There are several reported challenges in neuroprosthesis use:
- There is a general perception within the clinical community that neuroprosthesis technology is not fully matured and the application of its use is labour intensive
- Patients and families have over expectations from assistive systems as aspirations and results do not match
- Acceptance of the device depends on the specific needs of the client
- Complicated by variety of age and lifestyle factors represented in patients with UE paralysis
- Complacent (feel comfortable, safe and happy with home and workplace adaptation and with attendant care)
- Waiting for cure (refuse any other intervention)
- Afraid of technology
- Degree of cognitive interaction they require – high levels of attention to their neuroprosthesis may interfere with social interaction
- Impact in clinical applications is limited
- Reasons for poor acceptance are that it can be technical, cultural and psychological
- FES technology requires intensive maintenance and skilled technician
- Found to be effective in hospitals with strong engineering support
- Attempts to simplify neuroprosthesis systems and reduce the system’s donning and doffing time resulted in less technical support needed but the devices then failed to address the needs of a wider population
- Inadequate reliability of use (breakage of wires, electrode failure, accidental damage)
- The grasping functions are robotic quality of stimulated motions and in order to design a more dexterous hand motion it would require a more complicated system
- Overall cosmetics of the device
- Implanted neuroprosthesis require additional surgery and it is recommended that tendon transfers be performed to augment the system
- Extensive training is required to learn how to use the device, which is expensive in terms of staffing and resources
- Efforts to increase reliability of system components, data on long-term reliability not yet available
- Simple systems for powered tenodesis grip for individual with lesions at C6 or lower have not been fully explored in deference to volitional tendon transfer surgery (Popovic et al. 2002; Triolo et al. 1996)
The use of neuroprosthesis whether implanted or surface electrodes appear to benefit persons with C5-C7 level tetraplegia. The studies consistently demonstrate improvements in pinch (lateral and palmar), grip strength, and ADL functioning and general satisfaction with the use of the device, although the study subject numbers are relatively small. Ongoing compliancy and use of the devices on a long-term basis continue to be problematic. Reasons for discontinuing the use of the device are with length of time and the amount of assistance required to don and doff the device, and if using the device can provide enough of a difference in overall level of functioning. The studies also consistently report both mechanical/electrode failure and adverse medical complications. Many of the devices are only available in specialized rehabilitation centres where access to rehabilitation engineering is available. In addition, many of the devices continue to be only available in clinical trials. The overall cost to use the device continues to be great when factors such as cost of the device, the extensive training period required and staff to support the programme. The next generation of implantable FES devices are being developed at the FES Centre in Cleveland, OHIO and The Shriner’s Hospital, Philadelphia, Pennsylvania. These are internally powered and wirelessly control, eliminating an external coil and control unit. Also, in Alberta, Canada the ReJoyce System by Prochazka et al. (1997) a surface FES system and the Stimulus Router System (SRS) is being tested and further developed.
There is level 4 evidence (see Table 19-26) that support the use of neuroprostheses for persons with C5-C6 complete tetraplegia in the improvement of pinch and grip strength and ADL functioning. However, many devices are only available in clinical trials in specialized rehabilitation centres and the overall cost of the device continues to be expensive.
The use of neuroprostheses appears to have a positive impact on pinch and grip strength and ADL functions in C5-C6 complete tetraplegia, however, access to the devices are limited and continue to be expensive in use.