Women who test positive for SARS-CoV-2 and the lack of smell detected changes, the signal from the cerebral cortex of the brain, reported in JAMA Neurology. They probably occur in the early stages of the disease, as repeated test after four weeks they are no longer found. As stated by the authors, the influence of SARS-CoV-2 on the brain discovered for the first time.
One of the most frequent symptoms COVID-19 — loss of smell and taste, but in the list of sites of infection have included it immediately, from the start of a pandemic, it paid little attention. Therefore, the 25-year-old employee of one of the Italian hospitals, which treat coronavirus patients, three days after the loss of taste and smell (and the day before that she had a weak dry cough, but the temperature remained within the normal range) are first sent for a brain MRI and a chest x-ray. The history of her illness, described Letterio Politi (Letterio S. Politi) from the Clinical Institute “Humanitas” in Milan, his colleagues from the same Institute and staff of the Neurological Institute Carlo Besta.
X-rays revealed no pathological changes in the lungs, and MRI mode FLAIR showed enhanced signal from the white matter of the rear part of the straight gyrus in the right hemisphere and olfactory bulbs. In this case the patient had no brain injury, seizures, or hypoglycemic episodes that could provoke such changes. Since the number of infected COVID-19 in Italy at that time have already seen the loss of taste sensitivity and olfactory, the patient swabbed for coronavirus, and it was positive.
On repeat MRI, which was done four weeks after cough onset in the patient, the white matter of the direct convolutions already looked fine, and olfactory bulbs signal from it, too, has become less pronounced (in this case good). Sense of smell also returned. The other two patients with COVID-19, which was absent sense of smell, MRI at 12 and 25 days after onset of symptoms revealed no abnormalities in the brain. The authors of the study suggested that the virus causes changes in white matter only in the first days.
Straight gyrus receives information from the olfactory bulbs, and hippocampus and other structures within the limbic system, and sends signals to the number of nuclei of the thalamus, hypothalamus and brain stem. The researchers suggested that at least some patients COVID-19 respiratory failure may occur due to the effect of the virus on these areas of the brain.
From the editor
Although the article does not say directly, perhaps the authors meant that in the brain stem respiratory centers are located, and SARS-CoV-2 can kill neurons in them. At least know that so they can influence SARS-CoV-1, responsible for the epidemic of “atypical pneumonia” 2002-2003.