Peripheral Modulation of Muscle Stiffness and Spasticity

Aim 1: To test the effect of hyaluronidase injections on upper limb motor outcomes; Aim 2: To
evaluate the effect of hyaluronidase injections on non-neural and neural components of muscle
stiffness; Aim 3. To determine the effect of hyaluronidase on intramuscular GAG content by
proton T1p relaxation mapping on muscle MRI.

Inclusion Criteria:

- ischemic or hemorrhagic stroke 6-36 months prior and radiologically verified;

- moderately-severe muscle stiffness, score of 2-3 on the Modified Ashworth Scale;

- lack of full passive and active range of motion in at least 2/4 areas (shoulder,
elbow, forearm, wrist) in the hemiparetic upper limb;

- willingness to have MRI, complete all clinical assessments, and comply with study
protocols;

- ability to give informed consent and HIPPA certifications; and

- Ability to communicate in English.

Exclusion Criteria:

- treatment of spasticity with Botulinum toxin or intrathecal baclofen within the past
three months;

- other neurologic condition that may affect motor response (e.g., Parkinson's disease,
ALS, MS);

- clinically significant cognitive dysfunction with score <24 on Folstein's Mini Mental
Status Examination or depression with score <10 on the PHQ-9;

- pregnancy;

- known hypersensitivity to hyaluronidase;

- claustrophobia;

- presence of pacemakers and clips that preclude MRI;

- contracture at any joint with Modified Ashworth Scale score = 4 and major disability
with modified Rankin Scale score ≥4; and

- History of psychiatric illness, complicated medical condition, or significant injury
to either upper limb.