Almost nothing is surprising about the coronavirus. Its direct and indirect effects pass through the entire human body, from the skin to the lungs or the heart, with all possible levels of severity, from the absence of symptoms to death. The brain was not going to be less. Although some isolated cases have been known, now a study published in ‘Lancet Psychiatry’ aims to bring together all the neurological problems linked to COVID-19 and the list includes strokes, psychosis and even a syndrome similar to dementia.
The study analyses the cases of 153 patients spread across various UK hospitals who were notified by neurologists and other hospital specialists in just a few days in April when cases skyrocketed in this country. Ages vary between 20 to 90 years and the involvement of the brain is also very diverse. Of the entire sample, the researchers are left with 125 cases in which they were able to complete all the data and most of them have suffered some type of stroke, specifically 77.
The researchers also report encephalitis, an inflammation of the brain that can cause various symptoms, such as confusion and mobility difficulties, and other disturbances of brain functions. The authors of the workgroup all these symptoms as mental disorders that represent the second most common neurological problem, since it affected 39 of the studied patients. The authors of the study group all these symptoms as mental alterations that constitute the second most common neurological problem, since it affected 39 of the patients studied. Another 10 were diagnosed with psychosis— a pathology characterized by delusions or hallucinations, and 6 others had dementia-like cognitive problems.
How to explain this wide range of cerebral repercussions? The truth is that since the beginning of the pandemic the nervous system has been involved in the effects of the coronavirus since the loss of smell and taste were identified as common symptoms of the disease. Strokes appear to be related to clots also detected in other parts of the circulatory system, while other neurological problems may be among the incomes of older people. Still much remains to be known about SARS-CoV-2, the brain, and the nervous system in general.
In Spain, neurologists have also detected these problems, although they believe that some of them can be explained simply by the circumstances of the prolonged hospitalization suffered by many patients. The most common symptomatology, not only in the COVID-19 but in any serious patient admitted to the hospital, is ” confusion, depressive disorder, anxiety, insomnia and memory disorders,” David Perez Martinez explains to Teknautas, head of the Neurology Service of The Hospital Universitario 12 de Octubre in Madrid.
These are nonspecific symptoms that can appear in all types of hospitalized people – in the case of the coronavirus, some of them appear in a quarter of the hospitalized patients, especially if they are older, with serious pathologies. In this case “we don’t really know if they are directly caused by the virus or not”, but it can probably be explained by the isolation, the medication, the complications of mechanical ventilation or the generally poor condition.
However, “we have also seen a group of patients in whom specific neurological symptoms do appear that are not a product of hospital admission.” For example, in Hospital 12 de Octubre, twenty patients with strokes have been registered within the framework of covid-19 infection. Although they are very few compared to the total – about 4,000 patients have passed through this hospital – the expert points out that “the profile was totally atypical with respect to a normal stroke because they were young people.”
These strokes are not understood as a specific brain pathology, but within the blood circulation problems that SARS-CoV-2 causes in a generalized way. In fact, specialists speak of a “prothrombotic state” that can have various manifestations. “In these patients not only the strokes have been seen, but thrombosis to other arterial levels, not only in the brain. What happens is that sometimes a phenomenon of this type in the liver or kidney can go unnoticed except for some analytical alteration, while in the brain it produces a very striking clinical picture,” comments the expert. Everything indicates that the virus affects the vascular endothelium and generates an arterial injury that facilitates clots.
On the other hand, Spanish neurologists have also detected encephalopathy pictures, in which the patient begins to lose attention, suffer drowsiness and have movement disorders. Among them, researchers at the Hospital 12 de Octubre have recently published an article in the prestigious scientific journal ‘Neurology’ on myoclonus, that is, involuntary, brief and rapid movements, especially of the arms and legs.
The immune response against the nervous system
Another section would be the autoimmune syndromes that affect the peripheral nervous system, in particular Guillain-Barre syndrome and some of its variants. In this disorder, the body’s immune system attacks the nerves, causing their inflammation, muscle weakness, paralysis and other symptoms. “We have found this problem associated with COVID-19, although it also occurs in other infections when the immune system becomes overactive, fails its target and, instead of attacking the virus, damages the peripheral nerves,” he explains.
In the Madrid hospital, they have had Guillain-Barre cases and a patient with a much rarer variant, Miller Fisher syndrome, whose study was also published in the journal ‘Neurology ‘ last April along with that of another patient in the Prince of Asturias University Hospital of Alcala de Henares.
These exaggerated immune response problems are closely related to severe cases of COVID-19 in general, but also particularly to all brain pathologies derived from the disease. “Most of the cases with specific neurological complications were associated with patients who had severe symptoms, with respiratory failure and mechanical ventilation in some cases,” says Perez Martinez.
Unknowns about cognitive decline
With respect to psychosis and the dementia-like symptom described by the British researchers, he is very cautious, since a normal hospitalization or an ICU visit can trigger this type of consequences in the elderly. Confusion or memory disturbance is not a rarity upon discharge. “The problem is that a lot of things are mixed together and it is too early to tell what is going on. We have known for a long time that if an older patient with mild cognitive impairment is admitted to a hospital for a long time, due to serious illness and with the need for oxygen, usually comes out with a more striking cognitive disorder,” says the expert.
Hence, the hypothesis that the virus itself can affect the brain and induce a cognitive disorder remains a long way. “It is not yet known, you have to have a longer perspective over time and that is why we are now evaluating these patients to know what is happening,” he says.
However, “we have seen cases that surprise us, younger people who apparently do not have cognitive disorders and who have had very striking confusion pictures.” A possible explanation is in the treatments since some of the drugs that have been used can produce these types of adverse effects. Corticosteroids such as dexamethasone, which have shown positive effects – precisely because it can help fight inflammation caused by an exaggerated immune response – can cause a condition known as corticosteroid psychosis. “We have had a case,” says Perez Martinez.
In any case, all the neurological problems related to the coronavirus require more data and, above all, a long-term evaluation. Hospitals have created multidisciplinary units to follow up on sequelae in patients who are discharged, and an important part of their work is to monitor neuropsychological status through telephone monitoring and face-to-face appointments. However, it’s only been three months since the first recovered patients were able to go home, so much work remains to be done.