Huntingtons Disease, Current Research continued
Imaging technologies allow investigators to view changes in the volume and structures
of the brain and to pinpoint when these changes occur in HD.
Animal Models for HD
As more is learned about cellular degeneration in HD, investigators hope to reproduce
these changes in animal models and to find a way to correct or halt the process of nerve cell death. Such models also provide
a means to test the safety of new classes of drugs in nonhuman animals, including primates.
For example, the altered human HD gene is transferred into mouse embryos so that
the animals will develop the anatomical and biological characteristics of HD.
Fetal Tissue Research
Scientists are exploring the possibility of replacing tissue that has degenerated
with implants of fresh, fetal tissue, taken at the very early stages of development. Extensive animal studies will be required
to learn if this technique could be of value in humans with HD.
Clinical Studies of Patients
Clinical studies of patients are in progress to develop new drugs or other treatments
to halt the disease's progression. Examples of investigations, using both asymptomatic and symptomatic individuals, include:
Genetic studies on the age of disease onset, inheritance patterns, and
markers found within families.
Further genetic studies may shed additional light on how HD is passed from generation
Studies of thinking, intelligence, and movement.
Studies of abnormal eye movements, and tests of patients' skills in a number of learning,
memory, neuro-psychological, and motor tasks may serve to identify when the various symptoms of HD appear and to characterize
their range and severity.
Clinical trials of drugs.
Classes of drugs being tested for the treatment of HD in patients include those that
control symptoms, slow the rate of disease progression, and those that might correct or replace chemical imbalances in the
brain that contribute to the develop-ment and progression of HD.
A specialized imaging technique, positron emission tomography (PET), is being used
to learn how the gene affects the chemical systems of the body. PET visualizes metabolic or chemical abnormalities of tissue
in the body. Investigators conducting HD research are also using PET to charac-terize nerve cells that have died and chemicals
that are depleted in parts of the brain that are affected by HD.
Like PET, a form of magnetic resonance imaging (MRI) called functional MRI can measure
increases or decreases in certain brain chemicals thought to play a key role in HD. Functional MRI studies are also helping
investigators understand how HD kills nerve cells in different regions of the brain.
This report is based on information from the National Institutes of Health (NIH).