Neurostimulation in rehabilitation
This study will be performed at UT Southwestern Medical Center (UTSW), Parkland Health and amp; Hospital system (PHHS) and University of Texas at Dallas (UTD). The follow-up testing with TMS will be performed either at UTSW or at University of Texas at Dallas. The total expected recruitment will be 60 based on the inclusion and exclusion criteria.This study will enroll patients as well as normal ,healthy volunteers
Subjects will receive one or more of the following types of stimulation alone or in combination: (1) 1 Hz TMS for up to 30 minutes and up to 115% of resting motor threshold intensity (MT) (2) TBS below 100% active MT, (3) tDCS up to 2 mA for up to 60mins. (4) PNS with intensities below 130% of the peripherally-elicited-motor-threshold for up to 2 hours. Sham stimulations will be delivered for each modality.
Each subject may undergo up to 20 sessions spaced by at least one day and we will test the effects of these different forms of stimulation on motor cortical excitability, simple motor tasks. To identify the possible contribution of sub-cortical structures, we will also measure M-wave, F-wave, and/or H-Reflexes.
All experimental sessions will proceed with approximately the same schedule. Initially, electrodes will be placed over the target peripheral nerve(s) (I.e. median, ulnar or radial nerve) for peripheral nerve stimulation or different scalp positions for tDCS and over the specific muscle bellies from where motor evoked potentials will be recorded. The optimal target position for tDCS, TMS or TBS stimulation will be identified physiologically in most cases but in some individuals MRI-guided frameless stereotactic techniques will be used to determine optimal target position. Depending on the particular stimulating parameters, we will utilize peripheral nerve stimulation alone, cortical stimulation alone or a combination of both.A maximum of 2 forms of simultaneous-stimulation will be combined during any one session.
We will then proceed to determine baseline motor cortical excitability using single and paired pulse TMS. Application of central and/or peripheral nerve stimulation will be followed by post stimulation testing of motor cortical excitability. The whole procedure will last less than 4 hours.
1. We will include English speaking patients of all races/ethnicity, aged 18 to 80 years old who experienced, subcortical or cortical symptomatic strokes more than 3 months prior to the enrollment into this study with arm weakness (defined as MRC wrist/hand component 1 or more) Assessment of the initial functional state will be taken at initial evaluation.
2. For healthy volunteers, we will include subjects aged 18 to 80 years with normal
physical and neurological examination with clearly dominant handedness (right or left) as assessed by handedness scale