Patients who complete study SPM-007 will be enrolled in this study at the time of the last visit of the preceding study. The assessments at the last visit of the preceding study will also be used as baseline measures for the current study. If the patient has previously discontinued SPM-007 and greater than 30 days have elapsed since the final visit in SPM-007, baseline measures for the current study will be repeated, and an interim medical history will be taken to assess whether any new medical conditions were diagnosed in the time between studies.