1 Historical Background -- 1.1. Chorea in the Middle Ages: The Dancing Mania -- 1.2. Thomas Sydenham and Chorea -- 1.3. From Sydenham to Huntingdon: The First Descriptions of Inherited Chorea -- 1.4. Huntington's Chorea -- 2 Genealogy and Geographic Distribution -- 2.1. Genealogical Methods -- 2.2. Genealogical Investigations in Various Parts of the World -- 2.3. The Importance of Genealogical Investigations -- 2.4. The Original Source of the Gene for Huntington's Chorea -- 3 Epidemiology -- 3.1. Diagnostic Critera -- 3.2. Prevalence -- 3.3. The Epidemiology of Juvenile Huntington's Chorea -- 3.4. Incidence -- 3.5. Mortality Data -- 4 Natural History -- 4.1. Age at Onset -- 4.2. Age at Death -- 4.3. Duration -- 5 Clinical Features -- 5.1. The Presenting Symptoms and Signs -- 5.2. General Manifestations -- 5.3. Neurological Features -- 5.4. Mental Disturbance -- 5.5. Staging -- 5.6. Variants -- 5.7. The Clinical Features of Juvenile Huntington's Chorea -- 5.8. Diagnostic Techniques -- 5.9. Problems of Diagnosis -- 6 Neuropathology -- 6.1. Gross Pathology -- 6.2. Findings on Light Microscopy -- 6.3. Ultrastructural Features -- 6.4. The Importance of Post-mortem Examination -- 6.5. The Brain and Tissue Bank -- 7 Genetics -- 7.1. Mutations -- 7.2. Heterozygote Frequency -- 7.3. The Homozygous Form -- 7.4. Heterogeneity -- 7.5. Unusual Aspects of the Genetics of Juvenile Huntington's Chorea Ill -- 7.6. Genetic Registers -- 7.7. Genetic Counselling -- 7.8. Reproductive Fitness -- 8 Living with Huntington's Chorea: The Social Perspective -- 8.1. Psychosocial Consequences for the Affected Person -- 8.2. The Experience of Being At Risk -- 8.3. The Burden on the Unaffected Spouse -- 8.4. Huntington's Chorea: A Family Disease -- 8.5. Antisocial Behaviour: Huntington's Chorea and the Law -- 8.6. The Economic Burden -- 9 Management -- 9.1. A Rational Approach to Pharmacotherapy -- 9.2. Surgery -- 9.3. Other Therapeutic Modalities -- 9.4. Future Prospects -- 10 Current Trends in Research -- 10.1. A Unifying Conceptual Approach -- 10.2. Investigations of the Abnormal Gene -- 10.3. The Search for the Altered Gene Product -- 10.4. The Investigation of Disturbed Cell Function/Structure -- 10.5. Viruses -- 10.6. Neurochemistry -- 10.7. Neuroendocrine Disturbances -- 10.8. Predictive Tests -- 10.9. Conclusion -- Appendixes -- 1. The Use of Conditional Probabilities in Genetic Counselling for Huntington's Chorea -- 2. Method for Determination of the Mutation Rate in Huntington's Chorea.. -- 3. Method for Determination of the Heterozygote Frequency in Huntington's Chorea -- 4. Name of Addresses of Lay Organisations and Other Centres for Information on Huntington's Chorea -- 5. Brain Donation Programme