Maraviroc: Medications are often in flux during inpatient rehabilitation, so Maraviroc or placebo will be started within two weeks of discharge, which most often will occur from 4-6 weeks after stroke onset. A 1-month supply of capsules will be handed to participants after the Consent has been signed, baseline measurements obtained, and randomization assigned, usually on the same day. The second 1-mo supply will be provided during a scheduled interim measurement assessment at UCLA near the end of the 4th week on medication. Pill counts will be taken on the returned bottle. Participants will take either Maraviroc or a placebo at a dose of 300 mg at 6-8AM. The capsules will be supplied by the UCLA or Burke pharmacies and used under an IND and IRB protocol as required by each institution.