Transcutaneous Spinal Cord Stimulation for Spasticity in Primary Lateral Sclerosis: A Case Series

Primary lateral sclerosis (PLS), a neurodegenerative disease characterized by lower extremity spasticity, significantly impacts mobility and quality of life. Treatment options predominantly involve pharmacological interventions offering limited relief. Transcutaneous spinal cord stimulation (tSCS) reduces spasticity in persons with spinal cord injury and multiple sclerosis but has yet to be investigated as a nonpharmacological intervention in persons with PLS. This study described postintervention changes in lower extremity spasticity and functional mobility in a small cohort of persons with PLS following a single tSCS session.

Six participants with PLS received 30-minutes of tSCS with pre-post assessments and 24-hour postintervention follow-up. Spasticity outcomes included the Modified Ashworth Scale, deep tendon reflexes, and the Numerical Rating Scale. Functional mobility outcomes included the Tinetti Performance Oriented Mobility Assessment, 10-Meter Walk Test, and 6-Minute Walk Test.

Participants, positioned supine, received a 30-minute tSCS session. Electrodes were placed at T11-T12 and para-umbilically. tSCS was delivered at 50 Hz, 400 μs, and individualized amplitude.

No adverse events occurred. Modified Ashworth Scale and Tinetti Performance Oriented Mobility Assessment scores improved in all participants; Numerical Rating Scale scores improved in 5 of 6 participants. Changes in deep tendon reflexes, 6-Minute Walk Test, and 10-Meter Walk Test were variable.

A single 30-minute tSCS session was well tolerated in 6 participants with PLS. tSCS may be an effective intervention for spasticity reduction and functional mobility improvement in this population; however, larger controlled trials are needed to evaluate the effectiveness of tSCS and determine the clinical significance and generalizability of these findings.