Anti-neurochondrin antibody as a biomarker in primary autoimmune cerebellar ataxia-a case report and review of the literature.

BACKGROUND AND PURPOSE: Neuronal autoantibodies can support the diagnosis of primary autoimmune cerebellar ataxia (PACA). Knowledge of PACA is still sparce. This article aims to highlight the relevance of anti-neurochondrin antibodies and possible therapeutical consequences in people with PACA. METHODS: This is a case presentation and literature review of PACA associated with anti-neurochondrin antibodies. RESULTS: A 33-year-old man noticed reduced control of the right leg in May 2020. During his first clinic appointment at our institution in September 2021, he complained about gait imbalance, fine motor disorders, tremor, intermittent diplopia and slurred speech. He presented a pancerebellar syndrome with stance, gait and limb ataxia, scanning speech and oculomotor dysfunction. Within 3 months the symptoms progressed. An initial cerebral magnetic resonance imaging, June 2020, was normal, but follow-up imaging in October 2021 and July 2022 revealed marked cerebellar atrophy (29% volume loss). Cerebrospinal fluid analysis showed lymphocytic pleocytosis of 11 x 103 /L (normal range 0-4) and oligoclonal bands type II. Anti-neurochondrin antibodies (immunoglobulin G) were detected in serum (1:10,000) and cerebrospinal fluid (1:320, by cell-based indirect immunofluorescence assay and immunoblot, analysed by the EUROIMMUN laboratory). After ruling out alternative causes and neoplasia, diagnosis of PACA was given and immunotherapy (steroids and cyclophosphamide) was started in January 2022. In March 2022 a stabilization of disease was observed. CONCLUSION: Cerebellar ataxia associated with anti-neurochondrin antibodies has only been described in 19 cases; however, the number of unrecognized PACAs may be higher. As anti-neurochondrin antibodies target an intracellular antigen and exhibit a mainly cytotoxic T-cell-mediated pathogenesis, important therapeutic implications may result. Because of the severe and rapid clinical progression, aggressive immunotherapy was warranted. This case highlights the need for rapid diagnosis and therapy in PACA, as stabilization and even improvement of symptoms are attainable.

Anti-kelchlike protein 11 antibody-associated encephalitis: Two case reports and review of the literature.

BACKGROUND AND PURPOSE: Kelchlike protein 11 antibodies (KLHL11-IgGs) were first described in 2019 as a marker of paraneoplastic neurological syndromes (PNSs). They have mostly been associated with testicular germ cell tumors (tGCTs). METHODS: Two patients with KLHL11-IgG encephalitis are reported, and the literature is comprehensively reviewed. RESULTS: Patient 1 had been in remission from a tGCT 10 years prior. He developed episodic vertigo and diplopia progressing over a few days. Treatment with corticosteroids (CSs) was started a few days after symptom onset. Patient 2 had transient diplopia, which resolved spontaneously. Visual problems persisted for 7 months, when he additionally developed a progressive cerebellar syndrome. One year after onset, CS treatment was started. Initial magnetic resonance imaging was unremarkable in both patients, but analysis of cerebrospinal fluid (CSF) revealed chronic inflammation. KLHL11-IgG was positive in both patients (Patient 1 only in CSF, Patient 2 in serum). Neoplastic screening has so far not revealed any signs of active underlying malignancy. We found 15 publications of 112 patients in total with KLHL11-IgG encephalitis. Most patients (n = 82) had a cerebellar syndrome with or without signs of rhombencephalitis. The most common symptoms were ataxia (n = 82) and vertigo (n = 47), followed by oculomotor disturbances (n = 35) and hearing disorders (n = 31). Eighty of 84 patients had a GCT as an underlying tumor. CONCLUSIONS: Our cases demonstrate classical symptoms of KLHL11-IgG encephalitis. Early diagnosis and therapy are imperative. As with other PNSs, clinical awareness is needed and further studies are required especially in regard to therapeutic management.

Impact of sex in stroke in the young.

BACKGROUND AND PURPOSE: Limited data is available on sex differences in young stroke patients describing discrepant findings. This study aims to investigate the sex differences in young stroke patients. METHODS: Prospective cohort study comparing risk factors, etiology, stroke localization, severity on admission, management and outcome in patients aged 16-55 years with acute ischemic stroke consecutively included in the Bernese stroke database between 01/2015 to 12/2018 with subgroup analyses for very young (16-35y) and young patients (36-55y). RESULTS: 689 patients (39% female) were included. Stroke in women dominated in the very young (53.8%, p<0.001) and in men in the young (63.9%, p<0.001). As risk factors only sleep-disordered breathing was more predominant in men in the very young, whereas arterial hypertension, diabetes and atrial fibrillation did not differ in women and men older than 35y. The higher frequency of stroke in women in the very young may be explained by the sex specific risk factors such as pregnancy, puerperium, the use of oral contraceptives, and hormonal replacement therapy. Stroke severity at presentation, etiology, stroke localization, management, and outcome did not differ between women and men. CONCLUSIONS: The main finding of this study is that sex specific risk factors in women may contribute to a large extent to the higher incidence of stroke in the very young in women. Important modifiable stroke risk factors, such as arterial hypertension, diabetes mellitus and atrial fibrillation did not differ in women and men, either in the young as well as in the very young. These findings have major implications for primary preventive strategies of stroke in young people.

Multidimensional phenotyping of the post-COVID-19 syndrome: A Swiss survey study.

INTRODUCTION: Post-COVID-19 syndrome affects approximately 10-25% of people after a COVID-19 infection, irrespective of initial COVID-19 severity. The aim of this project was to assess the clinical characteristics, course, and prognosis of post-COVID-19 syndrome using a systematic multidimensional approach. PATIENTS AND METHODS: An online survey of people with suspected and confirmed COVID-19 and post-COVID-19 syndrome, distributed via Swiss COVID-19 support groups, social media, and our post-COVID-19 consultation, was performed. A total of 8 post-infectious domains were assessed with 120 questions. Data were collected from October 15 to December 12, 2021, and 309 participants were included. Analysis of clinical phenomenology of post-COVID-19 syndrome was performed using comparative statistics. RESULTS: The three most prevalent post-COVID-19 symptoms in our survey cohort were fatigue (288/309, 93.2%), pain including headache (218/309, 70.6%), and sleep-wake disturbances (mainly insomnia and excessive daytime sleepiness, 145/309, 46.9%). Post-COVID-19 syndrome had an impact on work ability, as more than half of the respondents (168/268, 62.7%) reported an inability to work, which lasted on average 26.6 weeks (95% CI 23.5-29.6, range 1-94, n = 168). Quality of life measured by WHO-5 Well-being Index was overall low in respondents with post-COVID-19 syndrome (mean, 95% CI 9.1 [8.5-9.8], range 1-25, n = 239). CONCLUSION: Fatigue, pain, and sleep-wake disturbances were the main symptoms of the post-COVID-19 syndrome in our cohort and had an impact on the quality of life and ability to work in a majority of patients. However, survey respondents reported a significant reduction in symptoms over 12 months. Post-COVID-19 syndrome remains a significant challenge. Further studies to characterize this syndrome and to explore therapeutic options are therefore urgently needed.