- Subjects who are unable to discontinue prohibited medications prior to sleep study and 1H-MRS. These include any CNS-active medications. For RLS subjects, RLS-related medications (e.g. dopaminergic agents and alpha 2-delta agents) must be discontinued a minimum of 48 hours prior to PSG. In the RLS group, benzodiazepines must be discontinued a minimum of one week prior to PSG. For normal controls with regular treatment (>1 time/wk) with CNS active agents within 1 month of screening visit will also be excluded.