MRI Scan Reveals 'Viral Brain Invasion' of Coronavirus

Doctors have found magnetic resonance imaging (MRI) evidence of the ability of the novel coronavirus (SARS-CoV-2) to invade the brain based on brain scans of a COVID-19 patient with loss of taste and smell.

The patient was a 25-year-old female radiographer who had been working in a COVID-19 ward in an Italian hospital and did not have any significant medical history. She developed a mild dry cough that lasted for a day and later experienced severe loss of smell and taste. Doctors examined the patient’s nose but did not find any problems and her chest scans also came clear. However, an MRI brain scan revealed changes in adjacent areas in her nose and olfactory nerves, according to a case study published in the journal JAMA Neurology. The doctors believe that this is the first report of in vivo human brain involvement in a patient with COVID-19 showing a signal alteration compatible with viral brain invasion in a cortical region (i.e., posterior gyrus rectus) that is associated with olfaction. The doctors performed a follow-up MRI scan after 28 days and found that her symptoms had eased and she later recovered from anosmia. The doctors also performed brain scans of two other COVID-19 patients with anosmia 12 and 25 days after their symptoms started, but found no issues.

Based on the MRI findings, including the slight olfactory bulb changes, the doctors have suggested that SARS-CoV-2 might invade the brain through the olfactory pathway and cause an olfactory dysfunction of sensorineural origin, although cerebrospinal fluid and pathology studies are required to confirm this hypothesis. According to the study, observations of normal brain imaging in other patients with COVID-19–associated olfactory dysfunctions and the disappearance of the cortical MRI abnormalities in the follow-up study of the patient indicate that imaging changes are not always present in COVID-19 or might be limited to the very early phase of the infection. The doctors have further suggested that anosmia can be the predominant COVID-19 manifestation and should be considered for the identification and isolation of patients with infection to avoid the spread of the disease.