Fall, 2013
Treatments for movement disorders such as Parkinson’s disease and dystonias are often classified into two groups based on their actions in the body: symptomatic and disease modifying. Symptomatic therapies treat the symptoms of the disease but do not address the underlying cause. Disease-modifying therapies target the underlying cause of the disease.
For all of major neurological diseases, including movement disorders, we would ideally have disease-modifying therapies that would fix the alterations in the brain or in a person’s genes that cause the symptoms. However, true disease-modifying therapies are not yet available for Parkinson’s disease or dystonias.
Disease-modifying therapies depend on understanding the basic biology of movement disorders, as well as the development of safe and effective treatments that can get into the brain. The brain has a special system of protection known as the blood-brain barrier that is designed to keep out unwanted chemicals. This system is so effective that it keeps out many potential treatments. As a result, researchers face the challenge not only of finding a treatment that targets the disease process, but also of getting it into the brain.
Symptomatic therapies get around the problem of the blood-brain barrier in several ways. Some treatments are small drugs that can cross easily into the brain because of their size. Other medications are injected directly into overactive muscles and therefore avoid the brain altogether. In deep brain stimulation, tiny electrodes are surgically implanted directly into the brain where they produce signals that help modulate movement.
Researchers are busy developing both new symptomatic treatments for movement disorders and treatments they hope will modify the disease processes. Below is a brief list of some of the types of disease-modifying therapies under study.
- Dystonias
- Search for genes underlying the disease, potential development of protein therapies or gene therapies that help fix the underlying genetic problem(s), search for ways to get the gene and/or protein therapies into the brain
- Parkinson’s disease
- Search for genes underlying the disease, potential development of protein therapies or gene therapies that may help fix any underlying genetic problem(s), search for medications that can help break up aberrant protein clusters, development of growth factor therapies (proteins that may help neurons grow back), stem cells that would replace the lost nerve cells.
This article originally appeared on page 3 of the Fall, 2013 PMDF newsletter.