Although initially viewed as a flu-like respiratory infection, over the past 6 months we've come to appreciate that SARS-COV-2 can cause a wide spectrum of disease (see Nature Med. Review: Extrapulmonary manifestations of COVID-19) across many other organ systems.
While the case fatality rate of COVID-19 - with appropriate medical care - appears to hover somewhere around 1%, we continue to see reports of severe and protracted illness, slow recoveries (see Months after infection, many COVID-19 patients can't shake illness), and in many cases, significant sequelae.
Two weeks ago, the Pan American Health Organization (PAHO) - in a 16-page Epidemiological Alert on Complications and sequelae of COVID-19 - acknowledged the growing evidence that many people who `recover' from a SARS-CoV-2 infection do so with lasting damage.
Much of the concern has been focused on the impact of SARS-COV-2 infection on the heart, and in June JAMA published an original investigation which found a 3-fold increase in out-of-hospital cardiac arrests in New York City during the peak of their COVID-19 epidemic, finding:
From March 1 to April 25, 2020, New York City, New York (NYC), reported 17 118 COVID-19–related deaths. On April 6, 2020, out-of-hospital cardiac arrests peaked at 305 cases, nearly a 10-fold increase from the prior year.
Other studies have linked cardiac arrhythmias and heart muscle inflammation to COVID-19, including:
JAMA: Two Studies Linking SARS-CoV-2 Infection To Cardiac Injury
EID Journal: Relative Bradycardia In Mild To Moderate COVID-19 Cases, Japan
The Cardiovascular Impact of COVID-19
Some cardiologists have even warned that the impact of COVID-19 on cardiovascular health may not be fully revealed for years to come (see Coronavirus Disease 2019 (COVID-19) and the Heart—Is Heart Failure the Next Chapter? by Clyde W. Yancy, MD, MSc1,; Gregg C. Fonarow, MD).
Neurological manifestations ranged from relatively mild (headaches, dizziness, anosmia, mild confusion, etc.) to more profound (seizures, stupor, loss of consciousness, etc.) to potentially fatal (ischemic stroke, cerebral hemorrhage, muscle injury (rhabdomyolysis), etc.).
Of note, in this study neurological symptoms were detected in 30.2% of non-severe cases, and nearly half (45.5%) of severe cases. While some of these lingering effects may eventually resolve, for many survivors, long-term impairment is a real possibility.
The Lancet: COVID-19: Can We Learn From Encephalitis Lethargica?
In light of these reports, the question is increasingly being asked: Are we facing a crashing wave of neuropsychiatric sequelae of COVID-19? Neuropsychiatric symptoms and potential immunologic mechanisms by Emily A. Troyer, Jordan N. Kohn, and Suzi Hong.
All of which brings us to a new review, this time from the Journal of Neurology, which discusses the potential long-term impact of COVID-19 in causing chronic neurological disorders in some of its survivors. Disorders that may take months or even years to become apparent.
While admittedly speculative, these concerns are not without some basis in fact (and history).
Increasingly, we've seen Parkinson’s disease tentatively linked to viral infections (see Viral Parkinsonism by Haeman Jang, David A. Boltz, Robert G. Webster, and Richard Jay Smeyne), and more recently, in 2017's Nature Comms: Revisiting The Influenza-Parkinson's Link.
Whether due to a neurotropic pathogen, or the body's inflammatory immune response, viral and bacterial infection (i.e. West Nile Virus, EV-D68, Campylobacter jejuni, etc) have been strongly linked to CNS disorders like AFM (Acute Flaccid Paralysis) and Guillain-Barré syndrome (GBS).
All of which brings us to the following review. Follow the link to read it in its entirety.
Published: 27 August 2020
COVID-19: dealing with a potential risk factor for chronic neurological disorders
Tommaso Schirinzi, Doriana Landi & Claudio Liguori
AbstractSARS-CoV2 infection is responsible for a complex clinical syndrome, named Coronavirus Disease 2019 (COVID-19), whose main consequences are severe pneumonia and acute respiratory distress syndrome. Occurrence of acute and subacute neurological manifestations (encephalitis, stroke, headache, seizures, Guillain–Barrè syndrome) is increasingly reported in patients with COVID-19.
Moreover, SARS-CoV2 immunopathology and tissue colonization in the gut and the central nervous system, and the systemic inflammatory response during COVID-19 may potentially trigger chronic autoimmune and neurodegenerative disorders.
Specifically, Parkinson’s disease, multiple sclerosis and narcolepsy present several pathogenic mechanisms that can be hypothetically initiated by SARS-CoV2 infection in susceptible individuals. In this short narrative review, we summarize the clinical evidence supporting the rationale for investigating SARS-CoV2 infection as risk factor for these neurological disorders, and suggest the opportunity to perform in the future SARS-CoV2 serology when diagnosing these disorders.