Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Drug aimed at Huntington’s eases chorea, the disease’s hallmark feature

14.02.2006


A drug widely available in Europe and Canada – but not the United States – dramatically eases one of the most disabling symptoms of Huntington’s disease, involuntary writhing movements known as chorea, according to a study in the Feb. 14 issue of the journal Neurology.



The medication, tetrabenazine, is currently being reviewed by the U.S. Food and Drug Administration. If approved, the medication would be the first authorized by the agency expressly for the treatment of Huntington’s disease, which affects about 30,000 people in the United States.

In a randomized, controlled study conducted in 84 patients at 16 sites around the nation, doctors found that the medication cut down involuntary movement on average by about 25 percent, with many patients experiencing a greater improvement. Overall, patients who received the medication were six times as likely to be considered by their doctors to have improved considerably, compared to participants who received a placebo.


“Neuroleptic drugs like haloperidol (Haldol) are currently in widespread use in the United States to suppress chorea, but the effect of these drugs on chorea has never been studied in a systematic way, and they have a number of troublesome side effects, such as blunting of personality, loss of voluntary movement, and hindering balance. Our study showed that tetrabenazine, when appropriately dosed, can decrease chorea without causing those side effects,” said Frederick J. Marshall, M.D., a neurologist at the University of Rochester Medical Center who led the study conducted by the Huntington Study Group. The study was funded by Prestwick Pharmaceuticals of Washington, D.C., the company that owns the rights to develop and sell the medication in the United States.

Tetrabenazine was originally developed in the 1950s to treat psychosis, but was quickly pushed aside by more effective medications. But doctors in the United Kingdom found it to be effective to treat the excessive involuntary movements of Huntington’s, and it is approved for use in several nations. In the United States, tetrabenazine is designated as an “orphan drug” by the FDA since it’s targeted to a disease directly affecting fewer than 200,000 people in the nation.

The symptom that tetrabenazine treats – involuntary, writhing movements of the limbs, face, and sometimes the entire body – is the hallmark symptom of Huntington’s disease, an inherited neurodegenerative disorder that worsens as brain cells known as medium spiny neurons are killed off by a mutant protein. The disease brings with it an array of other difficulties as well, including cognitive problems, changes in personality, and psychiatric problems like depression. As many as one-quarter of patients with the disease attempt suicide, and many suffer from progressive cognitive decline. Unlike Alzheimer’s disease, where patients usually lose their memory and insight into their disease at some point, most Huntington’s patients understand exactly what is happening to them throughout most of their illness.

The disease usually strikes people in their 30s and 40s, though some patients are affected as early as childhood, while others aren’t affected until their older years. Virtually everyone with the disease had a parent with the disease, and children of a person with Huntington’s have a 50-percent chance of inheriting the disease. Thirteen years ago the gene that causes the disease was identified by scientists, and now a simple blood test can tell people whether they will develop the disease or not. But since there is no way known to prevent the disease or slow its progression, and for other reasons as well, many patients decline the test, instead waiting to see if they develop symptoms like the ones they witnessed in a parent. Patients usually live for 15 to 20 years after the onset of symptoms.

Viewed simply, in some ways Huntington’s disease is the opposite of Parkinson’s disease, where damage to the neurons that produce dopamine hinders a person’s ability to move and cause other symptoms. In Huntington’s, too many dopamine signals result in random, uncontrollable movements. Tetrabenazine inhibits a molecule known as vesicular monoamine transporter 2 (VMAT2), an action that ultimately blocks the release of dopamine.

“This is not a wonder drug for Huntington’s. It doesn’t address the psychiatric or cognitive problems, for instance. But there are some patients for whom chorea is clearly a devastating feature of the illness.” said Marshall, an associate professor of Neurology who is chief of the University’s Geriatric Neurology Unit. “Easing chorea could help patients with tasks they normally struggle with, such as eating, driving, grooming, and walking.

“As a physician, I have no doubt that this medication can be very helpful to some patients. If the drug is approved, physicians will need to work closely with patients and their caregivers to adjust the dosage safely. About a quarter of patients reported sedation, fewer than 10 percent of patients had motor restlessness, and fewer than 5 percent had motor slowing or depressed mood. Side effects generally resolved with downward adjustment of the dosage. Of concern, one patient committed suicide during the study. Because of the high rate of suicide attempts in patients with Huntington’s disease, all patients deserve close follow-up.”

The study was carried out by the Huntington Study Group, a non-profit, cooperative group of Huntington’s disease experts from medical centers throughout North America, Europe and Australia who are dedicated to improving treatment for persons affected by the disease. HSG is supported by the Huntington’s Disease Society of America, the Hereditary Disease Foundation, the Huntington Society of Canada, and the High Q Foundation. More information is available at www.Huntington-Study-Group.org.

HSG is based at the University of Rochester Medical Center, which is home to one of the world’s top groups of doctors specializing in Huntington’s disease. The study was run through the Department of Neurology’s Clinical Trials Coordination Center, where physicians design and conduct large multi-site studies of potential new treatments for diseases like Parkinson’s disease, Huntington’s disease, and neurological disorders related to HIV.

Marshall is part of a team of doctors, scientists and nurses that treats people from more than 200 families from throughout the Northeast with the disease. He also specializes in the treatment of patients with Parkinson’s and Alzheimer’s diseases.

“There’s something compelling about this disease,” said Marshall. “I feel very close to my patients with Huntington’s disease. I’m inspired by them. To a person, they are courageous and compassionate. Even in the face of something as difficult as Huntington’s disease, my patients preserve a sense of dignity and grace.

“These are people who live every day with the burden of knowing that there is not yet a cure, and that their closest loved ones are themselves at 50/50 risk of getting the disease. Many of them grew up caring for a parent or a sibling with the illness, so they are fully aware of the symptoms and signs of the disease as it progresses. Yet, even in the face of this, they maintain optimism and a sense of humor. It is an honor to be part of the extended community of patients, families, and researchers trying to find a better way forward.”

Tom Rickey | EurekAlert!
Further information:
http://www.urmc.rochester.edu
http://www.Huntington-Study-Group.org

More articles from Studies and Analyses:

nachricht Real-time feedback helps save energy and water
08.02.2017 | Otto-Friedrich-Universität Bamberg

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Positrons as a new tool for lithium ion battery research: Holes in the electrode

22.02.2017 | Power and Electrical Engineering

New insights into the information processing of motor neurons

22.02.2017 | Life Sciences

Healthy Hiking in Smart Socks

22.02.2017 | Innovative Products

VideoLinks
B2B-VideoLinks
More VideoLinks >>>