Doctors 'can turn off Parkinson's side-effect'

Dyskinesia causes involuntary movements -- including jerking and swaying -- and is a side-effect of the drug levodopa, used by more than half of Parkinson's patients.

It differs to the Parkinson's "tremor", which is a symptom of the disease itself. Levodopa is a chemical building-block that the body converts into dopamine -- the message transmitter that is missing in the brains of people with Parkinson's.

Now experts led by a team at Cardiff University have identified how an overactive system within nerve cells can lead the development of dyskinesia.

Silencing or "turning down" this system could possibly halt dyskinesia or slow its action.

Researcher Dr Riccardo Brambilla said: "Our work will pave the way for effective new treatments that can reduce or prevent dyskinesia. The challenge will be to target and block the right nerve cells in the brain which cause dyskinesia, without interfering with the positive benefits of levodopa."

The animal study, published in the journal Proceedings of the National Academy of Sciences, was funded by a range of organisations including the Michael J Fox Foundation.

Actor and writer Fox was diagnosed with young-onset Parkinson's in 1991 and set up the foundation to pursue research into the disease.

Dr Kieran Breen, director of research and development at Parkinson's UK, said: "We know just how distressing and widespread dyskinesia can be.

"This research is an important step forward in the search for better treatments that will make a real difference to the quality of life and confidence of thousands of people with Parkinson's."

hnews@herald.ie