Two week up-titration to reach a total dose of 20mg per oral four times per day over the first two weeks then will remain on a stable dose for six weeks. The patients will be treated for eight weeks, complete a one week washout and then crossed over to another arm for eight weeks.

Identical placebo. The patients will be treated for eight weeks, complete a one week washout and then crossed over to another arm for eight weeks.

Propranolol is started 10 mg tablet twice per day per oral, two week up-titration to reach a total dose of 20mg per oral four times per day over the first two weeks, then will remain on a stable dose for six weeks.

AIMS is a rating scale that scores each individual involuntary movement type at different body locations on a five-point anchored scale. For this study, items 1-7 represent the severity portion (rated 0-4) of the scale and will be used as the primary end point. This measure will be completed at the time of the visit by the enrolling physician. In addition, a standardized video documenting the motor portion of the AIMS will be completed at baseline and eight weeks for both segments of the study. These will be placed in a randomized order and scored using the AIMS severity scale by two blinded raters using consensus measures. A comparison of the change in score from placebo to active by the blinded video raters will be the primary outcome measure.

The CGI provides an overall clinician-determined summary measure that takes into account all available information, including a knowledge of the patient's history, psychosocial circumstances, symptoms, behavior, and the impact of the symptoms on the patient's ability to function.

The CGI-Severity (CGI-S) asks the clinician one question: "Considering your total clinical experience with this particular population, how mentally ill is the patient at this time?" which is rated on the following seven-point scale: 1=normal, not at all ill; 2=borderline mentally ill; 3=mildly ill; 4=moderately ill; 5=markedly ill; 6=severely ill; 7=among the most extremely ill patients.

This rating is based upon observed and reported symptoms, behavior, and function in the past seven days. As symptoms and behavior can fluctuate over a week; the score should reflect the average severity level across the seven days.

The Short Form-36 question health survey (SF-36v2) measures a subject's functional health and well-being from their own point of view. SF-36v2 is comprised of 36 questions spanning eight health domains: physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health. The eight scaled scores are the weighted sums of the questions in their section. Each scale is directly transformed into a 0-100 scale on the assumption that each question carries equal weight. The lower the score the more disability. The higher the score the less disability i.e., a score of zero is equivalent to maximum disability and a score of 100 is equivalent to no disability. The health domain scales contribute to the scoring of two summary measures: physical health and mental health.