COVID-19 Linked to Some Types of Brain Damage: Study

Over half a year into the COVID-19 pandemic, a number of studies have linked the disease caused by the coronavirus to certain types of brain issues and damage.

One paper published in the journal Brain found COVID-19 patients can experience hallucinations, strokes, and delirium.

The authors compiled cases of neurological problems in 43 COVID-19 patients treated at the National Hospital for Neurology and Neurosurgery in London between April 9 and May 15.

The cases were reported to a multidisciplinary team set up in March 2020 specifically to monitor neurological issues in COVID-19 patients.

They placed patients into five categories depending on their clinical features and scan results. The study involved 29 patients who tested positive for the coronavirus, and eight probably cases according to World Health Organization criteria. The 24 males and 19 females were aged between 16 to 85, and their symptoms ranged from mild-to-critical. Of eight patients who tested positive for the coronavirus, none had the virus in their cerebrospinal fluid.

Of the total cases, 10 saw their brain malfunction in a way that caused delirium, and appeared confused and disorientated. One experienced seizures. Another patient with no previous psychiatric problems suffered from psychosis and hallucinations, including seeing lions and monkeys in her house.

A further 12 patients had some form of brain inflammation, including one whose brain tissue died away, resulting in her death. Another with presumed early onset Alzheimer's experienced hallucinations, such as seeing people in her house and objects flying around the room.

Nine of the brain inflammation patients had ADEM, a rare condition that typically affects children and young people. The authors noted doctors in London would usually expect to see this many in five months, in a trend which they said warrants more research.

The team also found patients had strokes, and eight had nerve damage. Another five had conditions deemed miscellaneous which didn't fit into the other four categories.

The virus which causes COVID-19 is a member of the large coronavirus family of viruses. Patients with other forms of coronavirus, such as SARS and MERS, have also experienced neurological problems, the team said.

Co-author Dr. Michael Zandi of UCL Queen Square Institute of Neurology and University College London Hospitals NHS Foundation Trust, said in a statement: "We should be vigilant and look out for these complications in people who have had COVID-19.

"Whether we will see an epidemic on a large scale of brain damage linked to the pandemic—perhaps similar to the encephalitis lethargica outbreak in the 1920s and 1930s after the 1918 influenza pandemic remains to be seen."

Professor Cris S. Constantinescu of the Division of Clinical Neuroscience at the U.K.'s University of Nottingham Queen's Medical Centre, who did not work on the article, told Newsweek: "The variety and the multitude of neurological manifestations is striking in the large collection."

The study "confirms some suspicions of indirect damage due to the inflammatory response it [the virus] triggers, and also shows that one does not need to have severe lung infection to have neurological involvement with COVID-19."

Regarding the incidence of ADEM, Constantinescu said it's unusual for case to increase in middle-aged and older adults, and indicates the coronavirus is linked, "probably through immune mechanisms rather than direct viral invasion as the virus was not found in the brain or spinal fluid."

Constantinescu was most surprised by the "striking discrepancy between serious changes on MRI scans and the spinal fluid not looking too bad. Again this suggests that the mechanism is not direct destructive effect of the virus but the immune response it triggers."

The study was limited, he said, because some patients were suspected but not proven to have COVID-19.

Asked what readers should take away from the paper, Constantinescu said: "We need to remain vigilant as even mild respiratory infection with COVID-19 can affect the nervous system in many different ways."

This study is one of a number published recently to explore neurological issues in COVID-19 patients. Two separate papers in Journal of Alzheimer's Disease and The Lancet Psychiatryboth linked the condition to strokes and confusion.

Providing a potential clue to why these cases occurred, the authors of a paper released as a pre-print on the website ALTEX, found the COVID-19 coronaviurs could infect the cells of so-called human "minibrains" or "brainspheres" in a lab.