Lingering symptoms and health outcomes in recovered coronavirus disease 2019 (COVID-19) patients are increasingly being reported. Some individuals experience a host of persistent symptoms – from chronic fatigue, to breathing difficulty, to ‘brain fog’ – several months after their bout of the disease.
However, there is currently a lack of data on the neurological and psychiatric outcomes of patients who have recovered from COVID-19.
To address this, researchers at the University of Oxford and the Oxford University Hospitals NHS Foundation Trust in the United Kingdom have aimed to determine the prevalence of patients who experience neurological and psychiatric conditions six months after recovering from COVID-19.
The team estimated the incidence of International Classification of Diseases 10 (ICD-10) diagnoses in the six months after being diagnosed with COVID-19. Among these conditions included intracranial hemorrhage, ischemic stroke, Guillain-Barre’ syndrome, Parkinsonism, nerve root disorders, muscle disease, dementia, encephalitis, anxiety, psychotic disorders, substance misuse, and insomnia.
The researchers have published their findings on the pre-print medRxiv* server.
Persistent COVID-19 symptoms and outcomes
The increasing number of recovered COVID-19 patients exhibiting neurological and psychiatric sequelae months after infection highlights the need for further research and follow-up among convalescents.
COVID-19 ‘long-haulers’ have been described as those patients who have recovered from the infection, but experience persistent symptoms months after the onset of their symptoms. Previous studies also explored the incidence of recovered patients who were at an increased risk of neurological disorders.
These studies based utilized findings from other coronaviruses and were followed by case series. There have been similar concerns about psychiatric sequelae of COVID-19. Evidence showed that survivors were at a heightened risk of mood and anxiety disorders, as well as dementia, in the three months after being infected with SARS-CoV-2.
The researchers used retrospective cohort studies and time-to-event analysis to estimate the incidence of ICD-10 diagnoses in the six months after COVID-19 detection.
The researchers obtained data from the TriNetX electronic health records network, which contains more than 81 million patients. They compared the incidences with patients with influenza or other respiratory infections using a Cox model.
The team also analyzed whether being hospitalized and encephalopathy during acute COVID-19 affect these risks.
Findings of the study showed that 236,379 patients recovered from COVID-19. Among these, the approximate incidence of neurological or psychiatric sequelae at six months was 33.6 percent. About 12.8 percent of these patients received their first diagnosis of these conditions.
Further, the team found that most of the diagnoses were more common after COVID-19 than after having flu or other respiratory infections, including stroke, intracranial hemorrhage, psychotic disorders, and dementia.
The team also revealed that COVID-19 who were hospitalized and those who had encephalopathy were more likely to develop neurological and psychiatric conditions.
Potential mechanisms for this association include viral invasion of the central nervous system, hypercoagulable states, and neural effects of the immune response. On the other hand, it is also notable that incidence of these diagnoses was increased even in the COVID-19 cases who had not required hospitalization,” the researchers explained.
The study utilized a large sample size, though it acknowledges that electronic health records may have unknown completeness, including sparse information on lifestyle and socioeconomic factors and a lack of validation of diagnoses.
Nevertheless, the study highlighted the potential scale of post-viral neurological and psychiatric sequelae. Further study is needed to strengthen the validity of the findings.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.