Date Presented Accepted for AOTA INSPIRE 2021 but unable to be presented due to online event limitations.
Uncertain poststroke prognosis makes it difficult for OTs to develop personalized treatments for their patients. This study evaluated electroencephalography (EEG) as a predictor of individual response to a rehabilitation program. Results demonstrate the potential for EEG to predict patients’ responsiveness to an upper extremity intervention. These findings may promote individualized treatment and encourage a larger follow-up study.
Primary Author and Speaker: Amanda A. Vatinno
Contributing Authors: Christian Schranz, Viswanathan Ramakrishnan, and Na Jin Seo
PURPOSE: Uncertain prognosis presents a hurdle in developing personalized treatment plans for individual patients in occupational therapy. Initial neural function (i.e. pre-intervention) may predict upper extremity motor recovery (Stinear, 2010) because it facilitates neuroplastic changes necessary for motor recovery (Hosp & Luft, 2011) to occur. Thus, this study sought to determine whether baseline neural function measured using electroencephalography (EEG) may be associated with upper extremity motor recovery after completion of a therapy program. To provide a complete picture of neural function for upper extremity movement, we examined 3 different EEG variables, including connectivity, power, and event related potential.
DESIGN: This research was a retrospective analysis of data from a pilot randomized controlled trial involving 12 chronic stroke survivors (<6 months post-stroke) with moderate upper extremity impairment (Seo et al., 2019).
METHOD: Stroke survivors (>6 months post-stroke) were randomly assigned to one of two groups. Both groups wore a wristwatch during 2-week (6-session) goal-directed task-practice therapy. The watch delivered imperceptible vibrotactile stimulation for the treatment group and no vibration for the control group. The Box and Block Test (BBT) was obtained at baseline, and post-therapy. EEG was acquired before the first therapy session while participants performed a grip task with the paretic hand. The grip task was segmented into preparation (i.e. immediately prior to grip execution) and grip, each lasting one second. Average connectivity between the primary motor, premotor, and somatosensory cortices was calculated within the alpha and beta frequency bands in both the lesioned and non-lesioned hemispheres during preparation and grip. The association between baseline connectivity and change in BBT scores from baseline to post was examined in a multiple regression while controlling for group assignment.
RESULTS: Change in BBT scores was significantly associated with baseline connectivity in the alpha band within the non-lesioned hemisphere during preparation (r = -0.84, p = 0.04) and grip (r = -0.85, p = 0.03). In addition, there was a significant interaction between group and baseline connectivity in the beta band within the lesioned hemisphere during preparation (treatment group: r = -0.8, control group: r = 0.6, p = 0.02) and in the alpha band within the lesioned hemisphere during grip (treatment group r = -0.8, control group: r = 0.5, p = 0.03). Additional measures of connectivity, measures of power, and event related potential were not significant (p < 0.05).
CONCLUSION: Results showed that baseline EEG connectivity may explain variability in patients’ motor recovery following a therapy program, and may hold value in predicting individual patients’ responsiveness to a given intervention. Specifically, connectivity may hold greater predictive value for upper extremity treatment response than power and event related potential. These findings are in line with previous research that shows the execution of upper extremity motor movement involves the transfer of information between the sensory and motor brain regions (Ridding & Rothwell, 1999). Therefore, our findings extend upon this knowledge by suggesting the integrity of the communication between such areas, as measured by connectivity, may best indicate the patients’ potential for motor recovery and treatment response.
IMPACT STATEMENT: Occupational therapists may infer patients’ individual responses to an intervention based on examination of neural function measured using EEG. Better prognosis can guide therapists to develop personalized therapy and choose the maximally efficient course of treatment for their patients.
References
Stinear. (2010). Prediction of recovery of motor function after stroke [Rapid Review]. Lancet Neurology, 9, 1228-1232. https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(10)70247-7/fulltext
Hosp, J. A., & Luft, A. R. (2011). Cortical plasticity during motor learning and recovery after ischemic stroke. Neural Plasticity, 2011, 871296. https://doi.org/10.1155/2011/871296
Seo, N. J., Woodbury, M. L., Bonilha, L., Ramakrishnan, V., Kautz, S. A., Downey, R. J., Dellenbach, B. H. S., Lauer, A. W., Roark, C. M., Landers, L. E., Phillips, S. K., & Vatinno, A. A. (2019, Mar 1). TheraBracelet Stimulation During Task-Practice Therapy to Improve Upper Extremity Function After Stroke: A Pilot Randomized Controlled Study. Physical Therapy, 99(3), 319-328. https://doi.org/10.1093/ptj/pzy143
Ridding, M. C., & Rothwell, J. C. (1999, Jun). Afferent input and cortical organisation: a study with magnetic stimulation. Experimental Brain Research, 126(4), 536-544. http://www.ncbi.nlm.nih.gov/pubmed/10422717
