Nejm 1996;335:1169

Cause:Genetic, autosomal dominant or recessive on chromosome 9, causing multiple GAA after 1st intron

Pathophys: Basic process is a neuronal decay. Symmetric degeneration of posterior columns, spinocerebellar tracts, posterior roots, and corticospinal tracts

Prevalence = 1/50 000

Sx: Onset before puberty in most, all by age 25 yr. Weakness

Si: Ataxia w dysarthria, chronic peripheral neuropathy, pes cavus (high-arched feet)

Die by age 30-40 yr of infections and cardiac causes

Optic atrophy and myocarditis with heart block and fibrosis late in course; diabetes

r/o other causes of ataxia (Movement Disorders)

Lab:

Noninv: EKG shows arrhythmias

Path:Absence of neurons in posterior root ganglia, anterior horns, posterior horns, motor and cerebellar cortices

Rx: None available