Friedreich's ataxia

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Central nervous system

Friedreich's ataxia

Alternative Names:

Spinocerebellar degeneration
Symptoms:

Unsteady gait and uncoordinated movements (ataxia) that gets progressively worse
Absent reflexes in the legs
Onset before age 25
Abnormal speech (dysarthria)
Loss of coordination and balance; frequent falls or falling more than usual
Decrease in vibration sense in lower limbs
Muscle weakness (decreased muscle strength, independent of exercise)
Autosomal recessive inheritance

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Note: The intellect is normal.

Symptoms are caused by degeneration of structures in the cerebellum and spinal cord responsible for coordination, muscle movement, and some sensory functions. Vision, particularly color vision, is often mildly affected. Hearing loss occurs in about 10% of patients.

Symptoms generally begin in childhood before puberty. Early symptoms include an unsteady gait, changes in speech, loss of reflexes, and jerky eye movements.

Abnormal muscle control and tone lead to spinal changes and scoliosis, or kyphoscoliosis may develop. Individuals with Friedreich's ataxia may also have hammer toe and high arches.

Heart disease usually develops and may progress into heart failure. Death may result from heart failure or dysrhythmias that will not respond to treatment. Diabetes may develop in later stages of the disease in up to one-third of patients.

Signs and tests:

The following tests may be performed:

ECG
Genetic testing for the frataxin gene
X-ray of the chest
X-ray of the spine
Electrophysiological studies
EMG (electromyography)
Nerve conduction tests
Muscle biopsy
X-ray, CT scan, or MRI of the head
Motor nerve conduction velocity of greater than 40 m/s with reduced or absent sensory nerve action potential
Hypertrophic cardiomyopathy (detectable in two-thirds of individuals with FRDA)
Diabetes occurs in 10% of individuals with FRDA, and an additional 20% may have glucose intolerance
Optic nerve atrophy, often without symptoms, occurs in approximately 25% of individuals with FRDA
Sensorineural hearing loss occurs in 10% of cases