Huntington's Disease

Huntington's disease (HD) is a hereditary and degenerative brain disorder affecting about 30,000 Americans. One hundred and fifty thousand more run the risk of inheriting Huntington's from one of their parents (Read about "Genetics"), according to the National Center for Biotechnology Information (NCBI). The symptoms, according to the Huntington's Disease Society of America (HDSA), are caused by a degeneration of cells in part of the brain. (Read about "The Brain") The damaged cells, HDSA says, can affect thinking, judgment, memory, movement and emotional control. Dr. George Huntington of Long Island, NY first published a description of the disease back in 1872, but according to HDSA, little has been known about Huntington's until recently.

The gene

Huntington's disease affects men and women equally, as well as people of all races, according to HDSA. The common link among sufferers is the HD gene, whose mutation results in the disease. It is a gene that scientists finally positively identified in 1993. HDSA says this gene is passed from parent to child. Each child of an affected parent has a 50 percent chance of inheriting the HD gene. If they do carry the gene, HDSA says they will eventually develop Huntington's. HDSA says those who do not inherit the gene will not develop the disease, nor will their children. The National Institute of Neurological Disorders and Stroke (NINDS) says the HD gene is not inherited in 1 to 3 percent of people who have HD, but appears to be the result of a new mutation. While the discovery of the gene has helped scientists understand the disease, there is still no cure for HD.

What causes HD

Neurons are nerve cells in the brain. (Read about "Nervous System") HD occurs when there is a degeneration of the nerve cells, according to NINDS. This gradual degeneration results in physical, mental and emotional deterioration. Specifically affected, according to NINDS, are the cells of the basal ganglia. This region is located at the base of the brain and is made up of clusters of nerve cells. The area is responsible, according to NINDS, for functions like body movement and coordination. Also affected is the part of our brain along the outside edge called the cortex. It controls thoughts, perception and memories.

Symptoms

NINDS says early signs of HD vary from person to person but may include some of the following emotional symptoms:

• mood swings
• anger
• depression
• irritability

As the disease progresses some people may experience motor symptoms. HDSA says some of those signs include:

• uncontrolled movements in the feet, face, fingers, or trunk which is called chorea
• clumsiness
• problems with balance
• impaired speech and swallowing

HD sufferers may exhibit problems with judgment and memory. HDSA says patients may have some of the following cognitive symptoms: (Read about "Dementia")

• short-term memory loss
• difficulty organizing routine matters
• trouble dealing with new situations

While some patients can't recognize members of their own family, NINDS says many are aware of their environment and can express emotions. HD can last from 10 to 30 years according to NINDS. People don't usually die from HD itself, but rather from a complication like infection or injuries from a fall.

Age and HD

Symptoms of HD usually appear between the ages of 30 and 45 according to HDSA, but children may also develop symptoms of the disease. This occurs in about ten percent of all HD cases and is called juvenile HD, according to HDSA. The juvenile form is also called Westphal variant. Children most often inherit the disease from their fathers. Adult-onset is inherited evenly from mothers and fathers. HDSA says the symptoms of this form of HD are somewhat different from adult-onset Huntington's. Initial symptoms of juvenile HD may involve:

• stiff walking and talking
• choking
• clumsiness

Later a child may show problems in school. HDSA says the onset of juvenile HD is generally more rapid than adult-onset HD.

Diagnosis

According to NINDS, an experienced neurologist should have no trouble diagnosing HD, but that may not always be the case. In 1967 the great American folk singer and composer, Woody Guthrie died after suffering with HD for 13 years. Years prior to his diagnosis he had been misdiagnosed and shuttled in and out of mental institutions and treated for alcoholism. His case, according to NINDS, is not unusual.

Diagnosis, according to HDSA can be accomplished by a full examination, which may entail the following:

• neurological exam
• physical exam
• detailed family history (Read about "Family Health History")
• MRI (magnetic imaging response) or CT (computerized tomography) (Read about "MRI - Magnetic Resonance Imaging" "CT Scan - Computerized Tomography")
• genetic test (Read about "Laboratory Testing")

The genetic test cannot only help confirm the diagnosis of HD; it can also help rule out the disease. However, HDSA says a positive test result alone is not enough to confirm a diagnosis of HD. The disease, according to HDSA can mimic other disorders like alcoholism and Parkinson's disease. (Read about "Alcoholism" "Parkinson's Disease")

Treatment

While current treatments cannot reverse the effects of HD, they can ease some symptoms, according to HDSA. Medications can help with depression, anxiety and involuntary movements. (Read about "Depressive Illnesses" "Anxiety") HDSA warns however that many drugs have side effects. It's important to speak with a neurologist who has experience in treating HD. HDSA says a physician familiar with the disease can provide the best ongoing care and treatment. HDSA says an occupational therapist or speech therapist may also help in improving the quality of life. NINDS recommends a safe exercise regimen and a nutritious diet. People with HD tend to need more calories to maintain their body weight. They are also at risk for dehydration, according to NINDS, and need more fluids, especially during hot weather. (Read about "Dehydration")

Effects on the family

HD affects almost every member of the family, especially as the disease progresses. A spouse or partner may become the primary care giver, according to HDSA. They will have to take responsibility for many of the day-to-day duties, as well as making decisions, and taking care of the children. That's because HD sufferers may no longer be able to take on these tasks. Children living with a parent who has HD may even be asked to take part in caring for their parent. Every family is different and therefore every family situation will vary; however, HDSA recommends an open attitude when it comes to HD. The organization suggests that parents tell their children about HD slowly and honestly.

New research

There are several areas of research, which are slowly coming together and helping us to understand better how the HD gene affects the mind and body. Since 1977, Congress has provided support for federal research, mainly through NINDS, which is the government's lead agency for biomedical research on disorders of the brain and nervous system. (Read about "Nervous System") According to NINDS, the following methods are being used in hopes of learning more about HD:

• Animal Research: Scientists are breeding laboratory animals with hopes of duplicating the features of HD. This could enable them to learn more about the symptoms and progression of the disease.
• Neurobiology: With the location of the HD gene, experts in neurobiology can further study the gene and how it causes disease.
• Clinical Research: Scientists are pursuing studies that may lead to new drugs or other treatments to stop the disease's progression. (Read about "Clinical Studies")
• Imaging: Scientists are using positron emission tomography (PET) and other technologies with hopes of gaining information about how the gene affects the body's chemistry. (Read about "PET - Positron Emission Tomography")

Since the discovery of the HD gene, research has accelerated and according to NCBI is critical to the development of effective treatments for HD and similar diseases. HDSA believes that continued support of HD research could not only lead to breakthrough treatments, but a cure as well.