Revised upper limb module in type II and III spinal muscular atrophy: 24-month changes.

Area of Science:

• Neurology
• Genetics
• Clinical Medicine

Background:

• Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder affecting motor neurons.
• Upper limb function is crucial for daily activities in SMA patients.
• Assessing functional changes over time is vital for treatment evaluation.

Purpose of the Study:

• To evaluate 24-month changes in upper limb function in type II and III SMA patients.
• To analyze functional decline using the Revised Upper Limb Module (RULM).
• To identify patient subgroups with significant functional changes.

Main Methods:

• A cohort of 107 SMA patients (54 type II, 53 type III) with 24-month follow-up was studied.
• The Revised Upper Limb Module (RULM) was used to assess upper limb function.
• Statistical analysis compared baseline and 24-month RULM scores.

Main Results:

• Overall, a mean decline of -0.79 points in RULM scores was observed over 24 months.
• Significant decline was noted in type II SMA patients, but not in type III.
• Non-ambulant type III and non-sitter type II patients showed the most pronounced decline, while ambulant type III patients remained stable.

Conclusions:

• Upper limb function in SMA patients generally declines over 24 months.
• Type II SMA and certain subgroups of type III SMA experience progressive functional loss.
• These findings aid in interpreting real-world data for new SMA therapies.