Central Nervous System Manifestations of Long COVID: A Systematic Review.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been one of the most widespread and devastating global pandemics, impacting hundreds of millions of people worldwide. After the cessation of active infection, the disease continues to have a disabling impact due to the persistence of fatigue, brain fog, anxiety, and depression - among the most common symptoms. This study explores the progression of neurological symptoms over 12 months and beyond following an initial diagnosis of COVID-19. Through an electronic search of eligible studies from PubMed, the Cochrane Trial Register, and Google Scholar, 10 studies were included for qualitative analysis. The systematic review highlights the similarities and differences in findings across the included studies. Olfactory dysfunction was prevalent in 0.9%-51% of individuals, and taste impairment was observed in 1.1%-21.3%. At 12 months, anxiety was more prevalent (3.5%-29%) than depression (3.5%-26%). Fatigue was the predominant neurocognitive complaint in 56% of individuals with severe COVID-19. Nearly half of individuals reported sleep difficulties. Memory impairment, followed by headaches and dizziness, also constitutes neurocognitive symptoms reported at 12 months. Our study found that there is a significant neurological burden one year following the diagnosis of COVID-19. Further studies exploring the pathological mechanisms of long-term COVID-19 are necessary to better delineate the mechanisms behind several long-term neurological manifestations of COVID-19.