Abstract
Introduction: Pain syndromes, anxiety, and depression are common syndromes in multiple sclerosis (MS). Comorbidity of pain and depression or pain and anxiety exists in up to one-third of MS patients. Based on the biopsychosocial model of pain, given the high prevalence of these symptoms and their frequent combination in MS, which is significantly higher than in the general population, we can hypothesize the relationship between the characteristics of pain and anxiety and depression in patients with MS. Objectives: To assess the prevalence of anxiety and depression among MS patients with pain syndromes and analyze the relationship between anxiety and depression with pain syndromes' characteristics in patients with MS. Methods: Data were collected prospectively at Lviv Regional Multiple Sclerosis Center. 120 randomly selected patients with a confirmed diagnosis of multiple sclerosis were examined. 104 of them had pain syndromes during the last month. Complaints and medical history, analysis of medical records, neurological and general medical examination of the patients were collected. Depressive symptoms and anxiety were assessed in all patients using the Hospital Anxiety and Depression Scale (HADS) questionnaire. In patients with pain syndromes, the Visual analogue scale (VAS), Short-form McGill Pain Questionnaire 2 (SF-MPQ-2), Pain Detect were used to assess pain characteristics. Results: The levels of anxiety and depression were higher in the group of MS patients with pain. The level of anxiety was 9.0 [6,0; 12,75] in the group with pain and 7.0 [4,0; 9,25] in the group without pain (p=0.04). The level of depression was 7.0 [4,0; 10,0] in the group with pain and 4.0 [1,75; 6,0] in the group without pain (p<0,01). It was found that part of MS patients with pain syndromes with anxiety was 36.5%, and 29.8% had a subclinical level of anxiety; part of MS patients with pain syndromes with depression was 19.23%. The proportion of patients with anxiety was highest in patients with neuropathic pain: 56.3% ± 8.8% vs. 22.4% ± 6.0% with nociceptive, p<0.01. A similar situation is observed in patients with depression. The share of patients with depression was higher in the group with neuropathic pain 37.5% ± 8.6%, compared to 14.3% ± 5.0% with nociceptive, p=0.02. The proportion of patients with MS without signs of anxiety and depression is significantly higher among patients with nociceptive pain (p<0,05). Also, the correlational relationship between the level of anxiety and depression with the level of the neuropathic type of pain manifestation was found (r=0,40; p<0,01 and r=0,30; p<0,01). Levels of anxiety and depression correlated with the average pain intensity per month (r = 0,21; p=0,03) and did not have a statistically significant relationship with pain intensity at the time of examination and the strongest pain for the last month. The anxiety and depression had correlations with all components of the structure of pain syndromes (according to sfMPQ-2), but the most pronounced direct correlation was found between anxiety and the affective component of pain (r=0,57; p<0,01). It was also found that the level of anxiety was proved to be higher in patients who have 2-3 pain syndromes, than in patients with one pain syndrome: 12.0 [8,0; 14,0] points against 8.0 [5,0; 11,0] points, p<0.01. Besides, this localization of pain in the arms, shoulders and back was related to higher levels of anxiety (r=0.22; p=0.03). Conclusion: Pain syndromes, anxiety, and depression are widespread among patients with MS and there is a relationship between them. MS patients with pain have higher levels of anxiety and depression than MS patients without pain. It is also noteworthy that among MS patients with pain syndromes, high levels of anxiety are detected. Anxiety and depression also have a pronounced relationship with a neuropathic component of pain in patients with MS. Besides this, the presence of more than one pain syndrome, high average pain intensity per month is associated with higher levels of anxiety and depression. The localization of pain in the arms, shoulders and back is related to higher anxiety levels. These discoveries, combined with modern neuroimaging technologies used in the next step of our study, will provide a better understanding of both pain and its structure, as well as anxiety and depression