The efficacy of hybrid neuroprostheses in the rehabilitation of upper limb impairment after stroke, a systematic review with a meta-analysis

Abstract

Abstract Background. After stroke, paresis of the upper limb (UL) is the most frequent impairment. Hybrid neuroprostheses, i.e., the combination of robots and electrical stimulation, emerge as an option to treat these impairments. Methods. To give an overview on existing devices, their features and how they are linked to clinical metrics, four different databases were systematically searched for studies on hybrid neuroprostheses for the UL rehabilitation after stroke. The evidence on the efficacy of hybrid therapies was synthesized. Results. Seventy-three studies were identified, introducing 32 hybrid systems. Among the most recent devices (n = 20), most actively reinforce movement (3 passively) and are typical exoskeletons (3 end effectors). If classified according to the ICF, systems for proximal support are rather expected to affect body structures and functions, while the activity and participation level is targeted when applying FES distally plus the robotic component proximally. The meta-analysis reveals a significant positive effect on UL functions (p < .001), evident in a 7.8 point Mdiff between groups in the Fugl-Meyer assessment. This positive effect remains at 3-months follow-up (Mdiff=8.4, p < .001). Conclusions. Hybrid neuroprostheses have a positive effect on UL recovery after stroke, with effects persisting at least three months after the intervention. Non-significant studies were those with the shortest intervention periods and the oldest patients. Providentially, improvements in UL functions are not only present in the subacute phase after stroke, but also in long-term chronic stages. In addition to further technical development, more RCTs are needed to make assumptions about determinants of a successful therapy.