What was reported

Donadio, Mickle, Ostrowski, Mentis, Friedlander, Capogrosso and colleagues (Pittsburgh + Carnegie Mellon + Columbia) reported at the 5th International Scientific Congress on SMA (Budapest 2026, oral O42) that cervical spinal cord stimulation (SCS) improved upper-limb function in three non-ambulatory adults with SMA.

Mechanism

Pre-clinical data show SMA motor neurons exhibit not only cell death but also dysfunction from decreased proprioceptive input — leading to hyperexcitable motor neurons with prolonged refractory periods and paradoxically reduced firing rate. Spinal cord stimulation activates sensory afferents, and the team hypothesised that increased sensory input to motor neurons could rescue this circuit dysfunction.

Trial design (STUDY21080158)

• 3 non-ambulatory adults: SMA04 (male, 56 y, baseline RULM 8/37), SMA05 (female, 21 y, RULM 20/37), SMA06 (male, 60 y, RULM 34/37)
• Temporary epidural leads (29 days) placed over cervical spinal cord
• SCS delivered unilaterally, in absence of exercise (to isolate stimulation effects)
• Builds on prior work showing 4 weeks of SCS improved strength + gait + endurance in three ambulatory SMA adults

Why this matters

This trial addresses a circuit-level deficit that survives SMN restoration. Drugs do not fix the maladaptive excitation–inhibition imbalance in spinal motor circuits — neuromodulation may. SCS adds a device-based therapy class to the SMA toolkit, complementary to small-molecule, ASO, and gene-therapy approaches.

The 3-patient cohort is preliminary; longer follow-up + larger trials are needed to establish durability.

This is a Congress oral; third-party report. Spinal cord stimulation for SMA is investigational.