As of now, over 4.7 million people have been infected with the novel coronavirus and around 315,000 deaths have been reported all across the globe. In the U.S. alone, the number of COVID-19 cases has risen to a staggering 1.48 million. The state of New Jersey is one of the two states with the highest infection rate in the country; the other one is New York. Around 146,000 cases have so far been reported in New Jersey and over 10,000 people have lost their lives to the deadly virus.
It is a well-known fact that the novel coronavirus, SARS-CoV-2, results in respiratory illness, presenting in a vast majority of cases with fever, body aches, a feeling of being ill, fatigue, cough, sore throat, and in some cases, difficulty in breathing. These are the symptoms that are most commonly associated with most viral respiratory infections. However, as the number of cases continues to rise throughout the world, more and more information is being obtained regarding the effects of this virus on the human body. It is now understood that, in addition to the respiratory system, the coronavirus can also infect other organ systems of the body, including the heart, gastrointestinal system, and the nervous system. Neurological involvement is of particular significance and is now being increasingly reported in COVID-19 patients.
Commonly reported neurological features
Mao and colleagues conducted a retrospective chart review of a total of 214 patients hospitalized for the management of laboratory-confirmed COVID-19 in Wuhan, China. This is, perhaps, the only study that provides the most comprehensive picture of the neurological manifestations of the disease at this point in time. According to the results of this study, neurological symptoms were observed in 36% of the patients who had a mild COVID-19 infection; whereas, around 45% of patients with severe COVID-19 infection had neurologic manifestations. The patients with severe COVID-19 illness were older and had more underlying diseases, particularly high blood pressure. The breakdown of the neurological manifestations reported by this study is as follows:
- Central nervous system (CNS) symptoms – The central nervous system comprises of the brain and spinal cord. The researchers observed that out of 36% of patients with neurological symptoms, the central nervous system was affected in 24.8%. The most commonly reported CNS symptoms were dizziness (16.8%), headache (13.1%), decreased level of consciousness (7.5%), and stroke (2.8%).
- Peripheral nervous system (PNS) symptoms – 9% of the patients had symptoms related to the peripheral nervous system, which comprises of the nerves present outside the brain and spinal cord. Loss of taste (5.6%) and loss of smell (5.1%) were the two most commonly reported peripheral nervous system manifestations.
- Skeletal muscle injury – Muscle injury was another common manifestation observed in this study, and10.7% of the patients were found to have skeletal muscle injury symptoms.
Even higher rates of neurological manifestations were reported in a group of 64 patients who were hospitalized for the management of COVID-19-induced acute respiratory distress syndrome (ARDS) in Strasbourg, France. According to a letter published in the New England Journal of Medicine, neurological symptoms, including significant agitation, confusion, and alterations in the contraction of muscles, were noted to be present in 58 out of the 64 patients.
Several case reports have also been published that describe certain unusual neurological manifestations in individuals with COVID-19. A few of these are mentioned here:
- Acute hemorrhagic necrotizing encephalopathy – On March 31, 2020, the first presumptive case of a rare central nervous system disorder associated with COVID-19 was reported in Detroit, Michigan. The patient was a 58-year-old woman who was an airline worker and presented with fever, cough, and disorientation for three days. She tested positive for COVID-19 and was later diagnosed to have acute hemorrhagic necrotizing encephalopathy, a rare brain disorder that may occur as a complication of influenza or other viral infections, and may lead to significant disability and even death.
- Encephalitis – Encephalitis refers to the development of inflammation and swelling of the brain tissue. Encephalitis may be associated with certain viral infections, such as herpes simplex, and has now also been reported as an unusual neurological manifestation of COVID-19.
- Guillain-Barré syndrome – It is a disorder of the peripheral nervous system that may be triggered by a bacterial or viral infection. The immune system mistakenly attacks the body’s own peripheral nerve cells while responding to the infection. Muscle weakness and tingling sensations in the lower extremities may be the initial symptoms, followed by paralysis that spreads from the lower extremities to the upper half of the body. The first presumptive case of Guillain-Barré syndrome linked to COVID-19 was reported in China. This was followed by a report of five patients in northern Italy who developed Guillain-Barré syndrome after the onset of COVID-19.
Neurological problems were also reported to occur with the severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS) viruses. The precise mechanism involved in the development of COVID-19 associated neurological symptoms is not yet understood. However, it is hypothesized that the SARS-CoV-2 virus may be attacking the brain just like the SARS and MERS viruses did. Moreover, patients with severe COVID-19 infection and central nervous system manifestations have been found to have low levels of lymphocytes, white blood cells that help the body fight against infection. This suggests that the virus may make the body more vulnerable to illness by weakening the immune system.
The already reported neurologic findings have provided valuable clinical insight and have prompted the clinicians to look for certain signs and symptoms, such as headache, dizziness, muscle weakness, or other nervous system problems, in COVID-19 patients. However, the neurological manifestations associated with COVID-19 are yet to be studied in detail and there is still much to learn about the novel coronavirus. Precise documentation, detailed clinical assessment and investigations, and future large-scale epidemiological studies are required to understand the pathogenic mechanisms involved in the development of these neurological symptoms and to discover effective interventions for the treatment of these complications.
- Cases in the U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/cases-in-us.html. Published May 18, 2020. Accessed May 18, 2020.
- Mao L, Jin H, Wang M, et al. Neurologic Manifestations of Hospitalized Patients With Coronavirus Disease 2019 in Wuhan, China. JAMA Neurol. Published online April 10, 2020. doi:10.1001/jamaneurol.2020.1127
- Neurologic Features in Severe SARS-CoV-2 Infection: NEJM. New England Journal of Medicine. https://www.nejm.org/doi/full/10.1056/NEJMc2008597. Published on April 15, 2020. Accessed May 18, 2020.
- Poyiadji N, Shahin G, Noujaim D, Stone M, Patel S, Griffith B. COVID-19–associated Acute Hemorrhagic Necrotizing Encephalopathy: CT and MRI Features. Radiology. https://pubs.rsna.org/doi/10.1148/radiol.2020201187. Published March 31, 2020. Accessed May 18, 2020.
- Ye M, Ren Y, Lv T. Encephalitis as a clinical manifestation of COVID-19 [published online ahead of print, 2020 Apr 10]. Brain Behav Immun. 2020;S0889-1591(20)30465-7. doi:10.1016/j.bbi.2020.04.017
- Zhao H, Shen D, Zhou H, Liu J, Chen S. Guillain-Barré syndrome associated with SARS-CoV-2 infection: causality or coincidence?https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(20)30109-5/fulltext. The Lancet Neurology. 2020; 19 (5) , pp. 383-384.
- Guillain–Barré Syndrome Associated with SARS-CoV-2: NEJM. New England Journal of Medicine. https://www.nejm.org/doi/full/10.1056/NEJMc2009191. Published on April 17, 2020. Accessed May 18, 2020.