1. A multi-modal medical device system that provides treatment therapy for a nervous system disorder, comprising: an implanted component that applies the treatment therapy and that supports a first feature associated with the treatment therapy; a first external component that shares data with the implanted component and that supports a second feature associated with the treatment therapy in accordance with the data; and a first communications channel that is optionally coupled to the implanted component and the external component, the data being transported over the communications channel, wherein the multi-modal medical device system continues to operate with the first feature when the external component is decoupled from the communications channel.