Reaching Accuracy Assessment in Cerebellar Stroke using Virtual Reality
Khai Du1, Leonardo Benavides1, Emily Isenstein1, Duje Tadin1, Ania Busza1
1University of Rochester
Objective:
To investigate the application of virtual reality (VR) in the rapid quantification of reaching accuracy at the bedside for patients with cerebellar stroke (CS).
Background:
Dysmetria, the inability to measure distance in muscular tasks correctly, is a characteristic clinical feature of cerebellar injury. Even though dysmetria can be quickly detected during the neurological examination with the finger-to-nose test, objective quantification of reaching accuracy for clinical assessment is still lacking. Emerging VR technology, together with recent improvements in the hand-tracking feature, offers an opportunity to closely examine the speed, accuracy, and consistency of fine hand movements and proprioceptive function.
Design/Methods:

29 individuals (10 CS patients and 19 age-matched not-disabled controls) performed a task measuring reaching accuracy on the VR headset (Oculus Quest 2). 50% of the trials displayed a visible rendering of the hand as the participant reached for the target (visible hand condition), while the remaining 50% only showed the target being extinguished (invisible hand condition). Reaching error was calculated as the difference in degrees between where the fingertip passed the arch and where the target was positioned. 


Results:
Reaching error was higher in CS than in age-matched controls in both visible hand and invisible hand conditions. Reaching error was higher in the invisible hand condition than in the visible hand condition in both healthy controls and CS patients. Average time taken to perform each trial was higher in CS patients than in controls in both visible and invisible hand conditions.
Conclusions:
Reaching accuracy assessed by VR promises to be a non-invasive and rapid approach to quantifying fine motor functions in clinical settings. In addition, this device has the potential to be a useful supplemental technology in monitoring fine motor and proprioceptive functions during physical rehabilitation. Further studies are needed to examine quantitative changes in reaching accuracy during post-stroke progression.
10.1212/WNL.0000000000202405