Autosomal recessive spastic ataxia of Charlevoix

Autosomal recessive spastic ataxia of Charlevoix (ARSACS) is a rare autosomal recessive spastic ataxia unique to the region of Charlevoix-Saguenay in the province of Quebec, Canada. It is due to a mutation on the SACS gene locus q12 of chromosome 13. It has been reported in other regions of the world since it was discovered, including Netherlands ⁹, Brazil ⁷, Italy ⁴ & France ¹⁰.

Clinical presentation

Patients usually present with lower limb spasticity at gait initiation around 1 year-old. Gradually, patients usually develop a slurred speech with distal amyotrophy and are wheelchair bound by 40 years-old.

Radiographic features

Patients with autosomal recessive spastic ataxia of Charlevoix are frequently investigated with head CT and MRI.

Superior vermis atrophy is caracteristically always present in patient with ARSACS ⁵. A tigroid pattern of the pons has been described (linear hypointensity on T2-WI), and is mainly seen in ARSCACS ¹¹.

Other common, however not specific findings include ^1-2-3-4 :

• inferior vermis atrophy
• superior spinal cord atrophy
• cerebellar hemisphere atrophy
• bulky pons with hypointense T2 stripe
• thalamic T2 hyperintensities
• corpus callosum thinning