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Surgical Neurology International 2023Cerebral air embolism is a rare cause of acute ischemic stroke that is becoming increasingly well-described in the literature. However, the mechanism and severity of...
BACKGROUND
Cerebral air embolism is a rare cause of acute ischemic stroke that is becoming increasingly well-described in the literature. However, the mechanism and severity of this type of injury can vary, with ischemia typically emerging early in the course of care. To the best of our knowledge, delayed ischemia in this setting has not yet been described.
CASE DESCRIPTION
A stroke code was called for an unresponsive, hospitalized, 75-year-old man. A computerized tomography (CT) scan of the head revealed air within the right greater than left hemispheric cortical veins with loss of sulcation, concerning for developing ischemia, and CT angiography revealed absent opacification of the distal cortical vessels in the right anterior cerebral artery and middle cerebral artery territories. Magnetic resonance imaging (MRI) of the brain was obtained 5.75 h after the patient's last known well-showed small areas of subtle cortical diffusion restriction. Follow-up CT head within 24 h showed near-complete resolution of the air emboli after treatment with 100% fraction of inspired oxygen on mechanical ventilation. Subsequent MRI, performed 4 days after the initial event, showed extensive cortical diffusion restriction and cerebral edema crossing vascular territories.
CONCLUSION
This case highlights that cerebral air emboli can cause delayed ischemia that may not be appreciated on initial imaging. As such, affected patients may require intensive neurocritical care management, close neurologic monitoring, and repeat imaging irrespective of initial radiographic findings.
PubMed: 37680929
DOI: 10.25259/SNI_382_2023 -
Frontiers in Psychiatry 2023The prevalence of patent foramen ovale (PFO) is 15-35% among adults. The role of right-to-left shunting through the PFO, anxiety, depression, and hypoxemia in the...
The prevalence of patent foramen ovale (PFO) is 15-35% among adults. The role of right-to-left shunting through the PFO, anxiety, depression, and hypoxemia in the systemic circulation remains poorly understood. Herein, we present the case of a 52-year-old woman with no heart or lung disease, who was admitted due to anxiety for 5 months and had symptom exacerbation with dizziness for 4 days and presented with cyanosis. She was noted to have acute hypoxemia, with an oxygen saturation of 94.48% on room air, and arterial blood gas showed an oxygen tension of 65.64 mmHg. Agitated saline contrast echocardiography showed right-to-left shunting due to PFO. Arteriovenous fistula, pneumonia, pulmonary embolism, pulmonary hypertension, congestion peripheral cyanosis, ischemic peripheral cyanosis, and methemoglobin were excluded. Additionally, the patient improved by taking Paroxetine, Oxazepam, and Olanzapine. Her oxygen tension returned to 90.42 mmHg, and her symptoms resolved. In the case of severe anxiety and depression, right-to-left shunting through the PFO may cause acute systemic hypoxemia a flow-driven mechanism, occasionally manifesting as cyanosis. When anxiety improved, hypoxia also improved. Thus, the treatment of anxiety and depression seems effective in improving hypoxemia. Notably, this is a rare report, and we hope to draw the attention of psychosomatic specialists, psychiatrists, and clinicians to seek the relationship between anxiety appearing as acute stress and PFO. This may be a new therapeutic method for treating severe anxiety disorder.
PubMed: 37674554
DOI: 10.3389/fpsyt.2023.1229995 -
Clinical Neuroradiology Mar 2024Cerebral infarctions caused by air embolisms (AE) are a feared risk in endovascular procedures; however, the relevance and pathophysiology of these AEs is still largely...
PURPOSE
Cerebral infarctions caused by air embolisms (AE) are a feared risk in endovascular procedures; however, the relevance and pathophysiology of these AEs is still largely unclear. The objective of this study was to investigate the impact of the origin (aorta, carotid artery or right atrium) and number of air bubbles on cerebral infarctions in an experimental in vivo model.
METHODS
In 20 rats 1200 or 2000 highly calibrated micro air bubbles (MAB) with a size of 85 µm were injected at the aortic valve (group Ao), into the common carotid artery (group CA) or into the right atrium (group RA) using a microcatheter via a transfemoral access, resembling endovascular interventions in humans. Magnetic resonance imaging (MRI) using a 9.4T system was performed 1 h after MAB injection followed by finalization.
RESULTS
The number (5.5 vs. 5.5 median) and embolic patterns of infarctions did not significantly differ between groups Ao and CA. The number of infarctions were significantly higher comparing 2000 and 1200 injected MABs (6 vs. 4.5; p < 0.001). The infarctions were significantly larger for group CA (median infarction volume: 0.41 mm vs. 0.19 mm; p < 0.001). In group RA and in the control group no infarctions were detected. Histopathological analyses showed early signs of ischemic stroke.
CONCLUSION
Iatrogenic AEs originating at the ascending aorta cause a similar number and pattern of cerebral infarctions compared to those with origin at the carotid artery. These findings underline the relevance and potential risk of AE occurring during endovascular interventions at the aortic valve and ascending aorta.
Topics: Humans; Rats; Animals; Embolism, Air; Cerebral Infarction; Magnetic Resonance Imaging; Endovascular Procedures; Iatrogenic Disease
PubMed: 37665351
DOI: 10.1007/s00062-023-01347-2 -
Neurology India 2023The introduction of air into cerebral venous or arterial circulation known as cerebral air embolism (CAE) is a rare clinical entity. CAE is commonly iatrogenic secondary...
The introduction of air into cerebral venous or arterial circulation known as cerebral air embolism (CAE) is a rare clinical entity. CAE is commonly iatrogenic secondary to central venous catheter (CVC) placement or removal, various endoscopic procedures, or trauma or surgical scenarios. Here we report a case of spontaneous CAE in an unusual scenario. A 71-year-old male presented to emergency after developing giddiness following a yoga session. His MRI showed air embolism in the posterior fossa along cerebellar folia, prepontine, and suprasellar cisterns and tracking superiorly along the tentorium cerebelli. CAE is a rare clinical entity. Our case had CAE as a complication of cholesteatoma and possibly got triggered due to change in air pressor dynamics during yoga session.
Topics: Male; Humans; Aged; Embolism, Air; Endoscopy; Magnetic Resonance Imaging
PubMed: 37635514
DOI: 10.4103/0028-3886.383877 -
PloS One 2023Doppler ultrasound (DU) is used in decompression research to detect venous gas emboli in the precordium or subclavian vein, as a marker of decompression stress. This is...
Doppler ultrasound (DU) is used in decompression research to detect venous gas emboli in the precordium or subclavian vein, as a marker of decompression stress. This is of relevance to scuba divers, compressed air workers and astronauts to prevent decompression sickness (DCS) that can be caused by these bubbles upon or after a sudden reduction in ambient pressure. Doppler ultrasound data is graded by expert raters on the Kisman-Masurel or Spencer scales that are associated to DCS risk. Meta-analyses, as well as efforts to computer-automate DU grading, both necessitate access to large databases of well-curated and graded data. Leveraging previously collected data is especially important due to the difficulty of repeating large-scale extreme military pressure exposures that were conducted in the 70-90s in austere environments. Historically, DU data (Non-speech) were often captured on cassettes in one-channel audio with superimposed human speech describing the experiment (Speech). Digitizing and separating these audio files is currently a lengthy, manual task. In this paper, we develop a graphical user interface (GUI) to perform automatic speech recognition and aid in Non-speech and Speech separation. This constitutes the first study incorporating speech processing technology in the field of diving research. If successful, it has the potential to significantly accelerate the reuse of previously-acquired datasets. The recognition task incorporates the Google speech recognizer to detect the presence of human voice activity together with corresponding timestamps. The detected human speech is then separated from the audio Doppler ultrasound within the developed GUI. Several experiments were conducted on recently digitized audio Doppler recordings to corroborate the effectiveness of the developed GUI in recognition and separations tasks, and these are compared to manual labels for Speech timestamps. The following metrics are used to evaluate performance: the average absolute differences between the reference and detected Speech starting points, as well as the percentage of detected Speech over the total duration of the reference Speech. Results have shown the efficacy of the developed GUI in Speech/Non-speech component separation.
Topics: Humans; Diving; Decompression Sickness; Embolism, Air; Ultrasonography, Doppler; Subclavian Vein
PubMed: 37561745
DOI: 10.1371/journal.pone.0283953 -
CASE (Philadelphia, Pa.) Jul 2023• Myocardial enhancement after agitated saline contrast study in a dog is described. • Suspect air microemboli can inadvertently be introduced into coronary...
• Myocardial enhancement after agitated saline contrast study in a dog is described. • Suspect air microemboli can inadvertently be introduced into coronary vasculature. • Air microemboli are a theoretic risk of saline contrast echocardiography.
PubMed: 37546359
DOI: 10.1016/j.case.2023.02.009 -
PloS One 2023Fish exposed to water supersaturated with dissolved gas experience gas embolism similar to decompression sickness (DCS), known as gas bubble disease (GBD) in fish. GBD...
Fish exposed to water supersaturated with dissolved gas experience gas embolism similar to decompression sickness (DCS), known as gas bubble disease (GBD) in fish. GBD has been postulated as an alternative to traditional mammals' models on DCS. Gas embolism can cause mechanical and biochemical damage, generating pathophysiological responses. Increased expression of biomarkers of cell damage such as the heat shock protein (HSP) family, endothelin 1 (ET-1) or intercellular adhesion molecule 1 (ICAM-1) has been observed, being a possible target for further studies of gas embolism. The GBD model consisted of exposing fish to supersaturation in water with approximately 170% total dissolved gas (TDG) for 18 hours, producing severe gas embolism. This diagnosis was confirmed by a complete histopathological exam and the gas score method. HSP70 showed a statistically significant upregulation compared to the control in all the studied organs (p <0.02). Gills and heart showed upregulation of HSP90 with statistical significance (p = 0.015 and p = 0.02, respectively). In addition, HSP70 gene expression in gills was positively correlated with gas score (p = 0.033). These results suggest that gas embolism modify the expression of different biomarkers, with HSP70 being shown as a strong marker of this process. Furthermore, gas score is a useful tool to study the abundance of gas bubbles, although individual variability always remains present. These results support the validity of the GBD model in fish to study gas embolism in diseases such as DCS.
Topics: Animals; Embolism, Air; Fishes; Water; HSP70 Heat-Shock Proteins; Gene Expression; Decompression Sickness; Mammals
PubMed: 37440588
DOI: 10.1371/journal.pone.0288659