ABSTRACT
OBJECTIVE: Systemic hypoxia occurs in COVID-19 infection; however, it is unknown if cerebral hypoxia occurs in convalescent individuals. We have evidence from other conditions associated with central nervous system inflammation that hypoxia may occur in the brain. If so, hypoxia could reduce the quality of life and brain function. This study was undertaken to assess if brain hypoxia occurs in individuals after recovery from acute COVID-19 infection and if this hypoxia is associated with neurocognitive impairment and reduced quality of life. METHODS: Using frequency-domain near-infrared spectroscopy (fdNIRS), we measured cerebral tissue oxygen saturation (StO2) (a measure of hypoxia) in participants who had contracted COVID-19 at least 8 weeks prior to the study visit and healthy controls. We also conducted neuropsychological assessments and health-related quality of life assessments, fatigue, and depression. RESULTS: Fifty-six percent of the post-COVID-19 participants self-reported having persistent symptoms (from a list of 18), with the most reported symptom being fatigue and brain fog. There was a gradation in the decrease of oxyhemoglobin between controls, and normoxic and hypoxic post-COVID-19 groups (31.7 ± 8.3 µM, 27.8 ± 7.0 µM and 21.1 ± 7.2 µM, respectively, p = 0.028, p = 0.005, and p = 0.081). We detected that 24% of convalescent individuals' post-COVID-19 infection had reduced StO2 in the brain and that this relates to reduced neurological function and quality of life. INTERPRETATION: We believe that the hypoxia reported here will have health consequences for these individuals, and this is reflected in the correlation of hypoxia with greater symptomology. With the fdNIRS technology, combined with neuropsychological assessment, we may be able to identify individuals at risk of hypoxia-related symptomology and target individuals that are likely to respond to treatments aimed at improving cerebral oxygenation.
Subject(s)
COVID-19 , Hypoxia, Brain , Humans , Oxygen , Quality of Life , COVID-19/complications , Hypoxia, Brain/complications , Hypoxia, Brain/diagnostic imaging , Hypoxia , Brain/diagnostic imagingABSTRACT
This chapter focuses on the direct and observable effects of COVID-19 on Central Nervous System (CNS) structures and functions. It includes a review of the persistent symptoms caused by CNS damage during the acute infection by the viral infection, the immune/inflammatory response, and brain hypoxia. Viruses or bacteria can directly infect cells within the brain or spinal cord, infect the membranes surrounding the brain, or by establishing abscesses within the brain. There is strong evidence that COVID-19 causes several forms of long-term brain disease. Nasal obstruction during upper respiratory infections, when the nasal passages are substantially blocked, by seasonal allergies, or as a result of COVID-19, can also cause a temporary loss of smell. Strokes that increased during acute COVID-19 were primarily related to the hypercoagulable state of blood and an inflammatory effect on brain blood vessels that interfered with normal brain oxygenation. © 2023 John Wiley & Sons Ltd. All rights reserved.
ABSTRACT
In December 2019, the novel coronavirus strain SARS-CoV-2 caused an outbreak that quickly spread worldwide and led to the COVID-19 pandemic. COVID-19, the severe infectious disease caused by SARS-CoV-2, often presents with symptoms including fever, cough, and mental confusion and can cause the acute respiratory inflammatory disorder. Additionally, viral infection with SARS-CoV-2 is associated with mental health, neuronal degeneration, and psychiatric complications. With infection by the virus, cytokines are released by immune cells, causing acute systemic inflammation affecting the lungs. Lung damage can occur, resulting in hypoxia, brain damage, and mental health dysfunction. In addition, a cascade of inflammatory cytokines, including IL-1, IL-6, and TNF, are released, a phenomenon termed the "cytokine storm" that causes serious pathological damage to tissues and organs and mental health. This exaggerated production of cytokines leads to lymphopenia and disrupts the balance of Treg and Th17 cells, weakening the immune system. The elderly population is particularly at risk for damage associated with the "cytokine storm", which can affect neurological functions or result in death. Copyright © by BIOLIFE.
ABSTRACT
In December 2019, the novel coronavirus strain SARS-CoV-2 caused an outbreak that quickly spread worldwide and led to the COVID-19 pandemic. COVID-19, the severe infectious disease caused by SARS-CoV-2, often presents with symptoms including fever, cough, and mental confusion and can cause the acute respiratory inflammatory disorder. Additionally, viral infection with SARS-CoV-2 is associated with mental health, neuronal degeneration, and psychiatric complications. With infection by the virus, cytokines are released by immune cells, causing acute systemic inflammation affecting the lungs. Lung damage can occur, resulting in hypoxia, brain damage, and mental health dysfunction. In addition, a cascade of inflammatory cytokines, including IL-1, IL-6, and TNF, are released, a phenomenon termed the "cytokine storm" that causes serious pathological damage to tissues and organs and mental health. This exaggerated production of cytokines leads to lymphopenia and disrupts the balance of Treg and Th17 cells, weakening the immune system. The elderly population is particularly at risk for damage associated with the "cytokine storm", which can affect neurological functions or result in death. Copyright © by BIOLIFE.
ABSTRACT
Case Diagnosis: Acute Necrotizing Hemorrhagic Encephalopathy Secondary to COVID-19 Infection Case Description or Program Description: A 51-year-old previously healthy male had a hospitalization complicated by respiratory failure requiring intubation, acute renal failure, and sepsis due to COVID-19 pneumonia. His persistent encephalopathy and MRI showing cerebellar microhemorrhages were consistent with acute necrotizing hemorrhagic encephalopathy (ANHE) secondary to COVID-19 infection. He was transferred to acute inpatient rehabilitation after being weaned off his ventilator. Upon admission, the patient was unable to ambulate and required maximum assistance with bed mobility and dressing. His physical exam demonstrated 4/5 left upper extremity strength, 4/5 right lower extremity strength, 2/5 strength left hip flexion, and 1/5 strength left ankle dorsiflexion. Right knee flexion was limited to 5 degrees. Setting(s): Acute Rehabilitation Hospital Assessment/Results: The patient underwent 58 days of multidisciplinary inpatient rehabilitation. His respiratory status and dysphagia improved significantly. He was decannulated from his tracheostomy tube and had his percutaneous endoscopic gastrostomy tube removed. He was able to ambulate independently, climb stairs with supervision, and became independent with all activities of daily living. He was discharged home after 155 days of hospitalization. Discussion (relevance): ANHE is a rare and disabling neurologic manifestation of COVID-19. Its pathophysiology is poorly understood, but hypothesized to be due to intracranial cytokine storm and/or brain hypoxia. Characteristic imaging features symmetric, multifocal lesions that appear hypoattentuating on head CT. T2/FLAIR MRI shows hyperintense signals with internal hemorrhage. To our knowledge, the role of rehabilitation in recovery from ANHE has not been previously described. Our patient was admitted to acute inpatient rehabilitation requiring maximum assistance for most activities of daily living. Despite his severe debility, he was able to transition home, requiring minimal assistance from his family. Conclusion(s): It is important to consider ANHE as a neurological complication in patients with severe COVID-19 infection. Furthermore, physicians should recognize the role of rehabilitation in patient recovery.
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CASE: A 44 year old female with history of depression and recent suicide attempt presents with one week of cognitive and functional decline. One month prior to presentation, patient attempted suicide with opioids requiring intubation for respiratory depression and stroke sequelae. She was discharged from this stay after 12 days having returned to mental and functional baseline. Two weeks later, she demonstrated decreased focus and concentration, progressing to decreased mobility and akinesis, eventually presenting to our hospital. Admission metabolic and toxic workup was negative. CT head redemonstrated findings of previously known stroke. MRI demonstrated new increased T2 Flair of the parietal lobes and the cerebral white matter. LP was without evidence of infection or inflammation. Encephalitis panel and autoimmune workup were negative. Neurology consult suggested delayed post-hypoxic leukoencephalopathy as a possible diagnosis, given clinical course of improvement and subsequent decline, along with akinetic mutism and deep cortical white matter flair abnormalities. After failed trial of lorazepam, she was started on amantadine and her cognitive and functional status improved slowly. IMPACT/DISCUSSION: Delayed post-hypoxic leukoencephalopathy (DPHL) is a rare syndrome characterized by biphasic time course with initial recovery and subsequent cognitive and functional decline. DPHL can follow any event of prolonged cerebral hypoxia most frequently CO poisoning. It can occur with more common causes of hypoxia including overdose, cardiac arrest, and seizures;recent case reports have reported DPHL following severe covid infection. The clinical course involves a hypoxic event followed by a return to functional baseline typically lasting 7-21 days, after which progressive physical and mental decline occur. Signs include neuropsychiatric symptoms like amnesia and disorientation, as well as parkinsonism or akinetic mutism (1). The mechanism of DPHL is unclear. One possible mechanisms involves diffuse demyelination. The half life of myelin basic proteins is approximately 20 days, the length of the lucid interval. Hypoxia may abruptly halt the myelination process but symptoms may not emerge until a critical threshold of loss was achieved. Evaluation of DPHL involves considering other causes of encephalopathy, such as infection, substance use, stroke, catatonia, and toxins. In the absence of other causes, diagnosis of DPHL is based on characteristic time course following hypoxic event, symptoms, and MRI findings of diffuse T2 hyperintensity of cerebral white matter are pathognomonic (1). Treatment of DPHL is generally supportive. Limited evidence suggests amantadine may be of benefit. CONCLUSION: Physicians should consider DPHL in patients who have experienced cerebral hypoxia and present with the characteristic time course and imaging findings.
ABSTRACT
Most SARS CoV-2 infections probably occur unnoticed or cause only cause a mild common cold that does not require medical intervention. A significant proportion of more severe cases is characterized by early neurological symptoms such as headache, fatigue, and impaired consciousness, including respiratory distress. These symptoms suggest hypoxia, specifically affecting the brain. The condition is best explained by primary replication of the virus in the nasal respiratory and/or the olfactory epithelia, followed by an invasion of the virus into the central nervous system, including the respiratory centers, either along a transneural route, through disruption of the blood-brain barrier, or both. In patients, presenting with early dyspnea, the primary goal of therapy should be the reversal of brain hypoxia as efficiently as possible. The first approach should be intermittent treatment with 100% oxygen using a tight oronasal mask or a hood. If this does not help within a few hours, an enclosure is needed to increase the ambient pressure. This management approach is well established in the hypoxia-related diseases in diving and aerospace medicine and preserves the patient's spontaneous breathing. Preliminary research evidence indicates that even a small elevation of the ambient pressure might be lifesaving. Other neurological symptoms, presenting particularly in long COVID-19, suggest imbalance of the autonomous nervous system, i.e., dysautonomia. These patients could benefit from vagal nerve stimulation.
ABSTRACT
Background: Neurological manifestations are a major complication of sudden acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and likely contribute to symptoms of "long COVID". Elucidating the mechanisms that underlie neuropathogenesis in infection is critical for identifying or developing viable therapeutic strategies. While neurological injury in infection is varied, cerebrovascular disease is seen at a high frequency among patients over 50 years of age. Additionally, microhemorrhages and hypoxic-ischemic injury are often described in brain autopsy series of human subjects who died from COVID-19. Here, we report neuropathology in aged SARS-CoV-2 infected non-human primates (NHPs) is consistent with that observed in aged human subjects and provide insight into the underlying cause. Methods: Four adult Rhesus macaques and four African green monkeys were inoculated with the 2019-nCoV/USA-WA1/2020strain of SARS-CoV-2 via a multi-route mucosal or aerosol challenge. Two of each species were included as age-matched controls. Frontal, parietal, occipital, and temporal lobes, basal ganglia, cerebellum, and brainstem were interrogated through histopathological and immunohistochemical techniques to identify and characterize the observed pathology. Results: Like humans, pathology was variable but included wide-spread inflammation with nodular lesions, neuronal injury, and microhemorrhages. Neuronal degeneration and apoptosis were confirmed with FluoroJade C and cleaved caspase 3 IHC, which showed foci of positivity, particularly among cerebellar Purkinje cells. This was seen even among infected animals that did not develop severe respiratory disease but was not seen in age-matched controls. Significant upregulation of the alpha subunit of hypoxia inducible factor 1 (HIF1-α), indicative of tissue hypoxia, was observed in brain of all infected animals, regardless of disease severity. Sparse virus was detected in brain endothelial cells but did not associate with the severity of CNS injury. Conclusion: SARS-CoV-2 infected NHPs are a viable animal model for advancing our current understanding of infection-associated neuropathogenesis. Upregulation of HIF1-α in brain of infected animals suggests cerebral hypoxia may underlie or contribute to neuroinflammation and neuronal injury/death and may provide some insight into neurological manifestations observed among asymptomatic patients or those only suffering mild disease.
ABSTRACT
The Centers for Disease Control and Prevention identified the first case of the novel coronavirus disease 2019 (COVID-19) on January 21, 2020 in the United States. Since its arrival, the virus has caused widespread havoc on the nation as a whole as well as on all individuals. The coronavirus family is not new to the field of medicine. In fact, the viral pathogenicity dates back to the early 1960s, with more information on the respiratory preference and the ability to cause acute respiratory pathology coming later in 2002. The novel coronavirus, severe acute respiratory syndrome coronavirus 2, causes a disease commonly referred to as COVID-19, which has a well documented course of severe respiratory pathology along with interesting systemic consequences that often complicate the clinical picture. This case presents an otherwise healthy young 35-year-old male who contracted the novel coronavirus, leading to multi-organ hypoxia and triggering a syncopal episode which resulted in physical trauma to the head leading to a minor subarachnoid hemorrhage.