Sonification of Arm Movements in Stroke Rehabilitation – A Novel Approach in Neurologic Music Therapy

This has been out there for years. When will the presidents of our fucking failures of stroke associations read the riot act to researchers that duplicate previous research and don't write up stroke protocols?

Interactive Sonification of Human Movements for Stroke Rehabilitation  May, 2012 

Approaching a new stroke rehabilitation therapy with a SonicPainter  Nov. 2013

A mobile sonification system for stroke rehabilitation  July, 2014 

Sonification as a possible stroke rehabilitation strategy  Oct. 2014 

Moving with music for stroke rehabilitation: a sonification feasibility study  March 2015 

The latest here:

Sonification of Arm Movements in Stroke Rehabilitation – A Novel Approach in Neurologic Music Therapy

Daniel S. Scholz¹, Sönke Rohde¹, Nikou Nikmaram¹, Hans-Peter Brückner¹, Michael Großbach¹, Jens D. Rollnik² and Eckart O. Altenmüller¹*

• ¹Institute of Music Physiology and Musicians’ Medicine, University of Music, Drama and Media, Hannover, Germany
• ²Institute for Neurorehabilitational Research (InFo), BDH-Clinic Hessisch Oldendorf, Teaching Hospital of Hannover Medical School (MHH), Hessisch Oldendorf, Germany

Gross motor impairments are common after stroke, but efficient and motivating therapies for these impairments are scarce. We present an innovative musical sonification therapy, especially designed to retrain patients’ gross motor functions. Sonification should motivate patients and provide additional sensory input informing about relative limb position. Twenty-five stroke patients were included in a clinical pre–post study and took part in the sonification training. The patients’ upper extremity functions, their psychological states, and their arm movement smoothness were assessed pre and post training. Patients were randomly assigned to either of two groups. Both groups received an average of 10 days (M = 9.88; SD = 2.03; 30 min/day) of musical sonification therapy [music group (MG)] or a sham sonification movement training [control group (CG)], respectively. The only difference between the two protocols was that in the CG no sound was played back during training. In the beginning, patients explored the acoustic effects of their arm movements in space. At the end of the training, the patients played simple melodies by coordinated arm movements. The 15 patients in the MG showed significantly reduced joint pain (F = 19.96, p < 0.001) in the Fugl–Meyer assessment after training. They also reported a trend to have improved hand function in the stroke impact scale as compared to the CG. Movement smoothness at day 1, day 5, and the last day of the intervention was compared in MG patients and found to be significantly better after the therapy. Taken together, musical sonification may be a promising therapy for motor impairments after stroke, but further research is required since estimated effect sizes point to moderate treatment outcomes.

Introduction

Stroke is a major cause of mortality and morbidity in both the developed and developing world (1). In Germany, stroke is one of the most common disorders with an estimated 200,000 first events and 66,000 recurrent events in 2008 (2). The World Health Organization stresses the need to collect high quality longitudinal data on rehabilitation and to improve the comparability between studies (3).

The rehabilitation of stroke patients remains a challenge, although there are currently several new training programs under development that aim at improved efficiency and sustainability of stroke rehabilitation (4). Some of the traditional rehabilitation programs lack general acceptance by patients, due to the required endurance and high demands on the patients’ cooperation, which sometimes is perceived as a frustrating experience (5). Yet, even the well-established standard physiotherapies do not unambiguously provide evidence of efficacy when it comes to improvement of skilled motor behavior (6–8). Therefore, there is an urgent need for innovative, motivating, and goal-directed training protocols in stroke rehabilitation.

In this article, we present an innovative approach to rehabilitation by retraining the gross motor functions of the affected upper limbs using musical sonification. In an earlier clinical feasibility study (9), we showed how a musical sonification therapy could be applied. The data presented herein were obtained with this method from a larger number of patients. Sonification stands for the usage of non-speech sound representing otherwise not audible information (10). One of the first sonification devices was the Geiger–Müller counter, which detects electromagnetic radiation and communicates a decay by a click sound. In the present study, arm movements were translated into sound. In two earlier studies, we demonstrated the efficacy of a music-supported stroke rehabilitation training utilizing a MIDI drumset and a MIDI piano (11, 12). Stroke patients with some residual abilities to move the arm and the fingers were instructed to play simple tunes (nursery rhymes or folk songs) on either instrument. We could show that auditory sensorimotor circuits established via this form of music-supported therapy (MST) promotes beneficial neuroplasticity in stroke patients (13, 14). One of the few constraints of MST was that it was mainly designed to retrain fine-motor skills on MIDI instruments. And it did not provide continuous real-time feedback for the gross motor functions of the arm, which are more frequently impaired in early rehabilitation stages. A real-time movement feedback may be beneficial since it informs the patients about the way they move, not only whether they hit the target or not. With the musical sonification therapy presented here, patients repeatedly train movements with their affected arm in a predefined space. They form associations of their relative armposition in space and the corresponding sound at this specific position. At the end, they play familiar melodies by moving their arm. This musical sonification therapy, therefore, broadens the scope to train stroke patients from an earlier stage on, when still suffering from gross motor dysfunction. Musical sonification will not only contribute to the motivation of the patients due to its playful and positive emotional character, but may also improve motor control, since auditory real-time feedback of the patient’s arm movements can be substituted for potentially lost proprioception. There are several preliminary studies with healthy participants that apply non-musical sonification in motor control and the perception of movements (15–17). Schmitz et al. found that sonifying breast stroke movements led to more precise perceptual judgments of movement velocity. They showed that sonification of movements amplifies the human action observation system as indicated by more pronounced fMRI connectivity patterns between the activation peaks of the left superior and medial posterior temporal regions with the basal ganglia, the thalamus, and frontal regions for movement congruent sonification stimuli. Thus, sonification may be an important method to enhance training and therapy effects in neurological rehabilitation. Chen et al. developed a real-time, multimodal feedback system for stroke rehabilitation (18). This sonification system was tested with stroke patients and showed promising results (19). However, in their design, music was only a passive byproduct of arm movements. That means participants did not play with the sonification sound intentionally. They moved their arms and harmonic music progressions were played back to them. In contrast to that, we developed a musical sonification therapy to train stroke patients to explicitly and consciously play music through intended movements of their affected upper extremity. Thus, we hoped to be able to use the beneficial effects of music on neuroplasticity to facilitate the recovery after stroke (13). Since in other studies repetitive exercise has been shown to be effective (8, 20), our training is of a repetitive nature too. We hypothesize that the auditory cues provided by the sonification may make multimodal associative learning possible where otherwise mere visual and motor learning would have taken place. We assume that patients will benefit in their rehabilitation process from guided attention, necessary concentration, and long-term motivation to play music. Rohrer et al. (21) (see also references therein) describe an increase of several movement smoothness indices in both acute and chronic stroke patients during movement therapy. Hence, the present study additionally investigated changes in movement smoothness over the course of the therapy. After having evaluated an optimal two-dimensional sonification mapping (22), we now present a more detailed analysis of our three-dimensional musical sonification therapy with a larger sample (9).