Degenerative brain diseases have an enormous impact on our aging society. Alzheimer's disease progressively robs its victims of their memory. Parkinson's disease leads to impairments in movement. Frontotemporal dementia causes bewildering changes in a person's thoughts and behaviour. Huntington's disease painstakingly deprives a person of their ability to walk, talk, think and reason, often as early as in their mid 30s and 40s.