Evaluation of the Daily Living Activity in Patients with Miastenia Gravis

The purpose of the work was to study changes in daily activity in patients with myasthenia gravis depending on the clinical form, immunological type and class of the disease. Material and methods. Using the activity of daily living scale, an analysis of changes in daily activity was performed in 182 adult patients with myasthenia depending on the clinical form, the immunological type of the disease, and the Myasthenia Gravis Foundation of America class of disease. Results and discussion. Among the examined patients there were 128 (70.3%) women and 54 men (29.7%), the ratio of women to men was 2.37: 1. Median age was 52.0 (34.0; 65.0) years. In patients in the general sample, there was a clinically significant decrease in daily activity (4 points and above). At the same time, in patients with ocular form, the level of decrease in daily activity was insignificant and did not reach the level of clinical significance, in contrast to the group of patients with generalized myasthenia where it was significantly lower and clinically significant (p <0.001). Patients with Myasthenia Gravis Foundation of America class II myasthenia (mild muscle weakness) did not achieve a clinically significant level of daily activity decrease and their score did not differ statistically from the ocular form (p = 0.998). The level of daily activity in patients with Myasthenia Gravis Foundation of America class III significantly decreases, compared to those of class I and class II (p <0.001, respectively). This is due to an increase in clinical manifestations (muscle weakness, fatigue), as well as due to possible worsening of the psycho-emotional state. The activity of daily living scale scores between subclasses A and B of class III do not differ statistically (p = 0.1). The lowest rates of daily activity were found in patients with Myasthenia Gravis Foundation of America class IV myasthenia, and significantly differed from the corresponding scores of patients with classes I-III myasthenia (p <0.001). As in patients with grades II and III, the daily activity in subclasses A and B of class IV did not differ statistically (p = 0.429). It was found that the level of daily activity of patients decreases with an increase in the degree of clinical manifestations (and, consequently, the class for Myasthenia Gravis Foundation of America). When performing Spirmen rank correlation, it was found out that the corresponding scores on the activity of daily living scale reliably correlated with the presence of antibodies to AchR (ρ = 0.18; p <0.05) and their titer (ρ = 0.43; p <0.001). However, no correlation relations existed with the presence or with the titre of antibodies to MuSK (ρ = 0.11; p> 0.05; ρ = 0.13; p> 0.05, respectively), with the presence of antibodies to SOX1 (ρ = 0.13; p> 0.05) and the presence of antibodies to titin (ρ = 0.07; p> 0.05). The daily living scale score reliably correlated with the Myasthenia Gravis Foundation of America class of myasthenia (ρ = -0.32; p <0.05). There were no relationships between the age of the first symptoms and the activity of daily living scale scores in the total sample (ρ = 0.03; p> 0.05). Conclusions. The obtained data confirmed that antibodies to acetylcholine receptors influence not only the development of pathological fatigue and weakness in myasthenia as the main pathogenetic mechanism in patients with the corresponding immunological type of myasthenia, but also may affect the daily activity of patients. The presence of antibodies to acetylcholine receptors and their titres, as well as the Myasthenia Gravis Foundation of America class of disease, significantly affect the daily activity of patients with myasthenia gravis.