Parkinson's disease might be triggered by damage to the powerhouses of brain cells, according to genetic tests. Researchers at Newcastle University found that neurons in a region of the brain called the substantia nigra had high levels of damaged DNA in their mitochondria, the tiny structures that give cells their energy.

"Mitochondria in a cell are comparable to batteries. If the batteries are not charged up, the cell cannot function," said Professor Ian McKeith at the Institute of Ageing and Health at Newcastle University. The study appears in the journal Nature Genetics.