Causes

• Friedreich's ataxia is an autosomal recessive congenital ataxia and is caused by a mutation in gene FXN (formerly known as X25, which codes for frataxin, located on chromosome 9.
• The mutant gene contains expanded GAA triplet repeats in the first intron.

• The primary site of pathology is spinal cord and peripheral nerves.

• Sclerosis and degeneration of dorsal root ganglion, spinocerebellar tracts, lateral corticospinal tracts, and posterior columns

• In peripheral nerves there is a loss of large myelinated fibres.

Clinical symptoms

Symptoms typically begin sometime between the ages of 5 to 15 years, but in Late Onset ataxia may occur in the 20s or 30s.

• Muscle weakness in the arms and legs
• Loss of coordination
• Vision impairment
• Hearing loss
• Slurred speech
• Curvature of the spine (scoliosis)
• High plantar arches (pes cavus deformity of the foot)
• Diabetes
• Heart disorders (e.g., atrial fibrillation, and resultant tachycardia (fast heart rate) and hypertrophy cardiomyopathy)

Clinical signs

• Cerebellar: Nystagmus, fast saccadic eye movements, truncal titubation, dysarthria, dysmetria.
• Pyramidal: absent deep tendon reflexes, extensor plantar responses, and distal weakness are commonly found.
• Dorsal column: Loss of vibratory and proprioceptive sensation occurs.
• Cardiac involvement occurs in 91% of patients, including cardiomegaly (up to dilated cardiomyopathy), symmetrical hypertrophy, murmurs, and conduction defects.
• Median age of death is 35 years, while females have better prognosis with a 20-year survival of 100% as compared to 63% in men.
• 20% of cases are found in association with diabetes mellitus type 1 or 2 or pancreatic β cell dysfunction.

Treatment

Currently, there is a treatment approved is drug idebenone (co-enzyme Q 1o derivative).

As the disease may be associated with free radical damage to cells antioxidants such as Vitamin E and coenzyme Q10 are frequently prescribed.

• 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 person suffering from Friedrich's Ataxia may require some surgical interventions (mainly for the spine and heart).

Often a metal rod is inserted in the spine to help prevent or slow the progression of scoliosis.

As progression of ataxia occurs, assistive devices such as a cane, walker, or wheelchair are required for mobility and independence.

Other assistive technology, such as a standing frame, can help reduce the secondary complications of prolonged use of a wheelchair.