Patients routinely undergo deep brain stimulation (DBS) for treatment of symptoms related to neurodegenerative conditions, most commonly Parkinson's disease. In the Investigator's experience, and published evidence shows, that stimulation has effects on the autonomic nervous system. In patients undergoing therapeutic DBS for a particular subtype of Parkinsonism (Multiple System Atrophy), the effects on autonomic parameters such as blood pressure and bladder symptoms has been shown to be improved by the investigators (unpublished data). In this current study, the investigators plan to use a novel technique of adaptive DBS in order to provide stimulation dependent on patient physiological or positional factors. This is with the aim of making stimulation more responsive and patient-specific.