Rare Neurological Disorders Linked to COVID-19
Mon, April 19, 2021

Rare Neurological Disorders Linked to COVID-19



Since the COVID-19 pandemic began, several cases of autoimmune and autoinflammatory diseases have been reported in several parts of the world. Health experts already expected that such cases will emerge because the coronavirus disease is highly contagious and can severely impact a person’s immune system. 

Kawasaki disease, for instance, was first reported in Europe. According to several reports, more than a dozen children in hospitals have had high fevers, abdominal pain, skin rashes, and markers of severe inflammation in their blood. Some of these children tested positive for COVID-19 while those who tested negative carried antibodies specific to the virus in their blood, suggesting they had already recovered from the infection. 

The National Organization for Rare Disorders (NORD) reported that Kawasaki disease is a childhood illness that triggers inflammation in the blood vessels and can cause lasting heart damage. One study from Italy noted a "30-fold increased incidence of Kawasaki-like disease" between mid-February and April, which led many health professionals to think that it is linked to COVID-19. 

Recently, reports have shown rare autoimmune disorders linked to COVID-19: the Guillain-Barré syndrome and acute disseminated encephalomyelitis (ADEM).




About the Guillain-Barré Syndrome

According to Healthline, an American website and provider of health information, Guillain-Barré syndrome affects about 1 in 100,000 Americans. While there’s no cure for this, treatment can reduce the severity of a person’s symptoms and shorten the duration of the illness.

As COVID-19 continues to spread across the world, more and more researchers are conducting studies to understand why some infected patients are developing neurological complications such as Guillain-Barré syndrome. This disorder is known to emerge from bacterial infections and a multitude of viral infections, including the flu virus, Zika virus, and other coronaviruses. 

Campylobacter, for instance, is one of the most common bacterial causes of diarrhea in the US and the most common risk factor for Guillain-Barré. Neurologists usually perform a detailed neurological exam to determine whether or not a person has the disorder. It occurs when the body's own immune system attacks and injures the nerves outside of the spinal cord or brain. When diagnosed with Guillain-Barré, patients will find it difficult to respond to the signals they receive from their brains because their nerves are already damaged.

There are several symptoms of Guillain-Barré syndrome. Usually, a person would feel a tingling sensation in their toes, feet, and legs, which spreads upward to their arms and fingers. They could also suffer from muscle weakness, difficulty walking steadily, severe lower back pain, paralysis, difficulty breathing, fast heart rate, loss of bladder control, and difficulty in moving their eyes or face, talking, chewing, or swallowing.

Cases of Guillain-Barré syndrome were first reported in Italy, Spain, and China, where the COVID-19 pandemic surged before the US crisis. This is also not the first time this disorder has been linked to a viral infection. According to Science Alert, a leading scientific publisher dedicated to publishing peer-reviewed significant research work, delivering quality content, previous studies have shown an increase in Guillain-Barré Syndrome cases following the 2009 H1N1 flu pandemic.

As of July, there have been 10 reported cases of COVID-19 patients with Guillain-Barré syndrome—five in Italy, two in Iran, two in the US, and one from Wuhan, China. Unfortunately, it’s hard for patients to go through diagnostic tests such as a nerve conduction study due to the pandemic and infection-containment considerations. The reported cases were diagnosed based on clinical examination by neurological experts rather than any tests.

According to the Global Consortium Study of Neurological Dysfunctions in COVID-19, researchers are studying how often neurological problems like Guillain-Barré syndrome is seen in hospitalized COVID-19 patients. Health experts also clarified that being diagnosed with this disorder doesn’t mean it was caused by the virus.





About the Acute Disseminated Encephalomyelitis

Another condition linked to COVID-19 is acute disseminated encephalomyelitis (ADEM), a rare brain inflammation that is usually triggered by viral infections. It affects a person’s brain and spinal cord and is typically seen in children. Researchers from the University of College London warned clinicians to be aware of possible neurological effects to make an early diagnosis and improve patient outcomes.

A recent study published in the journal Brain revealed that ADEM appears to be increasing in prevalence due to the pandemic. According to Medical Xpress, a web-based medical and health news service that features the most comprehensive coverage in the fields of neuroscience, cardiology, and more, the researchers provided a detailed account of neurological symptoms experienced by 43 people who had either confirmed or suspected COVID-19.

Author Dr. Rachel Brown from the UCL Queen Square Institute of Neurology and UCL Infection and Immunity said that this research can help in understanding the different ways in which COVID-19 can affect the brain. "Our study amalgamates, for the first time, the clinical presentations of patients with Covid-19 neurological disease with MRI and laboratory features including, in one case, a brain biopsy,” senior author Dr. Hadi Manji said.

The team studied 12 cases of brain inflammation, 10 cases of transient encephalopathies with delirium, eight cases of strokes, and eight others with nerve damage, mainly Guillain-Barré syndrome. They found out that 9 out of 12 cased of those with brain inflammation conditions were diagnosed with ADEM. While further studies are still needed, researchers said that the increase of ADEM cases to at least one per week is concerning.

“Given that the disease has only been around for a matter of months, we might not yet know what long-term damage Covid-19 can cause. Doctors need to be aware of possible neurological effects, as early diagnosis can improve patient outcomes. People recovering from the virus should seek professional health advice if they experience neurological symptoms," author Dr. Ross Paterson from UCL Queen Square Institute of Neurology said.

Senior author Dr. Michael Zandi from the UCL Queen Square Institute of Neurology and University College London Hospitals NHS Foundation Trust also said that they have identified a higher than expected number of people with neurological conditions such as brain inflammation. They found a link between COVID-19 and several neurological complications such as delirium, stroke, and nerve damage.

"We should be vigilant and look out for these complications in people who have had Covid-19. Whether we will see an epidemic on a large scale of brain damage linked to the pandemic—perhaps similar to the encephalitis lethargica outbreak in the 1920s and 1930s after the 1918 influenza pandemic—remains to be seen,” Zandi said.