Glymphatic Dysfunction in Children With Type 2 and 3 Spinal Muscular Atrophy

Area of Science:

• Pediatric Neurology
• Neurodevelopmental Disorders
• Cerebrospinal Fluid Dynamics

Background:

• Spinal muscular atrophy (SMA) is linked to lower motor neuron degeneration and impaired brain development.
• The glymphatic system is crucial for maintaining brain homeostasis during development.
• This study investigates glymphatic system alterations in children with SMA types 2 and 3.

Purpose of the Study:

• To assess glymphatic system function in children with SMA.
• To correlate glymphatic changes with SMA clinical severity.
• To explore the impact of nusinersen treatment on glymphatic function.

Main Methods:

• Recruited 48 children with SMA and 53 typically developing controls.
• Measured glymphatic function using DTI-ALPS index, enlarged perivascular spaces (ePVS), and gBOLD-CSF coupling.
• Analyzed data with t-tests/Mann-Whitney U, FDR correction, and partial correlation.

Main Results:

• SMA children showed increased CSF volume, higher ePVS frequency, and a lower ALPS index compared to controls.
• CSF volume negatively correlated with SMA severity.
• Nusinersen-treated SMA patients exhibited increased CSF and a lower ALPS index post-treatment.

Conclusions:

• Glymphatic system dysfunction is a feature of SMA in children.
• Glymphatic alterations correlate with SMA clinical severity.
• These findings highlight a novel aspect of SMA pathophysiology.