An infection with the coronavirus Sars-CoV-2 can not only manifest itself with fever, cough and difficulty breathing but can also cause neurological symptoms. This is the result of a study by Chinese scientists with patients in Wuhan, the epicenter of the pandemic, from which the virus spread worldwide. As the doctors report in the journal “JAMA Neurology”, a good third of the 214 patients they examined showed signs that the virus had damaged the nervous system. The most common symptoms included dizziness and headache, as well as olfactory and taste disorders.
Reports of corona patients losing their sense of smell and taste, at least temporarily, had accumulated in the past few days. These symptoms indicated that the brain was involved, said Bernd Salzberger from the Regensburg University Hospital. “So far, however, there have been very few examinations of the brain of corona patients. We are still in the dark.”
The current study from Wuhan is also based only on the evaluation of the corresponding patient files, laboratory findings and radiological examinations for the 214 study participants with a proven COVID-19 disease. As the team led by neurologist Ling Mao from Huazhong University of Science and Technology reports, 78 (36.4 percent) of them showed neurological manifestations that were more serious the overall COVID 19 disease was.
The most common observers observed dizziness (36 patients, 16.8 percent) and headache (28 patients, 13.1 percent). In addition, there were taste disorders in twelve patients (5.6 percent) and olfactory disorders in eleven patients (5.1 percent). Six patients (2.8 percent) suffered a stroke.
In an independent editorial to the study, neurologists Samuel Pleasure, Ari Green, and Andrew Josephson from the University of California split these manifestations into specific symptoms (loss of smell or taste, muscle weakness, and strokes) and non-specific symptoms (headache, loss of consciousness, dizziness, and seizures) ) on. In the case of non-specific symptoms in particular, it remains unclear whether these are an expression of the disease itself or are part of a systemic inflammatory reaction in patients who were already very ill. Future studies should examine this question.
Entry into the brain via olfactory nerves
“It is important that the authors found that the patients they examined with some of the most common specific symptoms, including odor or taste disorders and muscle disorders, tended to have these symptoms at the beginning of their clinical course,” said the three neurologists. This differs significantly from the neurological manifestations of Sars infections in 2002/2003, which were also triggered by a coronavirus.
In fact, Sars and Mers – also a coronavirus disease – are known to cause damage to the nervous system. For both infections it has been experimentally proven that the virus can enter the brain via the olfactory nerves in the nasal cavity.
In the case of Covid-19, it is now being discussed whether respiratory arrest could also be the result of neurological damage – for example, inflammation of the brain stem, where the control for the cardiovascular system and the respiratory tract is also located. From a neurological point of view, it is important to clarify how many of the serious illnesses are triggered by the involvement of the central nervous system, notes Peter Berlit, general secretary of the German Society for Neurology.
In view of the current Chinese study, physicians Pleasure, Green and Josephson see neurologists in their future “at the forefront of the pandemic”. The authors of the study consider it particularly important that doctors consider a Covid-19 infection in patients with corresponding neurological symptoms “in order to avoid a delayed diagnosis or misdiagnosis and to prevent further transmission”.