There are many questions still open on the effects that Covid can have on the brain: the opinion of experts
"The brain at the time of Covid". This is the "title" of the 2021 edition of the World Brain Week, which starts tomorrow, according to experts from the Italian Society of Neurology. There are still many open questions in this sense: first of all it is necessary to understand if the problems linked to the Sars-CoV-2 infection are always destined to resolve themselves over time without reaching prolonged sequelae, the so-called "Long-Covid" . And it is just one example of the themes that this week of awareness raising, which starts from a certainty: hundreds of clinical studies show that there are neurological complications of the infectious picture.
Why is there talk of "Neuro-Covid"?
The infection can affect both the central nervous system – with headache, dizziness, disturbances in the state of consciousness (confusion, delirium, up to coma), encephalitis, epileptic manifestations, motor and sensory disturbances, higher incidence of stroke with greater severity – and the peripheral nervous system, with loss or distortion of the sense of smell, taste, neuralgia and Guillan-Barrè syndrome.
Also in the post-illness phase various problems emerged such as protracted asthenia, concentration disturbances, memory and behavioral disturbances, which could be linked to small vascular or inflammatory damage of the nervous system, with long-term repercussions. As if that were not enough, in the months of prolonged isolation and alteration of the rhythms of life and social habits, a worsening of behavioral symptoms and an increase in cognitive impairment was observed for the more than 1,200,000 people affected by dementia in Italy, of which 720,000 from Alzheimer's, and a higher incidence of sleep disorders, which affect an average of 12 million Italians and which affected about 24 million during the pandemic.
"Over the last year we have witnessed continuous confirmation of the correlation between Covid 19 and neurological diseases – reports Gioacchino Tedeschi, President of the Italian Society of Neurology and Director of Neurological Clinic and Neurophysiopathology, AOU University of Campania" Luigi Vanvitelli "of Naples. Precisely for this reason the Italian Society of Neurology is carrying out research projects and clinical studies to investigate this link in depth, with the aim of clarifying the extent and duration of neurological effects, and developing clinical protocols that help specialists to intervene promptly to counteract the damage ".
On the assistance front, in any case, there has been and will always be more space for remote medicine. "In the near future, the remote neurological physical examination could be further implemented with the possible use of accelerometers (by now they are present in most common smartphones), which would allow a more accurate examination of walking, posture and balance, of devices that allow to quantify the sensory experience or "in-home neuro kits", with vision cards, tuning forks, pins and cotton balls, already in use now for the evaluation of the EDSS scale in Multiple Sclerosis – says Tedeschi " .
Thus the virus "attacks" the nervous system
The disease can affect the brain in a number of ways. It is known that direct infection of neural cells by the coronavirus can occur, just as the brain can be affected by severe generalized inflammation that "floods" it with pro-inflammatory agents, thus damaging nerve cells.
"The Sars-CoV-2 virus uses ACE2 as the main attack receptor of the" spike protein "for cellular entry – says Paolo Calabresi, Professor of Neurology and Director of Neurology at the Gemelli Polyclinic in Rome. ACE2 protein was observed in the vascular system, but to a lesser extent in the lining of the cerebral vessels. However, RNA sequencing has shown its presence, albeit modest, in the human brain ".
In a recently published study of symptomatic patients admitted to the first wave of Covid-19, 213 patients tested positive for Sars-Cov-2 while 218 patients tested negative and were used as a control group. “As regards the manifestations of the central nervous system, a higher frequency of headache, hyposmia and encephalopathy always correlated to systemic conditions (fever or hypoxia) was observed in positive patients – specifies Calabresi. Furthermore, muscle involvement was more frequent in Sars-CoV-2 infection. The neurological manifestations of Covid-19 therefore constitute a major public health challenge not only for the acute effects on the brain, but also for the long-term damage to brain health that could result from it. These delayed manifestations could also be present in patients who did not show neurological symptoms in the acute phase ”.
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