Stanford Medicine's senior research scientist Dr. Tina Duong has provided crucial insights into the evolving landscape of spinal muscular atrophy (SMA) assessment and treatment, highlighting the need for age-appropriate functional measures across the patient spectrum.
Adapting Assessment Tools for Different Age Groups
The traditional functional assessments for SMA, primarily developed for pediatric patients, are undergoing significant modifications to better serve the adult patient population. The CHOP INTEND scale, originally designed for weak infants, has proven impractical for adult patients, leading to the development of more suitable alternatives.
"We ended up modifying it into what we call the CHOPATEND, which took out the lifting parts, and then eventually we designed the ATEND, a scale that's designed to only assess weaker individuals in the wheelchair," explains Dr. Duong. These adaptations reflect the practical challenges of evaluating adult patients who typically remain in wheelchairs due to contractures and safety concerns.
Impact of Treatment on Disease Classification
The introduction of disease-modifying treatments has complicated the traditional classification system of SMA types. Dr. Duong notes that presymptomatic treatment is creating new phenotypes that differ significantly from historical presentations. "We're seeing clear differences between the previous untreated phenotype and a treated phenotype, and they definitely look different," she states.
Age-Specific Disease Progression and Treatment Outcomes
Treatment outcomes vary significantly across age groups. While infants may show dramatic motor skill improvements, teens and adults typically experience more modest benefits:
- Infants: May achieve normal developmental milestones with presymptomatic treatment
- Teens: Face challenges related to growth and orthopedic complications, particularly scoliosis
- Adults: Generally maintain rather than improve motor function with treatment
Emerging Clinical Considerations
The evolution of treatment options has revealed new clinical challenges and considerations. Dr. Duong highlights the emergence of different scoliosis patterns between infant and teenage populations, with infants developing more kyphotic scoliosis. This observation has prompted discussions about optimal support strategies during skill development.
"As parents and clinicians, we really want them to attain sitting, but they don't have the trunk control to be able to sit fully upright," Dr. Duong explains, emphasizing the need to balance therapeutic goals with potential long-term complications.
Future Directions in SMA Care
The field continues to evolve, with researchers and clinicians working to:
- Develop more appropriate assessment tools for different age groups
- Better understand the impact of early intervention
- Refine treatment approaches for various patient populations
- Address emerging complications in treated patients
These developments represent significant progress in SMA care while highlighting the ongoing need for age-appropriate assessment tools and treatment strategies.
