Even mild COVID-19 can cause structural and functional alterations in the brain that may lead to neuropsychiatric disorders , such as anxiety , depression , fatigue and somnolence , as well as adverse effects on well-being , health and work capacity .
Issue 34.1 WINTER 2025
Ítalo Karmann Aventurato presented the results of a study showing verbal memory impairment in patients infected by all four strains . The study was also led by Yasuda and reported in the same journal .
Economic impact The impact of long COVID on work capacity was the focus of a presentation by Gabriel Monteiro Salvador , who had a scientific initiation scholarship from FAPESP . Persistent neuropsychiatric symptoms such as somnolence , fatigue , anxiety and depression correlated directly with impaired work capacity in COVID-19 survivors , he said . The study , also overseen by Yasuda , is available in the same issue of Neurology .
Initially , a group of bank workers with similar characteristics in terms of job description , routine and schooling answered a questionnaire called the Work Ability Index ( WAI ), designed to arrive at an assessment of problems relating mainly to memory and cognition . In a follow-up assessment some months later , 62.5 % of the participants still had reduced WAI scores .
“ The economic impact of these people ’ s health problems is evident , underscoring the urgent need for specific treatment to reduce the loss to both the individuals concerned and society as a whole ,” Salvador said .
Quantifying fatigue in practice Fatigue is one of the symptoms most frequently reported by patients with long COVID , but the term is typically generic and lacks a clear definition . To quantify fatigue , researchers at UNICAMP ’ s Center for Biomedical Engineering ( CEB ) led by Leonardo Elias , a professor at the School of Electrical and Computer Engineering ( FEEC-UNICAMP ), developed a set of tests to measure muscle contraction and force , neuromuscular function , hand muscle fatigability and manual dexterity .
The participants in the experiment were asked to perform a number of tasks , during which index finger abduction force and first interosseous dorsal muscle contraction force were measured with sensors and electromyography , a technique for recording the electrical activity produced by skeletal muscles . They were also submitted to the Nine Hole Peg Test , a standardized assessment used to measure finger dexterity .
Despite limitations such as the small number of participants and the possible influence of anxiety and depression symptoms , the study showed that motor skills may be impaired in patients with symptoms of fatigue due to long COVID . For example , motor unit force-frequency relationships were abnormal in reaction tasks , although reaction time was preserved . In the Nine Hole Peg Test , the patients underperformed with the dominant hand compared with the control group .
“ The possible explanations for these results include increased intercortical inhibition [ a neurophysiological process in which the activity of neurons in the cortex is reduced ] and GABAergic pathway dysfunction [ impairing regulation of cognitive and emotional processing ], alterations in executive functions [ cognitive skills relating to control of actions , emotions and thoughts ] and greater perceived fatigue ,” Elias said . g
Even mild COVID-19 can cause structural and functional alterations in the brain that may lead to neuropsychiatric disorders , such as anxiety , depression , fatigue and somnolence , as well as adverse effects on well-being , health and work capacity .
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