Improved Sensation With Transcutaneous Spinal Cord Stimulation Following Chronic Spinal Cord Injury.

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Spinal Cord Injury Research

Background:

• Sensory recovery is often overlooked post-spinal cord injury (SCI), despite its importance for motor control and injury prevention.
• The Up-LIFT trial demonstrated that targeted transcutaneous spinal cord stimulation (tSCS) plus rehabilitation enhances upper extremity (UE) strength and function.
• This study investigates the clinical and functional significance of sensory improvements following tSCS and rehabilitation.

Purpose of the Study:

• To analyze the clinical and functional impact of sensory improvements after tSCS combined with rehabilitation in individuals with chronic, incomplete cervical SCI.
• To determine the magnitude, distribution, and meaningfulness of sensory changes.
• To assess the relationship between sensory improvements and functional outcomes.

Main Methods:

• Sixty participants with chronic, incomplete cervical SCI underwent a 4-month intervention (2 months rehabilitation + 2 months tSCS + rehabilitation).
• Sensory function was evaluated using the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) and Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP) exams.
• Statistical analyses included assessing changes in sensory metrics and using regression models to correlate sensation and motor abilities with functional outcomes.

Main Results:

• tSCS + rehabilitation significantly improved ISNCSCI-UE light touch and pin prick scores (p ≤ 0.01), with over 50% of participants showing improvement in sensory deficits.
• 53% of participants regained new upper extremity sensation post-tSCS intervention.
• GRASSP palmar sensibility improved significantly (p = 0.006), particularly at the C8 dermatome. Sensory scores correlated with functional outcomes (e.g., CUE-T ρ=0.57).
• Improved UE sensation, alongside motor scores, better predicted functional outcomes than motor scores alone. Rehabilitation alone yielded no sensory improvements.

Conclusions:

• Combined tSCS and rehabilitation therapy leads to widespread, clinically meaningful sensory improvements across multiple dermatomes in individuals with SCI.
• These sensory enhancements, coupled with strength gains, are vital for achieving significant functional recovery.
• tSCS represents a promising therapeutic approach for improving sensory function after spinal cord injury.