Proprioception, the sense of limb position and movement, is impaired in over 50% of stroke survivors. Proprioceptive impairments are known to impede motor recovery, yet proprioception is rarely a focus of stroke rehabilitation. One strategy aimed at facilitating proprioceptive recovery and/or compensation is to have patients look at their arms while performing tasks. We have previously shown that many stroke survivors cannot use vision to compensate for impaired proprioception at ~ 10 days post-stroke, but it is unknown if compensation occurs at later timepoints. We aimed to characterize performance of stroke survivors on a position sense task with and without vision of their limbs over the first 6 months post-stroke. We used a robotic exoskeleton to assess 89 stroke survivors at 2, 6, 12, and 26 weeks post-stroke on an arm position matching task, first without and then with vision of the upper limb. Three measures of position sense (Variability, Contraction/Expansion, and Shift) were used to classify participants into one of five groups: normal (unimpaired in both conditions), full compensation (impaired without vision, unimpaired with vision), partial compensation (impaired in both conditions but significantly improved with vision), absent compensation (impaired in both conditions and did not significantly improve with vision), and maladaptive compensation (unimpaired without vision but impaired with vision). Over time, all measures of position sense improved at a group level in both no vision and vision conditions. While more participants were able to compensate over time for proprioceptive deficits using vision, up to 26% of participants displayed absent or maladaptive compensation at 2 weeks post-stroke, and up to 11% of participants displayed these behaviours at 26 weeks post-stroke. Notably, at 26 weeks post-stroke, up to 22% of participants still had impaired task performance in both the no vision and vision conditions. Many stroke survivors could not use vision to compensate for proprioceptive deficits during the first 6 months post-stroke. This may be due to visual problems or issues integrating visual and proprioceptive information. Greater understanding of vision, proprioception, and their integration during the subacute phase of stroke is needed to target treatments to improve stroke recovery.
Kuhl et al. (Sat,) studied this question.