• Ataxia is a common finding in these patients. Other symptoms of brain stem and cerebellar dysfunction that allow the localization of the lesion to be determined are impaired eye movements, hearing loss, facial paralysis, and difficulty swallowing.
Friedreich's Ataxia
• Involves the cerebellum, dorsal spinal cord, spinocerebellar tracts, pyramidal tracts and medulla.
• The number of homozygous GAA repeats increased in the gene encoding the mitochondrial protein frataxin.
The mutation causes oxidative damage associated with excessive iron accumulation in mitochondria.
• There are two inherited types. The most common OR form is seen between 5-10 years of age. The OD form occurs a little later.
• Progressive ataxia is seen in all patients, usually beginning before the age of 10. Ataxia progresses slowly and is more pronounced in the lower extremity than in the upper extremity. It is accompanied by weakness and destruction of the distal muscles, and sometimes spasticity.
• Vibration and position sense are absent (Romberg is positive) and there is little loss of sensation to sharp pain. DTR not available, Babinski positive.
• Patients speak explosively and dysarthric, often accompanied by nystagmus.
• Skeletal deformities such as pes-cavus, kyphoscoliosis and deafness are seen.
• Hypertrophic cardiomyopathy causing congestive heart failure is the most common cause of death.
