ANN ARBOR, MI (MICHIGAN RADIO) - A Michigan State University researcher is working on new treatments for Parkinson's disease. 

Dr. John Goudreau says a protein known as "parkin" can save certain neurons in the brain from injury caused by Parkinson's disease.

The associate professor of neurology, pharmacology and toxicology is using a $1.5 million grant from the National Institutes of Health to explore his theory.

Goudreau uses a boxing analogy.

"So you have a couple of prizefighters," Goudreau says. "One gets hit and goes down to the mat and can't get up. These other cells that seem to be resistant to the disease take the same kind of hit, they go down to the mat, but they can bounce back up again and again. So we wanted to figure out why they were able to do that."

About four million people worldwide have Parkinson's disease. Goudreau says that's expected to increase to more than 8 million by the year 2030.

Of the three main types of oral drugs commonly added to levodopa therapy for patients with advanced Parkinson's disease, one might be the most effective, according to a new review.

People with Parkinson's disease often initially experience tremors, stiffness, slowed movement or difficulty with balance and coordination. These symptoms result from the destruction of brain cells that produce dopamine an important chemical that transmits nerve impulses.

Many people with Parkinson's start treatment by taking levodopa, which the body converts to dopamine. After a time, however, levodopa alone is not always enough.

The three classes of drugs for add-on treatment are dopamine agonists, which stimulate dopamine receptors in the brain, drugs known as COMT inhibitors and MAOB inhibitors, which slow the breakdown of dopamine in the body.

Of these, dopamine agonists might be most effective, according to a new review.

The irony for patients and doctors alike is that while all of the add-on drugs help improve functional motor skills, they simultaneously might increase numerous other side effects such as dyskinesia, dizziness, sleep disturbances, nausea, constipationand even hallucinations.

Although the risk of side effects increased with all three types of add-on drugs, patients were most likely to continue treatment when they were taking dopamine agonists. This class includes medications such as pramipexole (Mirapex), ropinirole (Requip), cabergoline (Dostinex) and bromocriptine (Parlodel).

"There's a tendency to think that stronger drugs give more adverse effects, but we didn't find that with dopamine agonists," says review co-author Carl E. Clarke, M.D., a neurologist at the University of Birmingham in England. "They seem to be as well tolerated as the other classes, so the results are quite positive in terms of using the agonists ahead of the other two."

Parkinson's disease is a chronic, progressive disorder affecting more than 6 million people worldwide, making it the most common degenerative condition of the brain after Alzheimer's disease. Both illnesses are most common in the elderly, so with an aging U.S. population, their prevalence is likely to increase.

"No treatments have been proven to slow progression of the disease," said William J. Weiner, M.D., director of the Maryland Parkinson's Disease and Movement Disorders Center at the University of Maryland Medical Center. "Yet with treatment to alleviate motor symptoms, most patients can function extremely well for six to 10 years."

Levodopa typically controls symptoms very well for up to five years, but eventually a patient's symptoms start to reappear each day before the next dose is due or symptoms might reappear and disappear unpredictably. Patients might also develop dyskinesia, which results in uncontrollable jerking and writhing movements.

Doctors can then add another medication to the levodopa therapy.

"The greater efficacy and reduced likelihood of patient withdrawal with dopamine agonist therapy possibly outweighs the disadvantage of increased side effects," concludes the review.

This finding matches Weiner's clinical experience gained from decades of treating people with the disease.

"Most [Parkinson's] patients prefer to have these dyskinesias and other moderate side effects than to have more disabling motor complications like being unable to walk," he says. "Hallucinations may be troublesome and frightening initially, but they are typically benign a patient might think he sees a dog and people can get used to them."

The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates research in all aspects of health care. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.

This review assessed data from 44 randomized trials involving 8,436 participants. The authors caution, however, that the studies compared each class of drugs against placebo, rather than conducting "head-to-head" comparisons of each class against the others.

This leaves open the possibility that the findings arose not from actual differences in the treatments, but rather from other factors such as differences in the types of people included in the various trials. A large trial featuring direct comparisons of the three drug classes currently is underway in the United Kingdom, Clarke said.

Of the drugs in the COMT inhibitor class, the review suggests that tolcapone (Tasmar) is as effective as the dopamine agonists. However, tolcapone has been linked to a few cases of fatal liver toxicity and can now only be prescribed in the United States with intense monitoring.

"Tolcapone is worth using in patients where [the alternative] is not working well, and we mustn't discount it," Clarke said. "This evidence clearly states that."

The review disclosed that Clarke has received payments for consulting, lectures and travel from Boehringer-Ingelheim, GlaxoSmithKline, Lundbeck, Orion, Teva, UCB, and Valeant.

The Cochrane Library contains high quality health care information, including Systematic Reviews from The Cochrane Collaboration. These reviews bring together research on the effects of health care and are considered the gold standard for determining the relative effectiveness of different interventions. The Cochrane Collaboration is an international nonprofit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions.

Stowe R, et al. Evaluation of the efficacy and safety of adjuvant treatment to levodopa therapy in Parkinson s disease patients with motor complications (Review). Cochrane Database of Systematic Reviews 2010, Issue 7.

(Health Day News) -- A combination of genetic mutations and exposure to insecticides may increase a man's risk of Parkinson's disease, new research shows.

The study included 207 Parkinson's disease patients and a control group of 482 healthy people. The French team of researchers analyzed the participants for mutations in a gene called ABCB1 and assessed their lifetime exposure to pesticides.

Overall, mutations in the ABCB1 gene weren't associated with Parkinson's disease risk. However, the researchers found that the association between organo chlorine insecticide exposure and Parkinson's disease was 3.5 times stronger in men with two mutated copies of the ABCB1 gene than among those with no ABCB1 mutations.

"Based on a biological hypothesis, we show that organo chlorine insecticides may interact with ABCB1 in determining the risk of Parkinson's disease,"Fabien Dutheil, of Universite Paris Descartes, Assistance-Publique Hopitaux de Paris, and colleagues concluded. "These findings support the hypothesis of gene x pesticide interactions in Parkinson's disease."

The study is published in the June issue of the Archives of Neurology.

AP State Wire

The state has awarded nearly $10 million in grants to fund stem cell research at Yale and the University of Connecticut.

The grants, which are the fourth round of state stem cell funding, will fund 22 projects that span areas such as the role of stem cells in understanding or treating Huntington's disease, leukemia, Parkinson's disease and osteoarthritis.

The grants come from a $100 million state fund for stem cell research established in 2005 when federal funding for research using human embryonic stem cells was restricted.

Federal policy has since changed, but scientists and policymakers say state funding has helped Connecticut in stem cell research, allowing universities to develop labs and recruit scientists.

Health Day

A new voice analysis technique can identify changes in speech associated with the early stages of Parkinson's disease, a new study has found.

"This is a noninvasive, reliable and accurate technique that only requires the patient to read out a few simple sentences," Shimon Sapir, of the department of communication sciences and disorders at the University of Haifa in Israel, who developed the new test, said in a university news release.

In many cases,Parkinson's disease is diagnosed based on muscle rigidity, tremors, slow movement and loss of balance. But by the time these symptoms are present, the disease is already well-advanced.

Since the muscles controlling voice and speech are affected in most people with Parkinson's disease, Sapir decided to develop an acoustic analysis method that identified differences between the speech of people with Parkinson's disease and healthy people. The method also tracks voice changes that occur in response to treatment or disease progression.

A series of tests showed that the new acoustic analysis technique is effective. The findings were published in a recent issue of the Journal of Speech, Language and Hearing Research.

"Doctors and scientists agree that early diagnosis of Parkinson's disease is important in order to slow down or even prevent the degenerative progress of this disease,"Sapir said. "Today no treatment is available to this effect, but when treatment becomes feasible, early diagnosis is going to be crucial.There are various methods of brain imaging for detecting early signs of Parkinson's disease, but these methods are expensive -- particularly when attempting to screen a large population at risk. Hence the importance of developing techniques for early diagnosis that are valid,reliable, non-invasive, simple, readily available and inexpensive."

But Sapir added that "while our initial results are very encouraging,additional studies must be carried out in order to examine the new method. Also, given that the disease and its progression have different effects on individuals, speech analysis must be incorporated into a battery of tests that examine other signs and symptoms of the disease,such as changes in handwriting, cognitive functions, sense of smell, and more."