Long-lasting cognitive effects of COVID-19: is there a role of BDNF?

The Lasting Legacy of COVID-19: Exploring the Long-Term Effects of Infection, Disease Severity, and Vaccination on Health and Cognitive Function

“…Our results also showed that the effects of COVID-19 infection on cognitive performance and functions were weak; a finding that was in disagreement with the former studies that reported significant adverse effects of both mild and acute COVID-19 on cognition 8,9,11,23 . This finding was somewhat in agreement with Zhou et al 13 who reported no significant difference between their patient group and controls in cognitive functions except for continuous and selective attention, and also another study that found no significant difference between the patient group and controls in terms of cognition 24 .…”

“…However, this issue was addressed through our analyses of COVID severity in the current study. The analyses further revealed that being infected with COVID had positive effects on intelligence and memory and negative impacts on precision and reaction times; although these effects were non-significant and weak, these findings were in disagreement with those studies that reported impairment in cognitive functions in COVID patients 8 and in agreement with a study in which lower reaction times were reported in the patient group 13 .…”

“…In a study using iPad-based online neuropsychological tests, researchers found that 29 patients who had recovered from COVID-19 did not differ from their matched controls in the Trail Making Test (assessing cognitive processing speed and executive functions), Sign Coding Test (investigating visual scanning and perception, memory, and eye movement), and Digital Span Test (testing concentration, resistance to information interference, and instantaneous memory). However, they differed in the Continuous Performance Test (measuring impulse and continuous and selective attention through a recognition task of a pair, two consecutive pairs, and three consecutive pairs of animal pictures in parts one, two, and three of the test, respectively), showing that patients Visual Aural Digit Span Test Form B (VADS-B), found that the patient group compared to controls had significantly higher Stroop test word reading-spontaneous correction number (0.13 ± 0.39 vs 0.00 ± 0.00, p<0.05) and reading time (19.1 ± 3.7 vs 16.3 ± 2.7, p<0.01); saying the word color -number of wrong words (0.46 ± 1.13 vs 0.03 ± 0.17, p<0.05), spontaneous correction number (0.78 ± 0.92 vs 0.33 ± 0.68, p<0.01) and saying time (36.2 ± 10.8 vs 28.5 ± 5.0, p<0.01); saying the box's colorspontaneous correction number (0.2 ± 0.4 vs 0.0 ± 0.0, p<0.0) and saying time (12.1 ± 2.2 vs 10.2 ± 1.3, p<0.01), Stroop interference (11.7 ± 6.3 vs 8.0 ± 3.8, p<0.05) and speed factor duration (9.3 ± 1.5 vs 7.9 ± 1.2, p<0.01) collectively indicating worse attention, precision, and slower information processing in the patient group than the control group; in addition, the VADS-B test mean-scores were significantly lower in the patient group than in the controls (p<0.05); hence, according to these results, a decline in attention and short-term memory was observed in the patient group compared with the controls 27675 8 .…”

“…For example, although Zhou et al 13 found no significant difference between the patient group and controls in cognitive processing, executive functions, memory, concentration, and resistance to information interference, and they observed lower reaction times in the patient group, Demir et al 8 reported higher reaction times, slower processing speed, and lower resistance to Stroop interference in their patient group compared with controls. Similarly, among other findings, processing speed, attention, working memory, and executive functions were found to be more compromised in patients in another study 9 ; however, other research did not find a significant difference between the patients and controls in attention and executive functions 10 .…”

Aterosclerosis, Cardiovascular Disorders And Covid-19: Comorbid Pathogenesis

“…Brain derived neurotrophic factor (BDNF) serves as a proatherogenic mediator and is overexpressed in atheromas [47]. The same cytokine is a predictive marker of severe COVID-19 [48], but at the same time negatively correlates with severe post-covid cognitive impairment [49].…”