Fast Arm Motor Skill Training (FAST)

Fast Training Promotes Recovery of Arm Movements Post-stroke Via Cerebellar-mediated Anticipatory Feedforward Control

Every year, almost 800,000 people experience a stroke in the United States, which lead to upper-limb impairments, making recovery of motor function a priority in stroke rehabilitation. 1) The primary objective of this study is to determine whether fast arm movement training on a tracking task ("Speed-training"), in chronic stroke survivors with mild to moderate paresis, will generalize to improve arm function better than dose-equivalent accuracy training on the same task. 2) study the effect of intensive arm training on the recovery of anticipatory feedforward control. 3) Determine the involvement of cerebellar-cortical circuits in the recovery of arm movements due to speed training.

About 65% of stroke survivors experience long-term limitations in upper extremity (UE) functions. In particular, limitations in arm reaching movements are prominent and correlate strongly with patients' impairment levels. Because activities of daily living often involve the UEs, retraining reach and grasp skills is critical for return to a full quality-of-life. Yet, the training parameters required for effective rehabilitation of UE function are not known. Recent evidence suggests that high-speed movements during training are effective at improving arm movements in individuals with chronic stroke. Hence, fast movements generating large errors, would promote the restoration of the feedforward controllers and therefore improves arm movements and UE functions in individuals with chronic stroke. Because the cerebellum is involved in learning feedforward controllers from motor errors, the improvements would be proportional to the integrity of the cerebellar-cortical networks. A double-blind quasi-randomized controlled study will be carried out in chronic post-stroke survivors. Participants will be assigned to either the speed-bias training group or a dose equivalent accuracy-bias training group (control) and will receive 4 days of training over a 1week period by a trained Occupational or physical therapist. Behavioral, EMG, and MRI data will be acquired within two weeks before, 3 days post, and one month after intervention.

Stroke, Physical therapy, neurorehabilitation, motor function, neuroplasticity, neuroimaging, MRI, TDI, Hemiparesis, occupational therapy, patient focused, motor learning, motor control, skill acquisition, skill training, motor recovery, task-oriented training, task-specific training, arm function, upper extremity, arm therapy, physical rehabilitation, arm rehabilitation

Participants will perform 400 complex movements per day over 4 days over a one-week period. The task requires participants to navigate their hand through a "track" projected on the surface of a table with a width of 5cm. Participants receive adaptive score based on their movement time. .

The accuracy-biased group receives a dose equivalent intervention with a emphasize on accuracy. The width of the track projected on the table is narrower (less than 2cm) and the adaptive score received are based on their accuracy to say within the boundary of the track.

This intervention is based on recent body of evidence that high-speed movements during training are effective at improving arm movements in individuals with chronic stroke.Participants will be rewarded for movements performed within a short amount of time.

This is an observation-only group. The training received in this group will be dose equivalent to the active group.

Average movement smoothness for 30 planar reaching movements to target arrayed on a planar workspace. Smoothness is computed by number of peaks in hand tangential velocity profiles of arm-reaching movements.

The investigators will compute the "Fitts" slope between "index of difficulty" of reaching movements and movement time, for targets at 3 distances and of 4 diameters.

Average movement smoothness for 30 planar reaching movements to target arrayed on a planar workspace. Smoothness is computed by number of peaks in hand tangential velocity profiles of arm-reaching movements.

The investigators will compute the "Fitts" slope between "index of difficulty" of reaching movements and movement time, for targets at 3 distances and of 4 diameters.

Inclusion Criteria: At least 6 months following an ischemic supratentorial stroke At least 21 years of age Exhibit residual capability to move the paretic UE (Upper Extremity Fugl- Meyer motor score >20/66) Able to follow a 2-step command (8th item on the MMSE test) Able to perform an unassisted arm reach movement of 25 cm ahead of the body within 5 seconds with trunk restraint Exhibit no greater than mild/moderate spasticity as assessed with a Modified Ashworth Score < 3 Exclusion Criteria: any neurologic diagnoses other than stroke peripheral movement restrictions, such as neuropathy orthopedic disorders affecting the paretic UE severe pain or sensory/proprioceptive impairment in the more affected UE visual neglect (more than 4% of lines left uncrossed on Albert's test). had a stroke directly affecting the cerebellum any contra-indications to MRI scanning mostly resolved impairments with an Upper Extremity Fugl- Meyer motor score >58/66

Lang CE, Strube MJ, Bland MD, Waddell KJ, Cherry-Allen KM, Nudo RJ, Dromerick AW, Birkenmeier RL. Dose response of task-specific upper limb training in people at least 6 months poststroke: A phase II, single-blind, randomized, controlled trial. Ann Neurol. 2016 Sep;80(3):342-54. doi: 10.1002/ana.24734. Epub 2016 Aug 16.

Winstein C, Kim B, Kim S, Martinez C, Schweighofer N. Dosage Matters. Stroke. 2019 Jul;50(7):1831-1837. doi: 10.1161/STROKEAHA.118.023603. Epub 2019 Jun 5.

Park H, Kim S, Winstein CJ, Gordon J, Schweighofer N. Short-Duration and Intensive Training Improves Long-Term Reaching Performance in Individuals With Chronic Stroke. Neurorehabil Neural Repair. 2016 Jul;30(6):551-61. doi: 10.1177/1545968315606990. Epub 2015 Sep 24.

Kantak S, McGrath R, Zahedi N, Luchmee D. Behavioral and neurophysiological mechanisms underlying motor skill learning in patients with post-stroke hemiparesis. Clin Neurophysiol. 2018 Jan;129(1):1-12. doi: 10.1016/j.clinph.2017.10.010. Epub 2017 Nov 8.

Pantano P, Baron JC, Samson Y, Bousser MG, Derouesne C, Comar D. Crossed cerebellar diaschisis. Further studies. Brain. 1986 Aug;109 ( Pt 4):677-94. doi: 10.1093/brain/109.4.677.

Kawato M, Gomi H. A computational model of four regions of the cerebellum based on feedback-error learning. Biol Cybern. 1992;68(2):95-103. doi: 10.1007/BF00201431.

Gribble PL, Ostry DJ. Compensation for interaction torques during single- and multijoint limb movement. J Neurophysiol. 1999 Nov;82(5):2310-26. doi: 10.1152/jn.1999.82.5.2310.

Maeda RS, Cluff T, Gribble PL, Pruszynski JA. Feedforward and Feedback Control Share an Internal Model of the Arm's Dynamics. J Neurosci. 2018 Dec 5;38(49):10505-10514. doi: 10.1523/JNEUROSCI.1709-18.2018. Epub 2018 Oct 24.