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Background Methacholine challenge tests (MCTs) are used to diagnose airway hyperresponsiveness (AHR) in patients with suspected asthma where previous diagnostic testing has been inconclusive. The test is time consuming and usually requires referral to specialized centers. Simple methods to predict AHR could help determine which patients should be referred to MCTs, thus avoiding unnecessary testing. Here we investigated the potential use of baseline spirometry variables as surrogate markers for AHR in adults with suspected asthma. Methods Baseline spirometry and MCTs performed between 2013 and 2019 in a large tertiary center were retrospectively evaluated. Receiver-operating characteristic curves for the maximal expiratory flow-volume curve indices (angle β, FEV1, FVC, FEV1/FVC, FEF50%, FEF25–75%) were constructed to assess their overall accuracy in predicting AHR and optimal cutoff values were identified. Results A total of 2983 tests were analyzed in adults aged 18–40 years. In total, 14% of all MCTs were positive (PC20 ≤ 16 mg/ml). All baseline spirometry parameters were significantly lower in the positive group (p 50% showed the best overall accuracy (AUC = 0.688) and proved to be useful as a negative predictor when applying FEF50% ≥ 110% as a cutoff level. Conclusions This study highlights the role of FEF50% in predicting AHR in patients with suspected asthma. A value of ≥ 110% for baseline FEF50% could be used to exclude AHR and would lead to a substantial decrease in MCT referrals.

Background Paraneoplastic neurological syndromes (PNS) are a group of syndromes that affect the central and peripheral neuromuscular system in association with cancer. Specific antibodies may assist in the diagnosis of PNS. The antibodies tested can be classified into those directed against intracellular neuronal proteins (“well characterized” PNS: Hu, Yo, RI, CV2, amphiphysin, Ma1, Ma2) and those directed against neural surface antigens (autoimmune encephalitis syndromes: NMDA, AMPA, LGI1, CASPR2, GABAR). We aimed to characterize patients with unexplained neuropsychiatric symptoms, in whom positive PNS antibodies were detected in the Sheba medical center, a large referral hospital. Methods Clinical and demographic data of patients with positive PNS antibodies were collected during the years 2002–2016. Antibodies were tested by either Line immunoassay or by cell-based indirect immunofluorscent assay. Results During the follow up of 14 years, 4010 PNS tests were performed in patients with unexplained neuropsychiatric symptoms. Seventy-two were found to be positive; among them we had full clinical data access to 44. The most frequent antibodies were anti-Hu (31.8%), anti-Yo (18.2%), anti-CV2 (13.6%), and anti-NMDA (9.1%), and the most common cancers were small-cell lung (SCLC) and ovarian cancers. In the well characterized paraneoplastic group, cancer was diagnosed in 55.9% of the patients, and in the autoimmune encephalitis group, 40.0% were diagnosed with cancer. A positive correlation between antibody titer and the presence of cancer was found. Ninety percent of the tests in patients who were found positive were ordered by a neurologist or neuro-oncologist. Conclusions The titers of PNS auto-antibodies can predict cancer in patients whom anti-PNS antibodies are tested. In addition, consultation with a specialist should be considered before this test is ordered.

Summary Background & aims Despite the thorough mapping of brain pathways involved in eating behavior, no treatment aimed at modulating eating dysregulation from its neurocognitive root has been established yet. We aimed to evaluate the effect of N.I.R. H.E.G. (Near Infra-Red Hemoencephalography) neurofeedback training on appetite control, weight and food-related brain activity. Methods Six healthy male participants with overweight or mild obesity went through 10 N.I.R. H.E.G. neurofeedback sessions designed to practice voluntary activation of the prefrontal cortex. Weight, eating behavior, appetite control and brain activity related to food and self-inhibition based on fMRI were evaluated before and after neurofeedback training. Results Our study group demonstrated a positive trend of increased self-control and inhibition related to food behavior, reduced weight and increased activation during an fMRI response-inhibition task (Go-No-Go – GNG) in the predefined region of interest (ROI): superior orbitofrontal cortex (sOFC). Conclusions N.I.R. H.E.G. holds a promising potential as a feasible neurofeedback platform for modulation of cortical brain circuits involved in self-control and eating behavior and should be further evaluated and developed as a brain modifying device for the treatment and prevention of obesity.