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COVID-19

Neurological Complications of COVID-19

This article will be reviewing the impact COVID-19 has on the functioning of the human nervous system and current up to date case studies regarding this topic. The information from this article was gathered using PubMed which is a search engine that gives access to the biomedical database, MEDLINE.

COVID-19 Background

COVID-19, also known as Severe Acute Respiratory Syndrome Coronavirus Two (SARS-CoV-2 for short), is an infectious respiratory illness that is the cause of the “COVID-19 Pandemic”. The first case of this respiratory illness was reported in late December 2019 in Wuhan, China. From December 2019 to present day, there has been a rapid increase in cases with the United States being a contender for the most cases at a total of more than seven million cases and approximately 210,000 deaths. Worldwide, there are a total of almost thirty-eight million cases with about one million deaths. 

Neurological Complications

COVID-19 impacts the neurological functioning of many people diagnosed with this illness and causes detrimental effects to the nervous system. This is leading to a rise in mortality in the ceaseless COVID-19 pandemic. Currently, there are many efforts being made in research to uncover many of the neurological complications in patients affected by COVID-19. These complications include headache, dizziness, myalgia, loss of smell and taste, with more serious complications including the worsening of strokes and seizures. It remains uncertain where the development of these complications occur, although it seems that these complications are typically prevalent in older patients with pre-existing risk factors which include Type two diabetes, cancer, chronic kidney disease, sickle cell disease, coronary artery disease, etc. Neurological functioning is being impacted by COVID-19 mainly due to hypoxic-ischemic injury to the brain. In other words, COVID-19 is causing a lack of oxygen in the brain because of low oxygen levels in the blood.

Figure 1: SARS-CoV-2 invasion of the CNS and symptoms of the direct invasion. 

CNS = central nervous system; BBB = blood-brain barrier

There have also been reports of brain inflammation as one of the neurological complications of COVID-19. Many of the people who went through the symptoms of having brain inflammation also experienced a rare disorder which is called acute demyelinating encephalomyelitis (ADEM). ADEM is triggered by the viral infections of the SARS-CoV-2 which leads to damage of the myelin sheaths that surround the nerves in the brain. This disturbs the homeostasis of the brain and causes death of the neurons. 

In order for the brain to remain at the optimal level of homeostasis, the autonomic nervous system and its related limbs have to function properly.  Another neurological disorder that is the result of COVID-19 is Guillain-Barré syndrome. Guillain-Barré syndrome is a rare neurological disorder in which the immune system attacks healthy nerves in the body. This disorder is also involved in the damage of the myelin sheath. Overall, the main neurological complications of COVID-19 include seizures, brain inflammation (ADEM), anosmia, hypoxia, Guillain-Barré syndrome (very rare), and stroke being a primary concern for many doctors and researchers. 

Case Studies

According to the medical article, “Neuroinvasion, neurotropic, and neuroinflammatory events of SARS-CoV-2: understanding the neurological manifestations in COVID-19 patients”, the authors included a clinical study of seven hundred sixty-five COVID-19 patients. In a clinical study of seven hundred sixty-five COVID-19 patients, about 18% of the patients had neurological complications such as acute myelitis and Guillain-Barré syndrome. Clinical studies have also shown that the loss of the sense of smell is turning out to be one of the most common symptoms in patients diagnosed with COVID-19, indicating that olfactory dysfunction is a prognostic factor. Another article, “Neurological manifestations of COVID-19 and other coronaviruses: A systematic review” discusses seven case studies that were done in patients diagnosed with a positive coronavirus test result. The investigation had concluded that encephalitis was a prevalent disorder in the pediatric age range. The case study investigation had four hundred nine patients, who were diagnosed with COVID-19, had an onset of neurological complications such as headaches, dizziness, epileptic seizures, neuralgia, and only about 1.4 percent of the patients had the Guillain-Barré syndrome. 

Conclusion

The coronavirus pandemic has caused a lot of tension throughout the world with a death toll of more than one million people and a drastic total of more than thirty-eight million cases. Doctors and scientists have found that some patients diagnosed with a positive coronavirus results also have an onset of neurological complications. Although many of the neurological complications aren’t life-threatening, about ten to 20 percent of the complications are requiring hospitalizations and are fatal. Such complications include brain inflammation, acute cerebrovascular diseases, meningitis, hypoxic encephalopathy and the most rare of all the complications which is Guillain-Barré syndrome. There have been many case studies done to highlight that some of the more crucial disorders are very rare with having only about one percent of the patients in a case study be diagnosed with a rare complication. These neurological complications raise concerns and questions regarding how much worse the complications could get if and when the virus strain gets more stronger, crushing the world with a possible second wave. The only way to find out is testing patients and analyzing case studies to find answers to the questions and concerns on the rise about COVID-19. 

Samiksha Komatireddy, Youth Medical Journal 2020

References

[1] Iadecola, C., Anrather, J., & Kamel, H. (2020). Effects of COVID-19 on the nervous system. Cell, 183(1), 16-27.e1. https://pubmed.ncbi.nlm.nih.gov/32882182/

[2] Stafstrom, C. E., & Jantzie, L. L. (2020). COVID-19: Neurological considerations in neonates and children. Children (Basel, Switzerland), 7(9). doi:10.3390/children7090133

https://pubmed.ncbi.nlm.nih.gov/32927628/

[3] Orsini, A., Corsi, M., Santangelo, A., Riva, A., Peroni, D., Foiadelli, T., … Striano, P. (2020). Challenges and management of neurological and psychiatric manifestations in SARS-CoV-2 (COVID-19) patients. Neurological Sciences: Official Journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology, 41(9), 2353–2366.

https://pubmed.ncbi.nlm.nih.gov/32767055/

[4] Bostanciklioglu, M. (2020). Severe acute respiratory syndrome coronavirus 2 is penetrating to dementia research. Current Neurovascular Research, 17. doi: 10.2174/1567202617666200522220509 

https://pubmed.ncbi.nlm.nih.gov/32442082/

[5] Özdağ Acarli, A. N., Samanci, B., Ekizoğlu, E., Çakar, A., Şirin, N. G., Gündüz, T., … Baykan, B. (2020). Coronavirus disease 2019 (COVID-19) from the Point of View of neurologists: Observation of neurological findings and symptoms during the combat against a pandemic. Noro Psikiyatri Arsivi, 57(2), 154–159. 

https://pubmed.ncbi.nlm.nih.gov/32550783/

[6] Correia, A. O., Feitosa, P. W. G., Moreira, J. L. de S., Nogueira, S. Á. R., Fonseca, R. B., & Nobre, M. E. P. (2020). Neurological manifestations of COVID-19 and other coronaviruses: A systematic review. Neurology, Psychiatry, and Brain Research, 37, 27–32.

https://pubmed.ncbi.nlm.nih.gov/32834527/

[7] Yachou, Y., El Idrissi, A., Belapasov, V., & Ait Benali, S. (2020). Neuroinvasion, neurotropic, and neuroinflammatory events of SARS-CoV-2: understanding the neurological manifestations in COVID-19 patients. Neurological Sciences: Official Journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology, 41(10), 2657–2669.

https://pubmed.ncbi.nlm.nih.gov/32725449/

[8] Baig, A. M., & Sanders, E. C. (2020). Potential neuroinvasive pathways of SARS-CoV-2: Deciphering the spectrum of neurological deficit seen in coronavirus disease-2019 (COVID-19). Journal of Medical Virology, (jmv.26105). doi:10.1002/jmv.26105

https://pubmed.ncbi.nlm.nih.gov/32492193/

By Samiksha Komatireddy

Samiksha Komatireddy is a first year undergraduate student majoring in biochemistry on the pre-med track. She is interested in pursuing a career in the medical field, specifically in neurosurgery. She has been interning as a research intern of neurological surgery and health affairs at the University of California, Irvine Medical Center from 2017-present. Samiksha is also an active COVID-19 contact tracer and care navigator for LA county testing sites in Redondo Beach, California.

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