Devices
Well-fitted orthoses can promote correct posture, support normal joint alignment, stabilize joints during walking, improve range of motion and gait, reduce spasticity, and prevent foot deformities and scoliosis.Functional electrical stimulation or transcutaneous nerve stimulation devices may alleviate symptoms.As progression of ataxia continues, assistive devices such as a cane, walker, or wheelchair may be required for mobility and independence. A standing frame can help reduce the secondary complications of prolonged use of a wheelchair. Medication and surgery
Cardiac abnormalities can be controlled with ACE inhibitors such as enalapril, ramipril, lisinopril, or trandolapril, sometimes used in conjunction with beta blockers. Affected people who also have symptomatic congestive heart failure may be prescribed eplerenone or digoxin to keep cardiac abnormalities under control.Surgery may correct deformities caused by abnormal muscle tone. Titanium screws and rods inserted in the spine help prevent or slow the progression of scoliosis. Surgery to lengthen the Achilles tendon can improve independence and mobility to alleviate equinus deformity. An automated implantable cardioverter-defibrillator can be implanted after a severe heart failure. Prognosis
The disease evolves differently in different people. In general, those diagnosed at a younger age or with longer GAA triplet expansions tend to have more severe symptoms.Congestive heart failure and abnormal heart rhythms are the leading causes of death, but people with fewer symptoms can live into their 60s or older. Epidemiology
FRDA affects Indo-European populations. It is rare in East Asians, sub-Saharan Africans, and Native Americans. FRDA is the most prevalent inherited ataxia, affecting approximately 1 in 40,000 with European descent. Males and females are affected equally.
The sensory neurons essential for directing muscle movement of the arms and legs through connections with the cerebellum are particularly affected. The disease primarily affects the spinal cord and peripheral nerves. The spinal cord becomes thinner and nerve cells lose some myelin sheath. The diameter of the spinal cord is smaller than that of unaffected individuals mainly due to smaller dorsal root ganglia. The motor neurons of the spinal cord are affected to a lesser extent than sensory neurons. In peripheral nerves, a loss of large myelinated sensory fibers occurs.Structures in the brain are also affected by FRDA, notably the dentate nucleus of the cerebellum. The heart often develops some fibrosis, and over time, develops left-ventricle hypertrophy and dilatation of the left ventricle. Frataxin
The exact role of frataxin remains unclear. Frataxin assists iron-sulfur protein synthesis in the electron transport chain to generate adenosine triphosphate, the energy molecule necessary to carry out metabolic functions in cells. It also regulates iron transfer in the mitochondria by providing a proper amount of reactive oxygen species (ROS) to maintain normal processes. One result of frataxin deficiency is mitochondrial iron overload, which damages many proteins due to effects on cellular metabolism.Without frataxin, the energy in the mitochondria falls, and excess iron creates extra ROS, leading to further cell damage. Low frataxin levels lead to insufficient biosynthesis of iron–sulfur clusters that are required for mitochondrial electron transport and assembly of functional aconitase and iron dysmetabolism of the entire cell.