The purpose of this study in people living with cervical Spinal Cord Injury (SCI) is to examine the effects of paired neurostimulation (i.e., PCMS) combined with contralateral motor training on inter-limb transfer of ballistic motor and hand dexterity skills.
Cervical spinal cord injury (SCI) is the most common and severe type of SCI that can lead to paralysis of the trunk and all four limbs, also known as tetraplegia. People with tetraplegia place a high priority on regaining upper limb motor function to be independent in daily life. Despite intensive therapies, upper limb motor gains are slow to emerge, especially in chronic cases. A critical barrier to effective and efficient upper limb rehabilitation in cervical SCI lies in the motor deficits of inter-limb transfer. Inter-limb transfer refers to a natural innate process within the human neuromotor system that motor skills acquired in one limb can transfer to the opposite, untrained limb, and is believed to play a key role in maximizing and accelerating post-injury recovery. Inter-limb transfer however is deficient following cervical SCI due to a breakdown of inter-limb neural connections at the cortical and spinal levels. Prior studies in uninjured people reveal that one can upregulate inter-limb neural mechanisms and hence augment inter-limb transfer effects by giving neurostimulation to augment corticomotoneuronal pathways to the untrained arm just before motor training in the contralateral arm. This study aims to rebuild inter-limb transfer of motor gains in chronic cervical SCI using a novel non-invasive neurostimulation method called paired corticospinal-motor neuronal stimulation (PCMS). We will test the central hypothesis that PCMS given to an untrained hand immediately before the visuomotor ballistic motor training at the other hand will improve inter-limb transfer of ballistic motor and dexterity skills to the untrained hand, based on potentiation of inter-limb neural mechanisms.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
SUPPORTIVE_CARE
Masking
SINGLE
Enrollment
17
PCMS + Contralateral Motor Training will involve delivering 360 pairs of TMS-PNS pulses (30min, 0.2 Hz) to the weaker first dorsal interosseous (FDI) muscle immediately before a session of ballistic index finger abduction training at the opposite, stronger FDI muscle.
PCMS + Rest will involve delivering 360 pairs of TMS-PNS pulses (30min, 0.2Hz) to the weaker FDI followed by a 30-min rest.
360 TMS pulses will be delivered at a location 10-cm posterior to the participant's head (into the air, 0.2Hz) and no PNS pulses will be generated, followed by a session of 30-min ballistic index finger abduction training at the opposite, stronger FDI muscle.
Lerner Research Institute; Cleveland Clinid Foundation
Cleveland, Ohio, United States
Change in ballistic acceleration
Participants perform 10 trials of ballistic index finger abduction with a accelerometer attached to index finger to capture the peak acceleration during the movement.
Time frame: Baseline to post paired TMS and PNS stimulation, assessed for approximately 4-6 hours
Change in excitability of cortical and corticospinal physiology and interhemispheric connections (TMS)
Transcranial magnetic stimulation will be used to test cortical output from both hemispheres and will be measured as motor evoked potentials(MEPS) of the First Dorsal Interosseous (FDI) muscle.
Time frame: Baseline to post paired TMS and PNS stimulation, assessed for approximately 4-6 hours
Change in excitability of spinal physiology (F-wave)
Peripheral Nerve stimulation will be performed to collect the spinal F-wave amplitude of the First Dorsal Interosseous (FDI) muscle.
Time frame: Baseline to post paired TMS and PNS stimulation, assessed for approximately 4-6 hours
Change in Nine Hole Peg Test (NHPT)
The NHPT is used to measure finger dexterity measured in time to complete the test or amount of pegs placed in 100 sec.
Time frame: Baseline to post paired TMS and PNS stimulation, assessed for approximately 4-6 hours
Change in finger velocity smoothness during NHPT
The investigator will calculate the index finger(2nd digit) velocity smoothness using the number of local maxima of frontal plane finger velocities during the peg transfer phase using kinematic sensors place on the fingers.
Time frame: Baseline to post paired TMS and PNS stimulation, assessed for approximately 4-6 hours
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