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Objectives: Limited evidence exists for the diagnostic performance of point-of-care tests for SARS-CoV-2 and influenza in community healthcare. We carried out a prospective diagnostic accuracy study of the LumiraDx™ SARS-CoV-2 and influenza A or B assay in primary care., Methods: Total of 913 adults and children with symptoms of current SARS-CoV-2 infection were recruited from 18 UK primary care practices during a period when Omicron was the predominant COVID variant of concern (June 2022 to December 2022). Trained health care staff performed the index test, with diagnostic accuracy parameters estimated for SARS-CoV-2 and influenza against real-time reverse-transcription PCR (rtRT-PCR)., Results: 151/887 participants were SARS-CoV-2 rtRT-PCR positive, 109 positive for Influenza A, 6 for Influenza B. Index test sensitivity for SARS-CoV-2 was 80.8% (122 of the 151, 95% CI, 73.6-86.7%) and specificity 98.9% (728 of the 736, 95% CI, 97.9-99.5%). For influenza A, sensitivity was 61.5% (67 of the 109, 95% CI, 51.7-70.6%) and specificity 99.4% (771 of the 776, 95% CI, 98.5-99.8%). Sensitivity to detect SARS-CoV-2 and influenza dropped sharply at rtRT-PCR cycle thresholds (Ct) > 30., Discussions: The LumiraDx™ SARS-CoV-2 and influenza A/B assay had moderate sensitivity for SARS-CoV-2 in symptomatic patients in primary care, with lower performance with high rtRT-PCR Ct. Negative results in this patient group cannot definitively rule out SARS-CoV-2 or influenza., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: To investigate the oscillatory activity in the Parkinsonian subthalamic nucleus using the macro-electrodes for deep brain stimulation., Methods: During bilateral deep brain stimulating electrode implantation, spontaneous and evoked field potentials were recorded from the subthalamic nucleus (STN) in two patients with Parkinson's disease (PD) during spontaneous resting tremor, passive manipulation of the wrist, and following electrical stimulation of the contralateral STN., Results: Frequency analysis of the STN field potentials recorded during spontaneous resting tremor showed significant coherence with electromyographic activity in the contralateral arm, suggesting a close involvement of the STN in the generation of resting tremor in PD. The STN responded to passive movement of the contralateral wrist, but not to ipsilateral movement. High frequency (100 Hz) electrical stimulation of the STN induced tremor (4 Hz) in both forearms, and also oscillation of the contralateral STN (4 Hz). In contrast, low frequency (5 Hz) stimulation induced contralateral arrhythmic involuntary movement (3 Hz), but without altering the contralateral STN activity., Conclusions: We propose that the functional connection between the STN and arm muscles is mainly contralateral, but cross talk may occur between bilateral STN via a frequency-dependent pathway.