The influence of intensity and neuropathic component of pain syndrome on the quality of life in patients with multiple sclerosis

Abstract

The aim of the work. To analyze the influence of intensity and neuropathic component of pain syndrome on the quality of life structure characteristics in patients with multiple sclerosis (MS). Materials and methods. 104 MS patients with different types of MS course and complaints of pain during the last month were examined in the Lviv Regional Multiple Sclerosis Center. The patients were interviewed using standardized questionnaires (Pain Detect, VAS, SF-36) followed by an analysis of the pain characteristics influence on the quality of life. Results. When assessing the influence of the main characteristics of MS course, the relationship between the physical component of quality of life and levels of disability (EDSS) and the total number of relapses was found (r = -0.60, P < 0.01; r = -0.34, P < 0.01, respectively). However, the mental component of quality of life had no significant relationship with the level of disability and the number of relapses. The average pain intensity within a month on the VAS scale was 5.0 [4.0; 7.0]. 24.0 % of patients had low-intensity pain, 54.8 % – moderate, 21.2 % – high. In MS patients with low-intensity pain within a month, 5 of the 11 quality of life indicators were significantly higher, in particular, the overall physical component of quality of life – 38.1 [33.8; 48.5] % in low-intensity pain against 31.8 [28.1; 38.7] %, P = 0.02 – in moderate. In MS patients, the level of both physical (r = -0.25; P = 0.01) and mental (r = -0.21; P = 0.03) component of quality of life decreased with increasing pain intensity. The most notable correlation was observed between intensity of pain and such characteristics of quality of life as energy/fatigue (r = -0.37; P ˂ 0.01) and emotional well-being (r = -0.28; P ˂ 0.01). In 30.8 % of patients, pain was neuropathic, in 47.1 % – nociceptive, in 22.1 % – undetermined. MS patients with the neuropathic type of pain had significantly lower scores, 7 out of 11 indicators of quality of life, largely the mental component, than scores in MS patients with nociceptive type (Р < 0.05). Correlation analysis showed the association between an increase in the manifestation of neuropathic pain component and a decrease in all quality of life characteristics, except in health change. In MS patients with a neuropathic component, in increasing level of its manifestation, the mental component of health decreased clearly (r = -0.36; P ˂ 0.01), namely its social functioning characteristic (r = -0.35; P < 0.01). Conclusions. In MS patients, increasing intensity of pain decreases both physical and mental components of quality of life with the most significant decrease in energy/fatigue and emotional well-being as parts of the mental component of quality of life. The neuropathic component of pain and the level of its manifestation are largely associated with a decrease in the mental component of quality of life as the overall indicator and social functioning as its structural element.