Modification of phantom limb pain using a functional myoelectric prosthesis with sensory feedback

Status:

completed 04/2012

Aims:

Traumatic amputation of the upper extremity as a result of an accident often leads to chronic phantom pain. This phantom pain is difficult to treat with rather frustrating outcome. This project will change this situation. The project is based on considerations of cortical reorganization in the primary somatosensory cortex S1. Cortical reorganization might explain up to 90 % of phantom pain. The method used in this project is aimed to modify the central reorganization to reduce phantom pain by the use of a myoelectric hand prosthesis with somatosensory feedback.

Activities/Methods:

Magnetoencephalographic activities (MEG) and functional magnetic resonance imaging (fmRI) will be used to quantify use-dependent re-reorganization. A miniaturization of the feedback components of the myoelectric prosthesis will be developed. Use of prosthesis and acceptance will be assessed by the patients. Phantom limb pain will be assessed by different questionnaires. Correlation analysis will be performed with these data.

Results:

Reduction of phantom limb pain after two types of training, discrimination of electrocutaneous stimuli and prosthesis training has been shown in patients with upper limb amputation. The reduction of phantom limb pain was significantly higher for prosthesis training than discrimination training. During the training period, patients experienced the change in phantom limb pain as substantial. These results are in line with better mood and less somatic impairment due to training. Taken together, the effects of the prosthetic hand with somatosensory feedback can be interpreted as improvement in quality of life and are therefore substantial for social insurance companies. Importantly, the gain in functionality improves substantially, a fact that also leads to higher compliance of the patient. Patients also report on a significant gain in quality of the daily life with the new kind of prosthesis. Besides the reduction of phantom limb pain, cortical re-reorganisation has been shown in the expected direction. Furthermore, a therapeutic effect of a diagnostic axillary blockade of the brachial plexus on post-amputation symptoms (phantom pain, phantom sensations) has been shown.

Last Update: