So cherry picking participants. I would completely fail at this test due to spasticity and the inability to open the hand.
Efficacy of interactive manual dexterity training after stroke: a pilot single-blinded randomized controlled trial
Journal of NeuroEngineering and Rehabilitation volume 20, Article number: 93 (2023)
Abstract
Objective
To compare the efficacy of Dextrain Manipulandum™ training of dexterity components such as force control and independent finger movements, to dose-matched conventional therapy (CT) post-stroke.
Methods
A prospective, single-blind, pilot randomized clinical trial was conducted. Chronic-phase post-stroke patients with mild-to-moderate dexterity impairment (Box and Block Test (BBT) > 1) received 12 sessions of Dextrain or CT. Blinded measures were obtained before and after training and at 3-months follow-up. Primary outcome was BBT-change (after–before training). Secondary outcomes included changes in motor impairments, activity limitations and dexterity components. Corticospinal excitability and short intracortical inhibition (SICI) were measured using transcranial magnetic stimulation.
Results
BBT-change after training did not differ between the Dextrain (N = 21) vs CT group (N = 21) (median [IQR] = 5[2–7] vs 4[2–7], respectively; P = 0.36). Gains in BBT were maintained at the 3-month post-training follow-up, with a non-significant trend for enhanced BBT-change in the Dextrain group (median [IQR] = 3[− 1–7.0], P = 0.06). Several secondary outcomes showed significantly larger changes in the Dextrain group: finger tracking precision (mean ± SD = 0.3 ± 0.3N vs − 0.1 ± 0.33N; P < 0.0018), independent finger movements (34.7 ± 25.1 ms vs 7.7 ± 18.5 ms, P = 0.02) and maximal finger tapping speed (8.4 ± 7.1 vs 4.5 ± 4.9, P = 0.045). At follow-up, Dextrain group showed significantly greater improvement in Motor Activity Log (median/IQR = 0.7/0.2–0.8 vs 0.2/0.1–0.6, P = 0.05). Across both groups SICI increased in patients with greater BBT-change (Rho = 0.80, P = 0.006). Comparing Dextrain subgroups with maximal grip force higher/lower than median (61.2%), BBT-change was significantly larger in patients with low vs high grip force (7.5 ± 5.6 vs 2.9 ± 2.8; respectively, P = 0.015).
Conclusions
Although immediate improvements in gross dexterity post-stroke did not significantly differ between Dextrain training and CT, our findings suggest that Dextrain enhances recovery of several dexterity components and reported hand-use, particularly when motor impairment is moderate (low initial grip force). Findings need to be confirmed in a larger trial.
Trial registration ClinicalTrials.gov NCT03934073 (retrospectively registered)
Introduction
Despite spontaneous recovery with conventional rehabilitation, over half of stroke survivors may retain a disabling motor deficit in the chronic phase, mainly affecting the upper limb [1, 2]. Although impaired manual dexterity and control of the fingers hamper many daily activities, there are currently no specifically targeted treatments for multiple aspects of dexterous manual control. Independent finger movements, a hallmark of manual dexterity in humans [3], is slow to recover after stroke [4]. Recovery of strength and finger individuation partly dissociate during the first 3-months, suggesting separate neural mechanisms driving their recovery [5]. In agreement, our team [6] showed that recovery of finger individuation during the first 6 months post-stroke was slower than that of grip force, and remained significantly impaired despite recovery in corticospinal excitability probed with transcranial magnetic stimulation (TMS). In the chronic phase, impaired strength and finger individuation together best explain impaired dexterous hand use, highlighting that both are essential to recover a functional hand [7]. Other aspects of manual dexterity, such as coordination of finger force in precision grip [8] or the capacity to release grip force abruptly (reflecting motor inhibition) [9], also remain particularly impaired in many chronic stroke survivors and contribute to deficient dexterous hand use.
A recent study reported that training of finger individuation in chronic stroke patients is feasible and can improve finger individuation and lead to lasting improvements in hand function [10]. Training of controlled index finger movements in the chronic post-stroke phase also leads to partially recovered dexterous hand use and is accompanied by reorganization of cortical sensorimotor networks [11]. Friedman et al. [12] showed enhanced recovery of dexterous hand use after MusicGlove training, and piano training may improve motor recovery of individuated finger movements [13]. However, randomized controlled trials are lacking and it remains therefore unclear whether finger-training approaches have enhanced efficacy to improve hand motor impairments and activity limitations compared to conventional therapy.
We have developed dedicated technology to simultaneously measure dexterity components and rehabilitate selective finger movement control [14]. The Dextrain Manipulandum™ allows measurement of flexion–extension finger movements. Finger movement tasks combine visual and auditory feedback, with each task targeting a previously identified specific dexterity component [14]. The four principal exercises include: (i) visuo-motor force-tracking focusing on generation, modulation and inhibition of finger forces; (ii) rhythm tapping for assessing timing of finger movements; (iii) motor sequences for evaluating reproduction and learning of sequential finger movements; and (iv) multi-finger tapping for quantifying finger individuation [6, 14]. This method was shown to be feasible in patients with mild-moderate upper limb impairment, and initial results confirmed differential recovery patterns among dexterity components [6, 14].
The present study aimed to evaluate the “proof-of-concept” benefit of training using the Dextrain Manipulandum for the rehabilitation of hand and fingers in stroke subjects. We hypothesized that training of specific finger dexterity components (e.g., force control and independence of finger movements) coupled with real-time visual feedback and performance scores, enhancing motivation, would lead to greater gains in dexterous hand use compared to dose-matched conventional therapy. A secondary aim was to investigate whether Dextrain therapy leads to greater improvements in hand motor and sensory impairments, quantified dexterity components and activity limitations, as compared to conventional therapy. Finally, to decipher the neurophysiological mechanisms underlying dexterity recovery we explored how motor cortex excitability and short intracortical inhibition (SICI), measured with TMS, changed with therapy and how this change correlated with dexterity improvements.
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