Symptoms That Contribute to SMA Disease Burden Clarified in New Study

Children with a diagnosis of spinal muscular atrophy (SMA) revealed the symptoms that heavily affect their disease burden in a study published in Journal of Child Neurology.

SMA is a hereditary disease that is defined by a degeneration of anterior horn cells and muscle weakening. This study aimed to report the most common and important symptoms of SMA in children with the diagnosis.

Caregivers of children with SMA were eligible to participate in the interviews, with all participants recruited from the CureSMA registry. Interviews were conducted from March 6 to September 24, 2019, and a cross-sectional survey was given online from January 15 to June 3, 2020.

Qualitative interviews with caregivers of children with SMA were conducted over the phone and through Zoom. Caregivers were asked open-ended questions about the symptoms that they believed had the greatest effect on the lives of their children. Questions were based on symptoms reported in the medical literature about SMA and identified symptoms in neurodegenerative conditions.

The cross-sectional study included symptoms of importance that were identified through the qualitative interviews and in other populations; these were 146 individual symptoms that represented 17 symptomatic themes (eg, inability to do activities, fatigue, weakness, problems with shoulders or arms, and problems with fingers or hands). Demographic data were also collected.

Caregivers were asked how much a symptom affected their child now and the symptoms were assessed on a scale of 0 (their child not experiencing it) to 6 (their child was severely affected by it). Caregivers were given an option to decline answering any question.

There were 16 caregivers interviewed for this study, and most were women (n = 13) with an average (IQR) age of 37 (29-51) years. There were 11 participants who identified as White. The children included 9 girls, and their average age was 5 (1-11) years. The interviews with the caregivers gave the researchers 670 quotes that described symptoms of SMA, of which 260 potential symptoms of importance were identified to form the 17 symptomatic themes.

Seventy-seven caregivers completed the survey, 96.1% of whom were from the United States and most whom were women (84.4%). The mean age of the caregivers was 37 (24-73) years, and more than 70% had a college degree or postgraduate degree. There were 31 boys and 46 girls represented in the survey who had a mean age of 4.7 (4 months-12 years) years.

The most prevalent symptoms in the children surveyed were inability to do activities (93.5%); hip, thigh, or knee weakness (90.8%); and fatigue (85.7%). Difficulty with physical activity (95.9%), muscle weakness (94.4%), and leg weakness (93.8%) had the highest prevalence among the 146 symptoms reported.

Hip, thigh, or knee weakness (2.64); choking or swallowing issues (2.43); and inability to do activities (2.38) scored the highest in the average life impact among the symptomatic themes. Difficulty with uneven ground (3.29), difficulty standing (3.16), and difficulty getting off a toilet (3.16) were the individual symptoms with the highest average life impact score.

Hip, thigh, or knee weakness (2.39); inability to do activities (2.22); and back, chest, or abdominal weakness (1.96) were the symptomatic themes that had the highest population impact. Muscle weakness (2.9), difficulty standing (2.68), and leg weakness (2.66) earned the highest population impact score of the individual symptoms.

There were some limitations to this study. The sample population may not represent the full pediatric population with a diagnosis of SMA, and caregivers in only 1 registry were represented. Participation could have been limited due to a lack of willingness to participate during the global pandemic, and children with mild disease may also have been underrepresented.

The researchers concluded that this study improved on knowledge about the symptoms that affect children with SMA the most and which have the greatest effect on their quality of life.

Reference

Rosero S, Weinstein MS, Seabury J, et al. Disease burden in children with spinal muscular atrophy: results from a large cross-sectional study. J Child Neurol. Published online December 19, 2022. doi:10.1177/08830738221135918