Pain, Spasticity and SCI
Many who have loved ones and friends in wheelchairs because of a spinal cord injury (SCI) are aware of the many associated complications that come along with living life day to day with paralysis. Those who are not close to someone living with paralysis may be surprised to learn that a large percentage live with spasticity, sudden involuntary muscular contractions, and uncontrollable and debilitating pain. Eva Widerström-Noga, D.D.S., Ph.D., Research Professor, Department of Neurological Surgery and Physical Medicine and Rehabilitation, and The Miami Project to Cure Paralysis at The University of Miami Miller School of Medicine, has spent most of her career studying the complex pain conditions that occur after injury but lately also looking at spasticity and how these common issues may be associated, and to try and develop solutions for the paralyzed dealing with these problems.
Three recent papers by Dr. Widerström-Noga, and colleagues, describe how Miami Project researchers are looking to increase our understanding of these two important topics affecting many living with SCI, and potential ways to help evaluate and alleviate the problem. The papers are: Spasticity and pain after spinal cord injury: Impact on daily life and the influence of psychological factors from the journal Physical Medicine and Rehabilitation, Impact of spasticity on transfers and activities of daily living in individuals with spinal cord injury from The Journal of Spinal Cord Medicine, Utility of the Neuropathic Pain Symptom Inventory in people with spinal cord injury from Spinal Cord.
“Every individual may experience multiple consequences after their SCI. Some of these are visible, like spasms, and some are invisible like pain. Although I have primarily studied pain after SCI, I know that pain is influenced by several other factors such as spasticity and psychosocial factors. Understanding how these factors influence each other is a step to better understand the clinical problem, and better the clinical treatment strategies,” said Dr. Widerström-Noga.
The Physical Medicine and Rehabilitation manuscript demonstrated that spasticity and chronic pain were strongly related to each other with respect to severity, difficulty dealing with, and interference with life. Shorter time since injury, greater severity of spasms, and having difficulty dealing with pain predicted having difficulty in dealing with spasticity. Greater severity of spasticity and lower resiliency (psychological strength) were associated with greater interference with life activities. Participants who experienced spasms that were painful, had more chronic pain and sleep interference than those who had spasms that were not painful. These relationships suggest that an assessment strategy that includes spasticity, pain and psychosocial factors may facilitate better management of these complex conditions.
Another of Dr. Widerstrom-Noga’s papers from The Journal of Spinal Cord Medicine, established that spasm duration and magnitude measured by electromyography and a clinical spasticity measure in the lower extremities of those living with SCI did not significantly determine how much spasticity impacted on daily life. However, quadriceps spasm duration during transfers is related to clinically-rated extensor spasticity. Future investigations should identify factors that influence the impact of spasticity on life, which may help direct treatment strategies to reduce problematic impact. In summary, although lower body spasms can be evaluated reliably with electromyographic assessments these measures are not necessarily indicating whether spasticity is perceived as a problem. Therefore, it is important to also identify individual factors that may contribute to problematic spasms to design strategies that target such factors.
Finally, on the neuropathic pain front, the paper in Spinal Cord on the Neuropathic Pain Symptom Inventory (NPSI) investigated a simple and quick method to determine the severity of different types of neuropathic pain symptoms specifically after SCI. There is a great deal of variability among people who experience these pain types after their injuries. Therefore, there is a need for valid and reliable methods to evaluate people with different neuropathic pain symptoms and severities. The study showed that the NPSI is a useful and quick way to evaluate both specific neuropathic pain symptoms and more complex subgroups of symptoms that can be used to tailor pain treatments.
“There is great variability in pain symptoms among people who experience SCI. This variability is to some extent related to underlying mechanisms and better treatments should ideally be tailored to these mechanisms. NPSI is an important but simple instrument that has the potential to provide a link between pain symptoms, mechanisms, and treatment. Therefore, we investigated the accuracy and reliability the NPSI to assess pain after SCI. Now when we have established the usefulness of the NPSI, we (and others) can use it to not only assess neuropathic pain symptom severity but also develop clinical trial designs to target pain mechanisms in people with SCI,” added Dr. Widerstrom-Noga.