Huntington's Disease (HD) and Multiple Sclerosis (MS) are both severe chronic diseases. In addition to the neurological problems, psychic symptoms are common and together with the steadily progressing course leading to increasing problems in activities of daily life and physical disability. Partnership problems and sexual dysfunction is often reported in chronic diseases but many physicians feel uncomfortable or inadequately trained to discuss these issues with their patients. Although not life-threatening, these conditions are associated with a considerable amount of unhappiness and decreased quality of life. When receiving diagnosis most of the patients are just in progress of having a family on their own or making career. The increased dependence, especially on the partner can be a big strain on relationships. This book deals with the topic of sexuality and partnership in HD and MS and contains a detailed description of the existing literature as well as the investigations and findings of a study with HD and MS patients interrogated by a personal interview and standardised questionnaires.