Guanfacine for the Treatment of Spatial Neglect and Impaired Vigilance

Inclusion Criteria: * Age 18 or more * Greater than 2 weeks following stroke * Ability to give consent * Evidence of robust Visual Neglect when tested twice with cancellation tasks. Exclusion Criteria: * Less than 2 weeks following stroke * Concomitant illness that may affect interpretation of any findings * Labile blood pressure following stroke * Systolic BP less than 100 mmHg and / or diastolic less than 70 mmHg * New antihypertensive medication started within last 3 weeks * Patients with hepatic or renal dysfunction * Patients receiving other medications known to potentiate guanfacine's antihypertensive and hypotensive effects or cause torsade de pointes, specifically antipsychotics (including sultopride, chlorpromazine, thioridazine, amisulpiride, sulpiride, haloperidol), and moxifloxacin, baclofen, verapamil, quinidine, hydroquinidine, dispyramide, amiodarone, dofetilide, ibutilide, sotalol, pimozide, bepridil, cisapride, diphemanil, erythromycin IV, halofantrine, pentamidine, sparfloxacin, vincamine, alfuzosin, prazosin, terazosin, tamsulosin, amifostine * Patients with diagnosis of brain tumour * Patients with weight less than 55kg * Patients who are pregnant * Mothers who are breast feeding * Patients with severe coronary insufficiency or myocardial infarction in previous 6 months * Cognitive impairment, dysphasia or dementia that prevents patient from giving informed consent * Severe mental impairment or physical handicap following stroke that prevents patients from giving consent or performing basic (standard clinical) tests for neglect