As the COVID-19 pandemic sweeps across the globe, many neurologic specialists have been on the lookout for potentially serious nervous system complications such as Guillain-Barre syndrome.
Though Guillain-Barre syndrome is rare, it is well known to emerge following bacterial infections, such as Campylobacter jejuni, a common cause of food poisoning, and a multitude of viral infections including the flu virus, Zika virus and other coronaviruses.
Studies showed an increase in Guillain-Barre syndrome cases following the 2009 H1N1 flu pandemic, suggesting a possible connection. The presumed cause for this link is that the body’s own immune response to fight the infection turns on itself and attacks the peripheral nerves.
This is called an ‘autoimmune’ condition. When a pandemic affects as many people as the current COVID-19 crisis, even a rare complication can become a significant public health problem. That is especially true for one that causes neurological dysfunction where the recovery takes a long time and may be incomplete.
The first reports of Guillain-Barre syndrome in COVID-19 can lead to Guillain-Barre syndrome, many important questions remain. What are the chances that someone gets Gullain-Barre syndrome during or following a COVID-19 infection? Does Guillain-Barre syndrome happen more often in those who have been infected with COVID-19 compared to other types of infections, such as the flu?
The only way to get answers is through a prospective study where the doctors perform systematic surveillance and collect data on a large group of patients. There are ongoing large research consortia hard at work to figure out answers to these questions.
Understanding the association between COVID-19 and Guillain-Barre syndrome
While large research studies are underway, overall it appears that Guillain-Barre syndrome is a rare but serious phenomenon possibly linked to COVID-19. Given that more than 10.7 million* cases have been reported for COVID-19, there have been 10** reported cases of COVID-19 patients with Guillain-Barre syndrome so far.
It is certainly possible that there are other cases that have not been reported. The Global Consortium Study of Neurological Dysfunctions in COVID-19 is actively underway to find out how often neurological problems like Guillain-Barre syndrome is seen in hospitalized COVID-19 patients.
Also, just because Guillain-Barre syndrome occurs in a patient diagnosed with COVID-19, that does not imply that it was caused by the virus; this still may be a coincident occurrence. More research is needed to understand how the two events are related.
Due to the pandemic and infection-containment considerations, diagnostic tests, such as a nerve conduction study that used to be routine for patients with suspected Guillain-Barre syndrome, are more difficult to do. In both U.S. cases, the initial diagnosis and treatment were all based on clinical examination by neurological experts rather than any tests. Both patients survived but with significant residual weakness at the time these case reports came out, but that is not uncommon for Guillain-barre syndrome patients. Though the reported cases of Guillain-Barre syndrome so far all have severe symptoms, this is not uncommon in a pandemic situation where the less sick patients may stay at home and not present for medical care for fear of being exposed to the virus. This may skew our current detection of Guillain-Barre syndrome cases toward the sicker patients who have to go to a hospital.
*10.7 million cases worldwide as of 2nd July 2020
** The Lancet reported 19 cases of GBS July 2020