Does the Use of an Auditory Cue Facilitate the Motor Control and Contribute to the Rehabilitation of Upper Extremity Movements After Stroke

In stroke survivors, losing the use of one arm can have devastating effects on activities of daily living (Carod-Artal & Egido, 2009; Green & King, 2010). Therefore, much effort has been made to improve recovery through the use of techniques such as constraint-induced (CIT) (Wolf et al., 2010; Wolf et al., 2006) and robotic (Conroy et al., 2011; Lo et al., 2010) therapy where motor learning principles such as repetition, goal-setting, and task-specificity are maximized. Interestingly, when intensity is controlled, large-scale randomized controlled trials have not demonstrated comparative effectiveness for these newer techniques and systematic reviews are cautious in promoting any technique over another, leaving therapists with little concrete guidance (see Lo et al., 2010, for example). Another group of rehabilitation methods can be grouped under the term "external" stimulation and these include direct electrical (or magnetic) stimulation of the brain and muscle and indirect stimulation such as visual, haptic/somatosensory and, the focus of this paper, auditory stimulation, also known as auditory cueing. It should be noted, that review papers on upper extremity (UE) stroke rehabilitation do not tend to promote any of these stimulation methods and that auditory cueing is usually only discussed with reference to gait rehabilitation. Our purpose, here, is to address this situation by specifically considering auditory cueing in the context of upper-extremity rehabilitation.So, to return to our title question, does use of an auditory cue facilitate motor control and contribute to rehabilitation of upper extremity movements after stroke, we would reply yes with just a few exceptions. We will use a combination of our own research and selected experiments from others to provide principles that can guide therapists in the potential use of auditory cueing in upper-extremity rehabilitation. Our position stems from our 15-year research program of adding a rhythmic auditory cue to a bilateral training approach for individuals with upper extremity hemiparesis. We begin with a description of how we chose to use an auditory cue in the first place, a description of the training method in some detail and a review of key studies that indicate potential benefits of the combined bilateral and rhythmic auditory cueing approach. Subsequently, we dissect why, with whom and when the use of an auditory cue appears to work. Finally, we discuss our findings and conceptualization in relation to the music therapy techniques of Rhythmic Auditory Stimulation and Patterned Sensory Enhancement and propose future directions for research and practice.Genesis of Bilateral Arm Training and Rhythmic Auditory CueingIn 1996, a colleague mentioned that she was able to alter spatial but not temporal gait parameters in a stroke rehabilitation study. We immediately thought of external auditory cueing because of the prevailing work on rhythmic interlimb coordination using dynamic principles (see Kelso, 1995). Specifically, we reasoned that an external rhythmic auditory cue would (a) guide the placement of footfalls using a combination of active attentional and feedback processes as well as (b) utilize the possibility of passive entrainment from the dynamics of oscillating systems. We soon found that others had already tested the efficacy of this idea (e.g., Thaut, McIntosh, Rice, & Prassas, 1993) and initiated our own student-based pilot project comparing 6 weeks of gait training (3 3 week) with an auditory cue versus gait training without an auditory cue versus no gait training in chronic stroke survivors. The results were promising in that 4 out of 5 participants with the auditory cue durably increased their gait velocity and symmetry while two participants with only gait training temporarily increased their gait velocity only and two controls did not demonstrate change (Whitall, McCombe Waller, Gordes, et al., 2000). So how did we decide to also transfer this approach to the upper extremity? …