Sildenafil and Stroke Recovery

Individuals who are within 4-10 days post ischemic stroke with arm hemiparesis or hemiplegia
who are admitted to inpatient rehabilitation are randomized to receive either sildenafil
citrate (25 mg once per day) or placebo for 14 days. These individuals receive usual
rehabilitation and medical care. Primary outcomes are motor skills and walking speed at one
and three months.

If willing and able, participants undergo an MRI to measure the integrity of the white
matter pathways in the motor system using diffusion tensor imaging. Repeat MRIs are obtained
at one and three months. The investigators will examine if such white matter integrity
predicts response to the drug and if the drug facilitates changes in white matter.

Inclusion Criteria:

1. between 4 and 9 days post-ischemic stroke;

2. admitted to inpatient rehabilitation;

3. cognitively able to provide consent or assent;

4. were living independently in the community prior to their stroke.

Exclusion Criteria:

1. hemorrhagic stroke or subarachnoid hemorrhage;

2. other neurological or psychiatric conditions deemed by the investigator to impair
participation;

3. no previous stroke on same side of brain unless that stroke was cerebellar

4. moribound or not expected to live 6 months;

5. contraindications to taking sildenafil in pill or syrup form;

6. other medical conditions that would limit ability to participate in the study,
specifically a) currently taking the P450 enzyme inhibitors (erythromycin,
ketoconazole, itraconazole, saquinavir), b) currently taking the protease inhibitor
ritonavir, c) currently taking nitrates or have a history of requiring nitrates
treatment, d) have left ventricular outflow obstruction (i.e., aortic stenosis,
idiopathic hypertrophic subaortic stenosis as confirmed by review of standard of care
echo received before admission to rehabilitation), e) have severely impaired
autonomic control of blood pressure, f) have previous history of symptomatic
hypotension, g) have severely impaired hepatic function, h) is pregnant or become
pregnant during the course of the study, i) Any medical condition which, in the
opinion of the investigator, may compromise compliance with the objectives and/or
procedures of the protocol.

7. scores > 50 on the upper extremity section of the Fugl-Meyer or no walking/gait
impairment

For the MRI portion of the study only:

8. contraindication to MRI: ferrous metal in body, lead included body art,
claustrophobia, pacemaker

9. allergic to or had previous reaction to gadolinium