New treatment improves symptoms of Parkinson's disease

Patients with advanced Parkinson's disease have shown dramatic improvements in the preliminary results of a small pilot study of a technique whereby a growth factor is pumped directly into dopamine deficient areas of the brain.

Neurologists working at the Frenchay Hospital in Bristol implanted catheters in the brains of five patients with Parkinson's disease (unilaterally affected, Hoehn and Yahr stage III; age range 46-62 years). The catheters were situated in the dorsal putamen—the region of the brain controlling movement that becomes deficient in the neurotransmitter dopamine in Parkinson's disease.

Two pumps in the anterior abdominal wall then continuously pumped glial derived neurotrophic factor, which is needed for the development of dopaminergic neurons, into the brain at a dosage of approximately 14μg/day. One of the researchers, Dr Steven Gill, consultant neurosurgeon at the Frenchay Hospital, explained: “We can deliver a drug very precisely to areas in the brain in the concentrations that we need to cause recovery, and we can control that very precisely.”

The preliminary results showed marked improvement in the symptoms of Parkinson's disease in all five of the patients taking part in the pilot. The patients all improved in their ability to walk, and one patient regained his sense of smell. Patients improved across a wide range of measures—including the united Parkinson's disease rating scale (UPDRS), SF-36 (a quality of life scale), and timed motor tasks.

Dr Gill reported: “All patients were as good in their off state [when symptoms are at their most severe] as their preoperative on state. In their on state patients improved on the UPDRS by 44% In their off state they improved by 54% This level of improvement has not been seen with any other treatment—it is even better than the best results achieved with cell transplantation.”

He was surprised at the speed of the effect. “We thought that this drug would take some months or years to be effective, but we found that really within a month or two patients were noticing significant changes.”

The results were presented last week at the 54th annual meeting of the American Neurological Association, in Denver, Colorado, and will be published in the next few weeks. However, Dr Gill stressed that the results were preliminary and that it remains to be seen how long the improvements last and whether the treatment would suit all patients with Parkinson's disease.

Patients in the Bristol study are being scanned with positron emission tomography to assess whether the treatment achieves changes in the areas of the brain that have been damaged by the disease.

Roger Nelson, one of the patients who has benefited

(Credit: BARRY BATCHELOR/PA)