Researchers in Japan have started a trial of a treatment for Parkinson's disease by injecting genes into a patient. This is reportedly the first clinical trial of this treatment method in the country.

A team at the Jichi Medical University Hospital started the trial on Monday. A male patient in his 50s participated.

The team injected the genes directly into the man's brain, with the aim of stimulating the body to produce a chemical called dopamine, a brain chemical that sends mobility signals to other parts of the body.

Parkinson's is a progressive disease in which patients gradually lose the ability to move. Their limbs may tremble and the body becomes rigid. The disease is caused by abnormalities in the cells responsible for the production of dopamine.

Twelve patients will be monitored over the next year to check the safety and efficacy of the treatment. The scientists say they aim to gain approval to use it as a new treatment method.

Muramatsu Shinichi, a professor at the Jichi Medical University who led the group, said a long-term improvement in symptoms can be expected from one treatment session, if the dopamine is generated. He said he wants to help mitigate patients' stress and improve their quality of life.

The health ministry says there are more than 140,000 Parkinson's patients in Japan. There are medicines to relive symptoms or slow its progression, but a basic cure has yet to be found.
Researchers in and outside Japan are exploring methods to cure the disease, including a clinical trial by a Kyoto University team that involves iPS technology.