Evaluation of a Haptic Glove for Assessing Tactile Perception in Post-Stroke Patients

Sensory and proprioceptive deficits in the upper limbs affect about 50-85% of stroke survivors. These deficits can impact single sensations (such as primary tactile senses like light touch, pressure, and localization) and the ability to discriminate between different materials or temperatures, as well as proprioception and multiple somatosensory modalities. Furthermore, somatosensory deficits have been strongly correlated with variations in treatment responses among patients. However, in clinical practice, the use of appropriate quantitative tools to measure these deficits is not widespread, and evidence for active sensory training remains limited.

In recent years, robotic therapy has been proposed as an effective approach for upper limb rehabilitation. Nevertheless, recent studies with large samples have failed to demonstrate the superiority of robotic treatment over traditional methods regarding the recovery of upper limb motor functions. These studies primarily focus on motor aspects of stroke recovery, often neglecting sensory and cognitive aspects of rehabilitation, whether robotic or conventional.

Actually, there is limited evidence supporting the superiority of robotic approaches over conventional rehabilitation in recovering cognitive deficits and sensitivity. Additionally, it remains unclear whether cognitive and/or sensory deficits impact motor outcomes differently when using robotic versus conventional approaches.

To address this, the SCORES (Sensory and Cognitive Outcomes of Robotic Exercises in Stroke) study is a multicenter randomized controlled study investigating the effects of robotic rehabilitation on cognitive and sensory deficits in stroke survivors. It aims to compare robotic and conventional rehabilitation approaches regarding cognitive recovery and tactile sensitivity in subacute stroke patients. While some quantitative methods exist to assess absolute perception levels of tactile stimuli, standardized, repeatable, and objectively quantitative methods for assessing localization ability are lacking. Therefore, this study will evaluate how the tactile perceptual abilities of recruited patients evolve during and after a rehabilitation course-whether robotic or conventional-using a specifically developed haptic device that includes a glove with integrated vibrotactile elements. This system aims to objectively define patients' tactile sensitivity through psychophysical evaluations involving the identification and localization of randomized vibrations delivered to the surface of the hand affected by sensorimotor alterations. Specifically, this study will investigate the test-retest reliability, discriminant ability, responsiveness, and clinical validity of the metrics obtained from the haptic glove.

During each experimental session, randomized vibrotactile stimuli will be administered to the recruited patient at different sites on the hand. The patient will be asked to identify and verbally communicate the site of each perceived vibration, as well as the intensity of the vibration itself between the two possible levels.

• Number of stimulations provided by the haptic glove and correctly identified in terms of intensity and localization (test-retest reliability) [Time frame: Baseline; within two day after baseline]
• Number of stimulations correctly identified in terms of intensity and localization (responsiveness) [Time frame: Baseline; within 2 days after the end of rehabilitation treatment; 6 months after the end of treatment.]
• Number of stimulations correctly identified in terms of intensity and localization (clinical validity) [Time frame: Baseline; within 2 days after the end of rehabilitation treatment.]