Outpatient management of Post-COVID syndrome - single center experience.

BACKGROUND: COVID patients continue to experience unremitting symptoms that extend far beyond the initial illness. While there is rapid accumulation of data on acute COVID treatment in hospitalized patients, little is known regarding post-COVID management. OBJECTIVES: To describe our center's experience treating post-COVID sub-syndromes encountered in Post-COVID Lung Clinic. METHODS: We retrospectively reviewed data on 98 post-COVID patients evaluated in our clinic between 07/01/2020-12/31/2022. We encountered three distinct post-COVID subtypes: 1) respiratory complaints associated with increased O2 requirements and abnormal CT findings (post-COVID interstitial lung disease [ILD]), 2) respiratory complaints associated with tachycardia (post-COVID dyspnea-tachycardia syndrome [DTS]). Post-COVID ILD patients (n = 28) received steroids in combination with cell cycle inhibitor (mycophenolate mofetil-MMF). Post-COVID DTS patients (n = 16) were treated with metoprolol. 3) A third, undifferentiated group presented with mild respiratory complaints and normal spirometry (n = 17) and was followed in clinic without initiation of a specific treatment. RESULTS: In treated post-COVID ILD patients, mean oxygen requirements at rest (1.96 ± 1.79 L/NC) decreased to 0.89 ± 1.29 L/NC at 6 months follow-up, p = 0.005. In patients with post-COVID DTS, mean heart rate at rest decreased (98 ± 15 bpm to 79 ± 11 bpm) at 6 months follow-up, p = 0.023. 60 % of patients reported an improvement in exertional dyspnea. CONCLUSIONS: Our descriptive study presents a single center outpatient COVID-19 clinic experience. We encountered 3 post-COVID sub-syndromes and describe their treatments: post-COVID interstitial lung disease [ILD] treated with a novel regimen of MMF and steroids, post COVID dyspnea-tachycardia syndrome [DTS] treated with metoprolol, and a third subgroup with mild undifferentiated symptoms without specific treatment.

Norepinephrine and serotonin are required for vagus nerve stimulation directed cortical plasticity.

Vagus nerve stimulation (VNS) paired with forelimb training drives robust, specific reorganization of movement representations in the motor cortex. This effect is hypothesized to be mediated by VNS-dependent engagement of neuromodulatory networks. VNS influences activity in the locus coeruleus (LC) and dorsal raphe nucleus (DRN), but the involvement of these neuromodulatory networks in VNS-directed plasticity is unknown. We tested the hypothesis that cortical norepinephrine and serotonin are required for VNS-dependent enhancement of motor cortex plasticity. Rats were trained on a lever pressing task emphasizing proximal forelimb use. Once proficient, all rats received a surgically implanted vagus nerve cuff and cortical injections of either immunotoxins to deplete serotonin or norepinephrine, or vehicle control. Following surgical recovery, rats received half second bursts of 0.8 mA or sham VNS after successful trials. After five days of pairing intracortical microstimulation (ICMS) was performed in the motor cortex contralateral to the trained limb. VNS paired with training more than doubled cortical representations of proximal forelimb movements. Depletion of either cortical norepinephrine or serotonin prevented this effect. The requirement of multiple neuromodulators is consistent with earlier studies showing that these neuromodulators regulate synaptic plasticity in a complimentary fashion.