poSt Covid-19 Infection centraL sENsitisaTion

The COVID-19 pandemic is currently a serious global public health concern. This disease is
caused by a novel coronavirus which was first discovered in Wuhan, China in 2019 and later
spread rapidly throughout the world. Symptoms of the disease can manifest as fever, cough,
encephalitis, myalgia, fatigue, muscle weakness, arthralgia, anosmia, and impairment in other
bodily functions in the acute phase. In 17% to 67% of cases, COVID-19 patients will develop
acute respiratory distress syndrome (ARDS) and critical illness. Besides the impact on the
respiratory system, coronaviruses have an effect on other systems including the central
nervous system, cardiovascular system, musculoskeletal system, and gastrointestinal system.

The term central sensitivity syndrome (CSS) describes a group of medically nonspecific
disorders, such as fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome, for
which central sensitivity might be a common etiology. Despite the lack of a solid outcome
measurement, the Central Sensitization Inventory (CSI) was previously introduced as a
screening instrument for clinicians to help identify patients with a CSS. Furthermore,
quantitative sensory testing can be used to identify and quantify sensory disfunctions by
evaluating a variety of parameters including pain thresholds, temporal summation, and
conditioned pain modulation (CPM). Previous research in patients with chronic pain resulted
in less efficacious CPM, increased nociceptive facilitation and decreased pain thresholds.

In post covid-19 patients, potential long-term secondary effects on the musculoskeletal
system such as muscle weakness, decreased muscle mass, and myopathies have been brought under
attention. Persisting symptoms are a frequently reported complaint in patients recovered from
COVID-19 infection with at least 1 symptom, particularly fatigue and dyspnea. Fatigue is also
one of the core symptoms in central sensitisation disorders, leading to the hypothesis that
central sensitisation might be the underlying common etiology in chronic pain patients and
patients post COVID-19 infection. Therefore, the aim of this study is to evaluate whether
there are indicators of central sensitisation in patients post covid-19 infection.