Effect of robotic tilt table verticalization on recovery in patients with disorders of consciousness: a randomized controlled trial

Verticalization is a common therapeutic intervention during rehabilitation of patients with disorders of consciousness (DoC). The Erigo®Pro is a robotic tilt-table (RTT) with built-in stepping unit for the lower extremities to prevent orthostatic hypotension during verticalization. In addition, the system also provides functional electrical stimulation (FES) of muscles of the lower extremities. In this randomized controlled clinical trial (RCT), 47 patients with subacute DoC received a 4-week verticalization regime (16 verticalization sessions) and were allocated to one of three experimental groups: (1) verticalization by means of RTT with FES, (2) by means of RTT without FES, or (3) by conventional physiotherapy (CPT). Level of consciousness (LoC), spasticity, functional independence in daily activities, and functional brain connectivity measured by means of high-density quantitative EEG were assessed at baseline, directly after the verticalization program and after 6 months. There was a similar clinical improvement in all three experimental groups. RTT was not associated with an effect on any of the clinical outcomes. Verticalization or mobilization time during the study period was significantly positively correlated with recovery of consciousness (rho = 0.494, p < 0.001) in the short term and showed a statistical trend at the 6 months follow-up (rho = 0.244, p = 0.078). In conclusion, RTT treatment is not more effective in promoting recovery of consciousness than CPT in subacute DoC patients. Yet, our data suggest, that verticalization may be an important and feasible rehabilitation intervention in this group of patients. ClinicalTrials.gov NCT Number NCT02639481, registered on December 24, 2015.

The human egomotion network

All volitional movement in a three-dimensional space requires multisensory integration, in particular of visual and vestibular signals. Where and how the human brain processes and integrates self-motion signals remains enigmatic. Here, we applied visual and vestibular self-motion stimulation using fast and precise whole-brain neuroimaging to delineate and characterize the entire cortical and subcortical egomotion network in a substantial cohort (n=131). Our results identify a core egomotion network consisting of areas in the cingulate sulcus (CSv, PcM/pCi), the cerebellum (uvula), and the temporo-parietal cortex including area VPS and an unnamed region in the supramarginal gyrus. Based on its cerebral connectivity pattern and anatomical localization, we propose that this region represents the human homologue of macaque area 7a. Whole-brain connectivity and gradient analyses imply an essential role of the connections between the cingulate sulcus and the cerebellar uvula in egomotion perception. This could be via feedback loops involved updating visuo-spatial and vestibular information. The unique functional connectivity patterns of PcM/pCi hint at central role in multisensory integration essential for the perception of self-referential spatial awareness. All cortical egomotion hubs showed modular functional connectivity with other visual, vestibular, somatosensory and higher order motor areas, underlining their mutual function in general sensorimotor integration.