diagnosis from 01.09.2018-31.07.2020. Reference intervals were based on a 5-95% range of cytokine concentrations from healthy individuals (n = 32). Patients with Lyme neuroborreliosis and references were compared using Mann-Whitney U test. Heatmaps of cytokine responses were generated using the webtool Clustvis. Results: In total, 22 patients with Lyme neuroborreliosis (19 definite, 3 probable) were included. In the unstimulated samples, the concentrations of cytokines in patients with Lyme neuroborreliosis were comparable with references, except interferon (IFN)-α, interleukin (IL)-17A, IL-1ß and IL-8, which were all significantly below the references. Patients with Lyme neuroborreliosis had similar concentrations of most cytokines in all stimulations compared with references. IFN-α, IFN-γ, IL-12 and IL-17A were lower than references in multiple stimulations. Conclusion: In this exploratory cohort study, we found lower or similar concentrations of circulating cytokines in blood from patients with Lyme neuroborreliosis at time of diagnosis compared with references. The stimulated cytokine release in blood from patients with Lyme neuroborreliosis was in general slightly lower than in the references. Specific patterns of low IL-12 and IFN-γ indicated low Th1-response and low concentrations of IL-17A did not support a strong Th17 response. Our results suggest that patients with Lyme neuroborreliosis elicit a slightly suppressed or impaired immune response for the investigated stimulations, however, whether the response normalizes remains unanswered.

[Neurological adverse effects of cancer therapy with checkpoint inhibitors].

Treatment with checkpoint inhibitors has revolutionised the treatment of many different cancers with a significant improvement in cancer survival. However, a different type of adverse effects is seen compared to standard chemotherapy called immune-related adverse effects (irAE). In this review, we give recommendations on how to diagnose and treat the most common and severe neurologic irAE. We advise clinicians to be cautious to classify neurologic irAE as well-known nosologic entities, since their presentation, cause and treatment often is different.

[Severe cerebral haemodynamic impairment treated with bypass surgery].

Cerebral hypoperfusion due to steno-occlusive large artery disease poses a diagnostic challenge. This is a case report of a 72-year-old woman, presenting with recurring paroxysmal right-sided hemiparesis, dysphasia and occasionally limb-shaking transient ischaemic attacks, especially during orthostatic challenge. The condition was initially misdiagnosed as focal epilepsy. A workup revealed a left-sided carotid artery occlusion and a haemodynamic failure in the carotid distribution, seen on a 15O-H2O PET acetazolamid scan. The patient was successfully treated with an extracranial-intracranial bypass surgery.

[Atypical aura caused by a stroke in a 42-year-old man with migraine with aura].

Ischaemic stroke in persons with migraine may present with aura-like symptoms. In this case report a 42-year-old man with migraine with aura presented with a change in usual aura including visual loss and disorientation. A brain MRI revealed ischaemic stroke in precuneus compatible with these symptoms. We discuss the pathophysiology, the causes and the secondary prophylaxis in persons with migraine with aura and stroke.

[Reversible cerebral vasoconstriction syndrome causing acute-onset headache].

Reversible cerebral vasoconstriction syndrome is caused by narrowing of cerebral arteries. The cardinal symptom is relapsing acute-onset headache also known as thunderclap headache, which may be accompanied by neurologic deficits. This is a case report of a 61-year-old woman with CT angiography-verified reversible cerebral vasoconstriction syndrome. We discuss the diagnostic work-up, i.e. lumbar puncture including test for xanthochromia and important brain imaging, differential diagnoses and treatment of the most important causes of thunderclap headache.

[Carbon monoxide poisoning and development of delayed neuropsychiatric syndrome in a 77-year-old woman].

This case report describes carbon monoxide (CO) poisoning in a woman. CO is a toxic, odourless and colourless gas. Delayed cognitive sequelae have been described in up to 40% of patients with significant CO poisoning. A 77-year-old woman suffered from severe smoke- and CO poisoning and received hyperbaric O2 therapy, but she continued to have memory impairment and unsteady gait at day 26. Brain MRI showed diffuse white matter lesions in both hemispheres with increased signal on diffusion-weighted imaging. Diagnosis, pathogenesis and treatment of CO poisoning are discussed.

[Tick-borne encephalitis-associated meningoradiculoneuritis acquired in the south-western part of Denmark].

This is a case report of a 68-year-old woman, who developed malaise after an insect bite. Symptoms subsided, and over weeks progressing difficulty with walking, ataxia and universal areflexia developed. A lumbar puncture showed mononuclear pleocytosis and moderately raised protein levels with no detected viral agents. An MRI of the spinal cord showed leptomeningeal contrast attenuation distally. Serum samples were positive for anti-tick-borne encephalitis (TBE) IgM-antibodies, but not IgG, and showed seroconversion. TBE is endemic in areas of Central Europe and Scandinavia but has earlier only been shown in the eastern part of Denmark.