Ataxia is defined as the failure of muscle coordination that generally results in an unsteady gait and balance, limb or eye movements, and/or speech.
Friedreich's Ataxia is named after a German neurologist, Nikolaus Friedreich, who, in 1863, described this rare, inherited disease to the medical community.
Friedreich's Ataxia is also known as familial ataxia, Friedreich's disease, Friedreich's tabes, hereditary ataxia - Friedreich's type, spinal ataxia - hereditofamilial or spinocerebellar ataxia.
Friedreich's Ataxia is caused by an abnormality in one of the genes, called X25, located in the ninth chromosome pair. Genes are sets of instructions that tell the cells, containing chromosomes, how to build the proteins that enable these cells to carry out their various functions. These functions determine a person's physical characteristics, from the color of the hair and eyes to the organization of the nervous system.
Friedreich's Ataxia occurs when there is a lack of the protein frataxin (for which X25 provides the code) in the tissues. This lack of protein causes the nerve cells within the tissues of the spinal cord and its brain connections, the heart and pancreas to degenerate, thereby reducing nerve signals to the muscles.
The disorder develops only when a person inherits the defective gene from both parents. This is called a recessive inheritance pattern. If only one parent contributes a defective gene, the child becomes a "carrier" of Friedreich's Ataxia but never develops the disorder.
Carriers appear neurologically normal, and sometimes may not know they are carriers until an afflicted child is born to them. In the United States, it is estimated that 1 out of every 100 people is a carrier of the Friedreich's gene defect, and 1 of every 40,000 is affected with Friedreich's Ataxia. Each child of parents who are both carriers has a 25 percent chance of inheriting the disease.
Symptoms usually begin in childhood or youth (age 5 through 25) as a result of deterioration in areas of the brain controlling muscle coordination, the spinal cord and nerves. The symptoms may include:
- progressive weakness of the legs which may appear as a staggering, lurching way of walking (gait)
- reduced muscle coordination
- trembling when standing still
- partial loss of the sense of touch or sensitivity to pain and temperature
- arms and legs may become weak or numb
- paralysis of the lower limb
- impaired speech
- impaired swallowing
- spine may begin to curve to one side (scoliosis)
- feet may become rigid and deformed
- vision problems
- hearing problems
- diabetes develops
- heart muscles may be impaired (cardiomyopathy)
Diagnosis is based on a person's medical history, family history and a complete neurological evaluation which includes a electromyography (EMG). An EMG is a test in which the electrical activity in muscle is analyzed after being amplified, displayed and recorded. To supplement the evaluation, various tests may be performed which assist in the diagnosis and rule out other possible disorders that may present similar symptoms.
As with many degenerative diseases of the nervous system, there is no specific treatment. However, many of the following symptoms associated with Friedreich's Ataxia can be treated or controlled.
Symptom: Possible Treatment Method(s)
Diabetes: use of insulin
Tremors: use of propranolol
Muscle spasms: use of dantrolene sodium
Curvature of the spine: orthopedic surgery or braces
Foot deformities: orthopedic surgery or braces
Vision problems: corrective devices such as glasses and contact lens, surgery or medication
Hearing problems: hearing aids, surgery or medication
Muscle function: the use of physical therapy. Physical therapy is the treatment of disorders or injuries with physical methods or agents such as exercise, massage, heat treatment, ice packs, hydrotherapy (water-based) and light therapy.
Cardiomyopathy: diuretic and antiarrhythmic drugs or heart transplant
A wheelchair may be required for mobility.
What tests are performed to diagnose Friedreich's Ataxia?
What medications will be prescribed to treat some of the symptoms?
What are the side effects of the medication?
Is this condition curable?
What is the correlation between Friedreich's Ataxia and diabetes?
Can regular exercise be resumed?
What kind of diet is recommended for this condition?
With the discovery of the X25 gene (March 1996) that causes Friedreich's Ataxia, researchers are developing a DNA blood test to allow physicians to diagnose this disease with certainty. It will also enable individuals to learn, if they wish, whether they are carriers of the gene defect.