Neurological Disorders: Friedreich ataxia

Friedreich ataxia (FA) is the commonest genetically determined ataxia and its mode of inheritance is AR (autosomal recessive).

It results from a mutation in chromosome 9 which causes deficiency of an important protein by name frataxin that is normally present in tissues and organs like nervous system, heart etc.

It occurs in all races & ethnicities. Both boys & girls are affected. It is AR, means both parents must be possessing the genetic mutation for their kids to get this disease; also if both parents have this mutation then each of their child has 25% chance of developing the disease.

The disease usually starts manifesting during childhood or early adolescence but cases do occur outside this age range too.

Spino-cerebellar tracts, dorsal root ganglia, peripheral nerves, cranial nerves, heart etc are the organs & tissues that are commonly involved.

• Gait ataxia
• In coordination of the limbs & body
• High arching of the foot (pes cavus) clawing of the toes (hammer toe)
• Decreased deep tendon reflexes
• Up going big toe (babinski sign)
• Peripheral neuropathy findings in the extremities especially the feet (e.g. stocking distribution loss of sensation)
• Cardio myopathy
• Cardiac arrhythmias
• Cataracts
• Hearing deficits
• Scoliosis
• DM (Diabetes mellitus)

Patients will have progressively worsening course and eventually become wheel chair dependent.

The below investigations are generally required for establishing the diagnosis as well as managing the cases;

• Genetic tests
• EMG/NCS (electromyography & nerve conduction studies)
• Blood tests like blood sugar, vitamin E etc
• Echocadiogram, EKG/ECG etc for heart
• Eye examination
• Audiometric tests for hearing etc

FA is a degenerative neurological disorder without any cure so far. The treatment is supportive & symptomatic. Patient’s various symptoms like numbness, tingling etc are treated with medications. Physical & occupation therapy are given. DM & heart conditions are treated aggressively. Assistive devices and orthopaedic devices are necessary as disease advances.

A neurologist (pediatric and/or adult) is frequently involved in the care of patients with friedreich ataxia.