Objectively measuring pain

Dishman to test technology for use after strokes

Stroke, for example, hinders many patients’ ability to speak. To help assess their pain, Cizik School of Nursing at UT Health Houston Assistant Professor Deniz Dishman, PhD, CRNA, NSPM-C, is exploring a new technology with the aim of developing an objective way to measure pain that isn’t dependent on self-reported scales. She will use a $62,667 grant from the American Association of Nurse Anesthesiology Foundation for her study, “Calculating Objective Measures of Pain After Stroke?(COMPAS).”

Poststroke pain is quite common and if untreated can present a major barrier to critical rehabilitation programs and lead to loss of function, worsened depression, cognitive decline, and increased risk of subsequent strokes.

The COMPAS trial focuses on detecting and measuring responses to nociception in a cohort of stroke survivors. Nociceptors are sensory receptors activated by noxious stimuli when the body is injured or harmed, and nociception is the process by which those signals are processed and received by the central nervous system.

The Nociceptive Level (NOL) index™ was developed for use with a physiological monitoring system that detects responses to nociception. Sensors in a finger probe measure variations in pulse, body movement, and the temperature and electrical conduction of the skin. The system was originally intended to gauge nociception in patients under general anesthesia for surgical procedures, but Dishman sees potential in using it with patients who have experienced stroke.

“More than a third of stroke survivors suffer cognitive impairment and/or an expressive disability that render self-report pain scales useless,” said Dishman, who leads UTHealth Houston’s Pain Management Program at the Institute for Stroke and Cerebrovascular Disease. “Identifying pain in those with communication disabilities would enable equitable access to care for stroke survivors and others who cannot express their needs.”

The first step is to apply NOL technology to stroke survivors who can communicate. Dishman’s team will recruit 52 stroke survivors to compare self-reported pain to responses detected by the NOL index.

“Developing noninvasive, objective, continuous pain measures will change current treatment paradigms, particularly for those with neurologic injury, cognitive impairment, and/or the inability to communicate and therefore are unable to self-report pain,” Dishman said. “Objective pain measures will also facilitate the discovery of effective pain interventions now absent in treatment models.” 

In addition to benefiting stroke survivors, new methods of objective pain assessment hold potential for helping patients experiencing traumatic brain injury, Alzheimer’s disease, dementia, substance abuse disorder, and other conditions that hinder communication.

Two faculty members from McGovern Medical School at UTHealth Houston serve as Dishman’s co-investigators on the COMPAS trial: Professor Sean Savitz, MD, the Frank M. Yatsu Chair in Neurology and director of the Institute for Stroke and Cerebrovascular Disease at UTHealth Houston; and Associate Professor Charles Green, PhD, who is faculty in the Department of Pediatrics and the Center for Clinical Research and Evidence Based Medicine at UTHealth Houston.

Dishman is also conducting research investigating brain mapping of patients with poststroke shoulder pain using electroencephalographic imaging and functional MRIs. That study, “Biomarkers Illuminating Pain After Stroke (BIPAS),” is a collaboration with Savitz, Green, Sarah Prinsloo, PhD, from The University of Texas MD Anderson Cancer Center, and Professor Xiaoqian Jiang, PhD, the center director of Secure Artificial intelligence For hEalthcare (SAFE) at the McWilliams School of Biomedical Informatics at UTHealth Houston. This project is funded by a generous $100,000 PARTNERS Nursing Research Award.