Risks of neurological and psychiatric sequelae 2 years after hospitalisation or intensive care admission with COVID-19 compared to admissions for other causes.

The association between COVID-19 and subsequent neurological and psychiatric disorders is well established. However, two important questions remain unanswered. First, what are the risks in those admitted to intensive care unit (ICU) with COVID-19? Admission to ICU is itself associated with neurological and psychiatric sequelae and it is not clear whether COVID-19 further increases those risks or changes their profile. Second, what are the trajectories of neurological and psychiatric risks in patients admitted to hospital or ICU with COVID-19, and when do the risks subside? We sought to answer these two questions using a retrospective cohort study based on electronic health records (EHR) data from the TriNetX Analytics Network (covering 89 million patients, mostly in the USA). Cohorts of patients admitted to hospital or ICU with COVID-19 were propensity score-matched (for 82 covariates capturing risk factors for COVID-19 and more severe COVID-19 illness) to patients admitted to hospital or ICU (respectively) for any other reason. Matched cohorts were followed for up to two years and the risk of 14 neurological and psychiatric outcomes were compared. A total of 280,173 patients admitted to hospital and 46,573 patients admitted to ICU with COVID-19 were successfully matched to an equal number of patients admitted to hospital or ICU for any other reason. Those hospitalised with COVID-19 were found to be at a greater risk of a range of neurological and psychiatric outcomes including seizure/epilepsy, encephalitis, myoneural junction/muscle disease, Guillain-Barré syndrome (GBS), dementia, cognitive deficits, psychotic disorder, mood and anxiety disorders, but not ischaemic stroke or intracranial haemorrhage. When risks were elevated after COVID-19, most remained so for the whole two years of follow-up (except for mood and anxiety disorders). Risk profiles and trajectories were substantially different among those admitted to ICU: compared to those admitted for any other reasons, those admitted with COVID-19 were at a greater risk of myoneural junction/muscle disease, GBS, cognitive deficits and anxiety disorder, but at a significantly lower risk of ischaemic stroke, intracranial haemorrhage, encephalitis, and mood disorder. When elevated, the risks in those admitted to ICU with COVID-19 were mostly short-lived. In summary, risks of neurological and psychiatric sequelae in patients hospitalised with COVID-19 are wide ranging and long standing whereas those in patients admitted to ICU with COVID-19 are similar to, or lower than, the risks observed post-ICU admission for any other cause. These contrasting risk trajectories are relevant for researchers, clinicians, patients, and policymakers.

Ley H ，Skorniewska Z ，Harrison PJ ，Taquet M ... -  《-》

Neurological and psychiatric risk trajectories after SARS-CoV-2 infection: an analysis of 2-year retrospective cohort studies including 1 284 437 patients.

COVID-19 is associated with increased risks of neurological and psychiatric sequelae in the weeks and months thereafter. How long these risks remain, whether they affect children and adults similarly, and whether SARS-CoV-2 variants differ in their risk profiles remains unclear. In this analysis of 2-year retrospective cohort studies, we extracted data from the TriNetX electronic health records network, an international network of de-identified data from health-care records of approximately 89 million patients collected from hospital, primary care, and specialist providers (mostly from the USA, but also from Australia, the UK, Spain, Bulgaria, India, Malaysia, and Taiwan). A cohort of patients of any age with COVID-19 diagnosed between Jan 20, 2020, and April 13, 2022, was identified and propensity-score matched (1:1) to a contemporaneous cohort of patients with any other respiratory infection. Matching was done on the basis of demographic factors, risk factors for COVID-19 and severe COVID-19 illness, and vaccination status. Analyses were stratified by age group (age <18 years [children], 18-64 years [adults], and ≥65 years [older adults]) and date of diagnosis. We assessed the risks of 14 neurological and psychiatric diagnoses after SARS-CoV-2 infection and compared these risks with the matched comparator cohort. The 2-year risk trajectories were represented by time-varying hazard ratios (HRs) and summarised using the 6-month constant HRs (representing the risks in the earlier phase of follow-up, which have not yet been well characterised in children), the risk horizon for each outcome (ie, the time at which the HR returns to 1), and the time to equal incidence in the two cohorts. We also estimated how many people died after a neurological or psychiatric diagnosis during follow-up in each age group. Finally, we compared matched cohorts of patients diagnosed with COVID-19 directly before and after the emergence of the alpha (B.1.1.7), delta (B.1.617.2), and omicron (B.1.1.529) variants. We identified 1 487 712 patients with a recorded diagnosis of COVID-19 during the study period, of whom 1 284 437 (185 748 children, 856 588 adults, and 242 101 older adults; overall mean age 42·5 years [SD 21·9]; 741 806 [57·8%] were female and 542 192 [42·2%] were male) were adequately matched with an equal number of patients with another respiratory infection. The risk trajectories of outcomes after SARS-CoV-2 infection in the whole cohort differed substantially. While most outcomes had HRs significantly greater than 1 after 6 months (with the exception of encephalitis; Guillain-Barré syndrome; nerve, nerve root, and plexus disorder; and parkinsonism), their risk horizons and time to equal incidence varied greatly. Risks of the common psychiatric disorders returned to baseline after 1-2 months (mood disorders at 43 days, anxiety disorders at 58 days) and subsequently reached an equal overall incidence to the matched comparison group (mood disorders at 457 days, anxiety disorders at 417 days). By contrast, risks of cognitive deficit (known as brain fog), dementia, psychotic disorders, and epilepsy or seizures were still increased at the end of the 2-year follow-up period. Post-COVID-19 risk trajectories differed in children compared with adults: in the 6 months after SARS-CoV-2 infection, children were not at an increased risk of mood (HR 1·02 [95% CI 0·94-1·10) or anxiety (1·00 [0·94-1·06]) disorders, but did have an increased risk of cognitive deficit, insomnia, intracranial haemorrhage, ischaemic stroke, nerve, nerve root, and plexus disorders, psychotic disorders, and epilepsy or seizures (HRs ranging from 1·20 [1·09-1·33] to 2·16 [1·46-3·19]). Unlike adults, cognitive deficit in children had a finite risk horizon (75 days) and a finite time to equal incidence (491 days). A sizeable proportion of older adults who received a neurological or psychiatric diagnosis, in either cohort, subsequently died, especially those diagnosed with dementia or epilepsy or seizures. Risk profiles were similar just before versus just after the emergence of the alpha variant (n=47 675 in each cohort). Just after (vs just before) the emergence of the delta variant (n=44 835 in each cohort), increased risks of ischaemic stroke, epilepsy or seizures, cognitive deficit, insomnia, and anxiety disorders were observed, compounded by an increased death rate. With omicron (n=39 845 in each cohort), there was a lower death rate than just before emergence of the variant, but the risks of neurological and psychiatric outcomes remained similar. This analysis of 2-year retrospective cohort studies of individuals diagnosed with COVID-19 showed that the increased incidence of mood and anxiety disorders was transient, with no overall excess of these diagnoses compared with other respiratory infections. In contrast, the increased risk of psychotic disorder, cognitive deficit, dementia, and epilepsy or seizures persisted throughout. The differing trajectories suggest a different pathogenesis for these outcomes. Children have a more benign overall profile of psychiatric risk than do adults and older adults, but their sustained higher risk of some diagnoses is of concern. The fact that neurological and psychiatric outcomes were similar during the delta and omicron waves indicates that the burden on the health-care system might continue even with variants that are less severe in other respects. Our findings are relevant to understanding individual-level and population-level risks of neurological and psychiatric disorders after SARS-CoV-2 infection and can help inform our responses to them. National Institute for Health and Care Research Oxford Health Biomedical Research Centre, The Wolfson Foundation, and MQ Mental Health Research.

Taquet M ，Sillett R ，Zhu L ，Mendel J ，Camplisson I ，Dercon Q ，Harrison PJ ... -  《Lancet Psychiatry》

6-month neurological and psychiatric outcomes in 236 379 survivors of COVID-19: a retrospective cohort study using electronic health records.

Neurological and psychiatric sequelae of COVID-19 have been reported, but more data are needed to adequately assess the effects of COVID-19 on brain health. We aimed to provide robust estimates of incidence rates and relative risks of neurological and psychiatric diagnoses in patients in the 6 months following a COVID-19 diagnosis. For this retrospective cohort study and time-to-event analysis, we used data obtained from the TriNetX electronic health records network (with over 81 million patients). Our primary cohort comprised patients who had a COVID-19 diagnosis; one matched control cohort included patients diagnosed with influenza, and the other matched control cohort included patients diagnosed with any respiratory tract infection including influenza in the same period. Patients with a diagnosis of COVID-19 or a positive test for SARS-CoV-2 were excluded from the control cohorts. All cohorts included patients older than 10 years who had an index event on or after Jan 20, 2020, and who were still alive on Dec 13, 2020. We estimated the incidence of 14 neurological and psychiatric outcomes in the 6 months after a confirmed diagnosis of COVID-19: intracranial haemorrhage; ischaemic stroke; parkinsonism; Guillain-Barré syndrome; nerve, nerve root, and plexus disorders; myoneural junction and muscle disease; encephalitis; dementia; psychotic, mood, and anxiety disorders (grouped and separately); substance use disorder; and insomnia. Using a Cox model, we compared incidences with those in propensity score-matched cohorts of patients with influenza or other respiratory tract infections. We investigated how these estimates were affected by COVID-19 severity, as proxied by hospitalisation, intensive therapy unit (ITU) admission, and encephalopathy (delirium and related disorders). We assessed the robustness of the differences in outcomes between cohorts by repeating the analysis in different scenarios. To provide benchmarking for the incidence and risk of neurological and psychiatric sequelae, we compared our primary cohort with four cohorts of patients diagnosed in the same period with additional index events: skin infection, urolithiasis, fracture of a large bone, and pulmonary embolism. Among 236 379 patients diagnosed with COVID-19, the estimated incidence of a neurological or psychiatric diagnosis in the following 6 months was 33·62% (95% CI 33·17-34·07), with 12·84% (12·36-13·33) receiving their first such diagnosis. For patients who had been admitted to an ITU, the estimated incidence of a diagnosis was 46·42% (44·78-48·09) and for a first diagnosis was 25·79% (23·50-28·25). Regarding individual diagnoses of the study outcomes, the whole COVID-19 cohort had estimated incidences of 0·56% (0·50-0·63) for intracranial haemorrhage, 2·10% (1·97-2·23) for ischaemic stroke, 0·11% (0·08-0·14) for parkinsonism, 0·67% (0·59-0·75) for dementia, 17·39% (17·04-17·74) for anxiety disorder, and 1·40% (1·30-1·51) for psychotic disorder, among others. In the group with ITU admission, estimated incidences were 2·66% (2·24-3·16) for intracranial haemorrhage, 6·92% (6·17-7·76) for ischaemic stroke, 0·26% (0·15-0·45) for parkinsonism, 1·74% (1·31-2·30) for dementia, 19·15% (17·90-20·48) for anxiety disorder, and 2·77% (2·31-3·33) for psychotic disorder. Most diagnostic categories were more common in patients who had COVID-19 than in those who had influenza (hazard ratio [HR] 1·44, 95% CI 1·40-1·47, for any diagnosis; 1·78, 1·68-1·89, for any first diagnosis) and those who had other respiratory tract infections (1·16, 1·14-1·17, for any diagnosis; 1·32, 1·27-1·36, for any first diagnosis). As with incidences, HRs were higher in patients who had more severe COVID-19 (eg, those admitted to ITU compared with those who were not: 1·58, 1·50-1·67, for any diagnosis; 2·87, 2·45-3·35, for any first diagnosis). Results were robust to various sensitivity analyses and benchmarking against the four additional index health events. Our study provides evidence for substantial neurological and psychiatric morbidity in the 6 months after COVID-19 infection. Risks were greatest in, but not limited to, patients who had severe COVID-19. This information could help in service planning and identification of research priorities. Complementary study designs, including prospective cohorts, are needed to corroborate and explain these findings. National Institute for Health Research (NIHR) Oxford Health Biomedical Research Centre.

Taquet M ，Geddes JR ，Husain M ，Luciano S ，Harrison PJ ... -  《Lancet Psychiatry》

Six-month sequelae of post-vaccination SARS-CoV-2 infection: A retrospective cohort study of 10,024 breakthrough infections.

Vaccination has proven effective against infection with SARS-CoV-2, as well as death and hospitalisation following COVID-19 illness. However, little is known about the effect of vaccination on other acute and post-acute outcomes of COVID-19. Data were obtained from the TriNetX electronic health records network (over 81 million patients mostly in the USA). Using a retrospective cohort study and time-to-event analysis, we compared the incidences of COVID-19 outcomes between individuals who received a COVID-19 vaccine (approved for use in the USA) at least 2 weeks before SARS-CoV-2 infection and propensity score-matched individuals unvaccinated for COVID-19 but who had received an influenza vaccine. Outcomes were ICD-10 codes representing documented COVID-19 sequelae in the 6 months after a confirmed SARS-CoV-2 infection (recorded between January 1 and August 31, 2021, i.e. before the emergence of the Omicron variant). Associations with the number of vaccine doses (1 vs. 2) and age (<60 vs. ≥ 60 years-old) were assessed. Among 10,024 vaccinated individuals with SARS-CoV-2 infection, 9479 were matched to unvaccinated controls. Receiving at least one COVID-19 vaccine dose was associated with a significantly lower risk of respiratory failure, ICU admission, intubation/ventilation, hypoxaemia, oxygen requirement, hypercoagulopathy/venous thromboembolism, seizures, psychotic disorder, and hair loss (each as composite endpoints with death to account for competing risks; HR 0.70-0.83, Bonferroni-corrected p < 0.05), but not other outcomes, including long-COVID features, renal disease, mood, anxiety, and sleep disorders. Receiving 2 vaccine doses was associated with lower risks for most outcomes. Associations between prior vaccination and outcomes of SARS-CoV-2 infection were marked in those <60 years-old, whereas no robust associations were observed in those ≥60 years-old. In summary, COVID-19 vaccination is associated with lower risk of several, but not all, COVID-19 sequelae in those with breakthrough SARS-CoV-2 infection. The findings may inform service planning, contribute to forecasting public health impacts of vaccination programmes, and highlight the need to identify additional interventions for COVID-19 sequelae.

Taquet M ，Dercon Q ，Harrison PJ 《-》

Neurological Sequelae of COVID-19.

Though primarily a pulmonary disease, Coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 virus can generate devastating disease states that affect multiple organ systems including the central nervous system (CNS). The various neurological disorders associated with COVID-19 range in severity from mild symptoms such as headache, or myalgias to more severe symptoms such as stroke, psychosis, and anosmia. While some of the COVID-19 associated neurological complications are mild and reversible, a significant number of patients suffer from stroke. Studies have shown that COVID-19 infection triggers a wave of inflammatory cytokines that induce endothelial cell dysfunction and generate coagulopathy that increases the risk of stroke or thromboses. Inflammation of the endothelium following infection may also destabilize atherosclerotic plaque and induce thrombotic stroke. Although uncommon, there have also been reports of hemorrhagic stroke associated with COVID-19. The proposed mechanisms include a blood pressure increase caused by infection leading to a reduction in angiotensin converting enzyme-2 (ACE-2) levels that results in an imbalance of the renin-angiotensin system ultimately manifesting inflammation and vasoconstriction. Coagulopathy, as demonstrated by elevated prothrombin time (PT), has also been posited as a factor contributing to hemorrhagics stroke in patients with COVID-19. Other neurological conditions associated with COVID-19 include encephalopathy, anosmia, encephalitis, psychosis, brain fog, headache, depression, and anxiety. Though there are several hypotheses reported in the literature, a unifying pathophysiological mechanism of many of these disorders remains unclear. Pulmonary dysfunction leading to poor oxygenation of the brain may explain encephalopathy and other disorders in COVID-19 patients. Alternatively, a direct invasion of the CNS by the virus or breach of the blood-brain barrier by the systemic cytokines released during infection may be responsible for these conditions. Notwithstanding, the relationship between the inflammatory cytokine levels and conditions such as depression and anxiety is contradictory and perhaps the social isolation during the pandemic may in part be a contributing factor to some of the reported CNS disorders. In this article, we review the current literature pertaining to some of the most significant and common neurological disorders such as ischemic and hemorrhagic stroke, encephalopathy, encephalitis, brain fog, Long COVID, headache, Guillain-Barre syndrome, depression, anxiety, and sleep disorders in the setting of COVID-19. We summarize some of the most relevant literature to provide a better understanding of the mechanistic details regarding these disorders in order to help physicians monitor and treat patients for significant COVID-19 associated neurologic impairments. A literature review was carried out by the authors using PubMed with the search terms "COVID-19" and "Neurology", "Neurological Manifestations", "Neuropsychiatric Manifestations", "Stroke", "Encephalopathy", "Headache", "Guillain-Barre syndrome", "Depression", "Anxiety", "Encephalitis", "Seizure", "Spasm", and "ICUAW". Another search was carried out for "Long-COVID" and "Post-Acute COVID-19" and "Neurological Manifestations" or "Neuropsychiatric Manifestations". Articles such as case reports, case series, and cohort studies were included as references. No language restrictions were enforced. In the case of anxiety and depression, attempts were made to focus mainly on articles describing these conditions in infected patients. A total of 112 articles were reviewed. The incidence, clinical outcomes, and pathophysiology of selected neurological disorders are discussed below. Given the recent advent of this disease, the incidence of certain neurologic sequelae was not always available. Putative mechanisms for each condition in the setting of COVID-19 are outlined.

Ahmad SJ ，Feigen CM ，Vazquez JP ，Kobets AJ ，Altschul DJ ... -  《Journal of Integrative Neuroscience》