The influence of COVID-19 on peripheral nervous system

SARS-CoV-2 virus uzročnik je trenutačne pandemije bolesti uzrokovane koronavirusom (COVID-19). Virus pripada porodici koronavirusa, heterogenoj skupini ovijenih, jednolančanih, pozitivno usmjerenih RNA virusa. Koronavirus kodira 4 do 5 strukturnih proteina od kojih je protein šiljka (S protein) ključan za ulazak virusa u stanice domaćina. Vrata ulaska virusa u stanice domaćina je preko receptora angiotenzin konvertirajućeg enzima 2 izraženom na stanicama brojnih tkiva uključujući i živčani sustav. SARS-CoV-2 može zahvatiti SŽS putem dvaju direktnih mehanizama (retrogradne neuralne diseminacije i hematogene diseminacije) ili indirektnim putem. Zbog svojih složenih i još nepoznatih patoloških mehanizama, COVID-19 predstavlja veliku prijetnju čitavom živčanom sustavu. Kako se infekcija širi, sve je više dokaza koji upućuju na neurološke i psihijatrijske manifestacije COVID-a. Glavobolja, vrtoglavica, olfaktorne i gustatorne smetnje česte su neurološke manifestacije opisane u literaturi. Studije opisuju i teže neurološke manifestacije poput cerebrovaskularnog inzulta, tromboze venskog sinusa, encefalitisa, rabdomiolize i Guillain Barré sindroma. S obzirom da je riječ o novom koronavirusu, mnogi aspekti COVID-19 još uvijek ostaju nejasni, a povezanost SARS-CoV-2 virusa i živčanog sustava postaje sve veća meta istraživanja.SARS-CoV-2 virus is the causative pathogen of the recent pandemic of coronavirus disease 19 (COVID-19). Virus belongs to a family of coronaviruses, a heterogenous group of enveloped, single stranded, positive sense RNA viruses. Coronavirus encodes 4 to 5 structural proteins one of which is the spike protein (S protein), essential for entry of virus into host cells. The gateway for invasion into human host cells is through angiotensin-converting enzyme 2 (ACE2) receptor expressed on cells of multiple tissues including the nervous system. SARS-CoV-2 may affect CNS through two direct mechanisms (neuronal retrograde dissemination and hematogenous dissemination) or through indirect routes. Due to its complicated and still unknown pathogenic mechanisms, COVID-19 poses a big threat to the whole nervous system. As the infection spreads, there is increasing evidence of neurological and psychiatric involvement in COVID-19. Headache, dizziness, olfactory and gustatory dysfunctions are common neurological manifestations described in the literature. Studies describe more severe neurological manifestations such as cerebrovascular insults, cerebral venous sinus thrombosis, encephalitis, rhabdomyolysis and Guillain-Barré syndrome. Considering the fact that its a new coronavirus, many aspects of COVID-19 still remain unknown while connection between SARS-CoV-2 and nervous system becomes a major target for research