Dr. Thomas Publishes a Paper Linking Involuntary Muscle Contractions after SCI to Self-reported Spasticity

Dr. Christine Thomas Publishes a Paper that links the characteristics of Involuntary Muscle Contractions after Spinal Cord Injury to Self-reported Measures of Spasticity

Christine K. Thomas, Ph.D., Professor, Department of Neurological Surgery and The Miami Project recently published a paper in Frontiers in Neuroscience titled Characterization of Involuntary Contractions after Spinal Cord Injury Reveals Associations between Physiological and Self-Reported Measures of Spasticity.

Spasticity is common after spinal cord injury with about half of injured people who experience the increases in muscle tone and reflexes, as well as muscle spasms, find it problematic. It has been difficult to quantify because only weak associations exist between clinical, physiological, and self-reported measures of spasticity. This study examined relationships between self-report of muscle spasms, physiological spasticity assessments, and involuntary muscle activity (muscle spasms) generated during a typical daily task – a transfer from wheelchair to bed – because people with spinal cord injury often describe their spasms when asked.

Dr. Thomas and her team found that strong, short duration muscle spasms during transfers were related to high self-reported spasm frequency, suggesting that injured individuals use the length of the contractions to count spasms. Stronger spasms in all leg muscles, especially in quadriceps versus hamstrings muscles, and ankle flexors versus extensors, were correlated with greater overall spasm severity, which likely results in movement of the legs. Even though the team’s physiological measurements were not significantly related to the self-reported spasticity, their physiological measurements of both spinal inhibition and motoneuron excitability were related to the duration of the spasms.

This study is the first to provide evidence of a link between physiological assessments of spasticity and the duration and intensity of the muscle spasms that people experience. These results also suggest movement of the legs due to the spasms likely plays a large role in how people judge spastic activity.