Autonomic neuroscience : basic & clinical
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As global numbers of COVID-19 grow, chronic neurological symptoms, including those of autonomic dysfunction, are being reported with increasing frequency. Mounting evidence suggests that many patients experience chronic and sometimes debilitating symptoms long after their acute infectious period, leading to the new diagnostic category of post-acute COVID syndrome. Many symptoms of post-acute COVID syndrome appear autonomic in nature, suggesting that autonomic impairment may play a central role in the underlying pathophysiology. In this review, we discuss the autonomic symptoms and manifestations of post-acute COVID syndrome, potential mechanisms involved, and future directions for a better understanding of this novel condition.
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Opioids produce pupillary constriction but their impact on pupillary unrest and the dynamic parameters of the pupillary light reflex have not been characterized. Given the increasing use of portable pupillometers for care of critically ill patients, it is important to distinguish between opioid effects on the pupil versus those that have been reported to arise from traumatic and ischemic brain insults. We undertook this study to determine which pupillary responses are most profoundly and consistently affected by a progressive infusion of remifentanil. ⋯ PUAL is a highly specific indicator of central opioid effect. As a non-invasive measure, it may provide useful data to clinicians who prescribe opioids.
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The heart receives parasympathetic and to a lesser degree sympathetic input via the vagus nerve. Here, we investigated whether morphological changes of the cervical vagus nerves (VN) as assessed by high-resolution ultrasound (HRUS) correlated with the autonomic cardiac innervation. ⋯ We also found an inverse correlation between the left VN-CSA and HRV as well as parasympathetic parameters. The results imply an asymmetric parasympathetic (vagal) innervation of the heart.
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Postural Orthostatic Tachycardia Syndrome is most commonly seen in women of child bearing age, however little is known about its effects in pregnancy. ⋯ Postural Orthostatic Tachycardia Syndrome should not be a contraindication to pregnancy. Symptom course is variable during pregnancy and the post-partum period. Continuing pre-conception medication may help symptoms, with no significant risks reported. Obstetric complications, not Postural Orthostatic Tachycardia Syndrome, should dictate mode of delivery. Postural Orthostatic Tachycardia Syndrome did not appear to affect the rate of adverse events. These results are important in determining appropriate management and care in this population.
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Augmentation of cardiac sympathetic tone has been shown to induce ventricular arrhythmias. Acupuncture has been clinically used to treat hypertension, angina pectoris, and atrial arrhythmias. However, the effects of acupuncture on ventricular electrophysiology and autonomic tone remain unknown. ⋯ EA significantly attenuated the increase in LF/HF (EA 0.6 ± 0.1 vs. control 1.1 ± 0.2, P < 0.05). In conclusion, EA reduces the cardiac excitability induced by LSS through correction of cardiac sympathovagal balance. This study provides mechanistic insights underlying cardiac neuromodulation of EA during sympathoexcitation.