The coronavirus not only causes respiratory problems – neurological symptoms up to severe strokes also accumulate. A neurologist explains possible consequences.
Infection with the SARS-CoV-2 coronavirus can damage all organs: lungs, heart, kidneys – and also the brain. Professor Dr. Peter Berlit, General Secretary of the German Society for Neurology (DGN), explains in an interview with t-online.de what has been known about brain damage and which neurological disorders are most common among Covid 19 patients.
Berlit also warns that the number of strokes could increase because patients neglect prevention due to the corona pandemic. Even now, significantly fewer patients with minor strokes would come to the clinics.
t-online.de: Professor Dr. Berlit, what is known about possible damage to the brain, spinal cord and nerves from the coronavirus?
Professor Dr. Peter Berlit: The answer to this question is not easy. We know that all areas of the nervous system – i.e. the brain, spinal cord and peripheral nerves – can be affected by the coronavirus. The question is: is this a direct effect of the viral infection that leads to the damage or – that seems to be the case for the most part – is it an indirect effect of the corona virus infection? In the brain, we most often see diffuse damage in intensive care patients, which can lead to confusion, memory problems, hallucinations, epileptic seizures and other symptoms. Magnetic resonance imaging shows damage to the so-called white matter in the brain with small punctiform hemorrhages. On the one hand, the lack of oxygen plays a role in severe pneumonia. On the other hand, an excessive immune response to the virus can lead to brain damage. Both the brain and the spinal cord can also be damaged by encephalomyelitis – an inflammatory disease of the central nervous system – as we know from multiple sclerosis. This damage is probably immunological.
What other neurological diseases have been identified?
In rare cases, inflammation of the brain and meninges (meningoencephalitis) has been diagnosed in Covid-19 patients. The corona virus could be detected in the nerve water. In intensive care patients, the peripheral nerves – i.e. nerves that lie outside the brain and spinal cord and run through the entire body – can also be damaged. This is often related to the ventilation and the severe course of the patient’s illness. Finally, the so-called Guillain-Barré syndrome can also occur as a result of the virus infection via an increased immune response. This inflammatory disease of the peripheral nerves in turn leads to paralysis and also breathing problems. Typically, the syndrome occurs five to ten days after the lung infection. This means that the patient first goes through the lung infection, and after it has subsided, ascending paralysis occurs. Here too, an increased immune response to the virus is assumed to be the cause.
(Source: Jens Komossa, Berlin)
Prof. Dr. Peter Berlit is a neurologist and general secretary of the German Society for Neurology (DGN).
What are the most common neurological disorders in Covid 19 patients?
The most common neurological symptoms that occur with Covid-19 are olfactory and taste disorders. The virus causes infection of the upper respiratory tract and the olfactory nerve tract ends exactly in the upper area of the nose. The previous findings suggest that the coronavirus SARS-CoV-2 can damage the olfactory nerve and can also reach the brain via the olfactory nerve. Smell and taste disorders have been reported in up to 80 percent of European patients.
How long can smell and taste disorders last?
In over 90 percent, the symptoms resolve within four to five weeks. What happens to the remaining ten percent is still unclear. However, we know that the disorders can last for a few months. It is not yet possible to answer whether they can also lead to permanent damage. With influenza – the normal one Influenza – it is the case that the malodour disorders can regress up to a year after the infection. We won’t be able to say until spring 2021 how often there will be a permanent loss of smell and taste with Covid-19.
Brain scan: Recent studies and case reports increasingly describe effects of Covid-19 on the brain. (Source: digicomphoto / Getty Images)
Can neurological symptoms indicate a corona infection before respiratory problems occur?
Yes that is unfortunately so. This applies especially to the smell and taste disorders. These can be the first symptoms of corona infection. The interesting thing about it: With flu, it is usually the case that when the patients can no longer smell and taste, they usually have a stuffy nose. But with Covid-19 the nasal breathing is free and nevertheless those affected can no longer smell and taste. If such symptoms occur, Covid-19 testing is urgently required. Unfortunately, there are also first case reports that a stroke can also appear as the first symptom of a Covid 19 infection.
Why can healthy people also have a stroke with a corona infection?
Reports from the US and Europe show that strokes can also occur in young healthy people. Upregulation of the coagulation system is assumed to be the trigger. Because with Covid-19 there is a massive increase in thrombosis tendency. Many patients experience thrombosis in the leg veins, pulmonary embolism can occur – and regardless of this, strokes.
Are you finding out that the corona pandemic is affecting care for stroke patients?
There have been several examinations in the USA and we are also observing it with concern in European countries such as Italy, Spain and Germany: Significantly fewer patients with minor strokes come to the clinics and are there on stroke units – departments specializing in stroke patients in the hospital – treat. We fear that this will have an indirect impact of the pandemic because people are afraid of getting infected in the hospital and therefore do not take stroke warning symptoms as seriously as they should. Every second stroke there are volatile symptoms, also known as transient ischemic attack (TIA) or mild stroke. And these precede severe strokes. At the moment we cannot really assess the impact of the pandemic, but we fear that severe strokes will end up being more common than before. And not just because of the virus, but mainly because those affected do not go to the clinic if there are warning signs.
The Transient ischemic attack – in short TIA – is considered a harbinger of a stroke. It starts suddenly and causes the same symptoms as a stroke.
Are symptoms like inflammation of the brain known from other infectious diseases?
Yes, in the previous coronavirus epidemics it was also the case that both pathogens – SARS a little more than MERS – showed neurotropy. This means that they can attack the nervous system and also manifest there. We know this from other viruses too. The most common causative agent for brain inflammation is the herpes simplex virus. It is known to cause lip sores. Chickenpox or shingles can also cause brain inflammation.
Are there special rehab programs for Covid-19 patients with neurological complications?
In Germany there are special neuro-rehabilitation programs that specifically treat damage that occurs neurologically as a result of a corona infection. Neuropsychological therapies are particularly important. Because Covid-19-Patients often have memory, concentration and attention problems. However, there are no special rehabilitation clinics that only care for Covid 19 patients.
Thank you for the interview!