The overall objective of this study is to develop a psychometrically sound Health Related Quality of Life (HRQL) measurement tool that is accepted by the neurology clinical trials and clinical research communities.   Specific goals of the study are:

1. To develop a core set of questions that will address dimensions of HRQL that are universal to patients with chronic neurological disease
   
2. To develop supplemental questions or modules that address additional HRQL concerns that are specific to particular groups of patients defined by disease, age or other factors.