Frequency of neuropathic pain in pain in post-COVID-19 patients

Objective: : Pain is a sensory, affective and unpleasant sensation originating from any part of the body, associated with actual or potential tissue damage, related to the patient's past experiences. Neuropathic pain is pain associated with injury, dysfunction, or change in excitability of a part of the peripheral or central nervous system. COVID-19 is a common pathology that can affect various organs, including the central and peripheral nervous system, and may present with pain in certain parts of the body. In our country, studies investigating the pain areas caused by COVID-19 disease in the body and the frequency of neuropathic pain have not yet been conducted. In this study, we aimed to determine the frequency of neuropathic pain in ongoing pain in the post-COVID period in patients who had COVID-19. Methods: Patients between the ages of 18-90 who had covid-19 disease (positive PCR test result) were included in the study. The study was planned as a prospective observational study. Demographic data of the patients included in the study were recorded. The severity of the COVID-19 disease (presence and duration of symptoms, duration and number of treatment, whether there was any infection-related finding in Thorax CT, whether there was hospital or intensive care admission) was recorded by asking the patient himself. The blood and radiological examinations available during the active disease period were obtained from the health registry systems. Pain in the active period of the COVID-19 disease, in the last 1 month, and in the last 1 week was questioned with the VAS score. The "Extended Nordic Musculoskeletal System Questionnaire (GNKISA)" was used to question musculoskeletal pain in patients who have had COVID-19 disease. The LANSS(Leeds assessment of neuropathic symptoms and signs) neuropathic pain questionnaire and the Pain-DETECT(PDQ) neuropathic pain questionnaire were used to investigate the neuropathic component of pain in the musculoskeletal system. Results: A total of 209 participants, 119 (56.9%) female and 90 (43.1%) male, were included in the study. The mean age of the participants was 37.5±12.0 (min=19-max=74) years. 73 (34.9%) of the patients participating in the study had additional disease. The mean duration of the patients after COVID-19 was found to be 5.76±2.95 (min=0.5-max=12) months. 199 (95.2%) of the patients have symptoms of COVID-19. Only 10 patients (4.8%) were asymptomatic patients who were found to be positive for COVID-19 PCR. The most common COVID-19 symptoms were pain (77%), fatigue (68.4%) and myalgia (67.5%). These are respectively headache (59.3%), arthralgia (56.0%), anosmia-ageusia (50.7%), fever (38.3%), cough (36.4%), shortness of breath (% 22), chest pain (17.2%), diarrhea (15.3%), nausea (11.5%), vomiting (7.2%), skin problems (6.2%), thromboembolism (1%) 9), depression (1.4%). According to the LANSS score, 6 (2.9%) of the patients have neuropathic pain, while according to the PDQ score, 12 (5.7%) of the patients have neuropathic pain. Although it varies depending on the evaluation parameters, the frequency of post-COVID-19 neuropathic pain was found to be between 2.9-5.7% in our patient group. There was no significant difference between the presence of neuropathic pain after COVID-19 and sociodemographic characteristics, presence of additional disease, treatment status, treatment type, blood values, chest X-ray and CT, whether there is infection-related involvement or not. In our study, headache (59.3%), anosmia-ageusia (50.7%), thromboembolism (1.9%), and depression (1.4%) were found after COVID-19 infection. There was no significant difference between the presence of headache, thromboembolism, anosmia-ageusia, and depression in terms of the presence of neuropathic pain according to the PDQ and LANSS scales. When we look at the distribution of the Extended Nordic Musculoskeletal System questionnaire data in our study, it is seen that the most painful regions in our study were the back (20.1%), lumbal (15.3%) and knee (11.5%). According to PDQ, the rate of having problems in the neck (p=0,012), back (p=0,017), elbow (p=0,017), hand/wrist (p=0,002), lumbal (p<0,001), knee (p=0,001) and foot/ankle (p=0,002) regions was found to be significantly higher in those with neuropathic pain. According to LANSS, the rate of having problems in the lumbal (p<0,001) and knee (p=0,012) regions of those with neuropathic pain was found to be significantly higher. Conclusion: In our study, we aimed to determine the frequency of neuropathic pain in ongoing pain in the Post-COVID period in patients with COVID-19 infection. According to our results, we found that musculoskeletal pain most frequently persisted in the back, lumbal and knees after COVID-19 infection. In addition, although it varies depending on the evaluation parameters, the frequency of post-COVID neuropathic pain was found to be between 2.9-5.7% in our patient group. The most common symptoms in the post-COVID period; While it is defined as fatigue and muscle pain, the frequency of neuropathic pain is also at an significant level. Studies investigating the etiology and frequency of neuropathic pain in the post-COVID period associated with COVID-19 along with known neurological symptoms will be beneficial.