The Role of Trans-spinal Direct Current Stimulation (tsDCS) in Treating Patients With Hand Spasticity After Stroke

Inclusion criteria

• First single focal unilateral hemisphere lesion with diagnosis verified by brain imaging (MRI or CT scans) that occurred at least 6 months prior
• Cognitive function sufficient to understand the experiments and follow instructions
• A Modified Ashworth Scale score between 1-3 points for wrist flexor and extensor muscles
• A minimum of 15 degrees wrist passive range of motion (ROM) for wrist flexion and extension from wrist neutral position

Exclusion criteria

• Focal brainstem or thalamic infarcts
• Prior surgical treatments for spasticity of the upper limb
• Ongoing use of central nervous system (CNS)-active medications
• Ongoing use of psychoactive medications, such as stimulants, antidepressants, and anti-psychotic medications
• Botox or phenol alcohol treatment within 12 weeks of enrollment
• Pregnancy in women, as determined by self-report
• History of spinal cord injury or weakness
• Chronic pain
• Peripheral neuropathy including insulin dependent diabetes as determined by case history
• Presence of additional potential tsDCS risk factors:

• Damaged skin at the site of stimulation (i.e., skin with ingrown hairs, acne, razor nicks, wounds that have not healed recent scar tissue, broken skin, etc.)
• Presence of an electrically, magnetically or mechanically activated implant (including cardiac pacemaker), an intracerebral vascular clip, or any other electrically sensitive support system
• Highly conductive metal in any part of the body, including metal injury to the eye (jewelry must be removed during stimulation)
• Past history of seizures or unexplained spells of loss of consciousness during the previous 36 months