The Impact of Comorbidities and Motor Impairment on the Quality of Life of Patients with Spinal Muscular Atrophy: A Case–Control Study

Introduction: Spinal muscular atrophy (SMA) is a genetically determined disease primarily leading to muscle weakness, but now, it is considered a systemic disease with changes in various tissues and organs. In our study, we aimed to compare quality of life (QoL) outcomes in patients with SMA in relation to the degree of motor limitation and comorbidities, mainly internal medicine diseases. Methods: We included 35 adult patients with SMA and 36 healthy volunteers. Thorough medical histories were taken focusing on comorbidities, and neurological examinations incorporating assessments using functional motor scales were performed. QoL was assessed based on the World Health Organization Quality of Life Brief Version (WHOQOL-BREF) questionnaire. Results: SMA patients and controls were comparable in terms of scores in the questionnaire’s main domains. SMA patients presented significantly higher levels of satisfaction with their medical care than controls. Patients with more advanced SMA had significantly better scores on certain questions, e.g., those related to health satisfaction or leisure activities. A total of 71.4% of SMA patients had comorbidities, ranging from one to three in individual patients. SMA patients with comorbidities did not show worse QoL. Negative correlations were found between the number of comorbidities in SMA patients and individual questions on the WHOQOL-BREF questionnaire. Conclusions: Patients with SMA were satisfied with their medical care. Better scores on some questions in more advanced SMA may have been due to better adaptation to disease-related limitations. The presence of single comorbidities did not affect QoL, but a higher number of comorbidities negatively correlated with QoL.