Retinal and pontine striations: neurodiagnostic signs of autosomal recessive spastic ataxia of Charlevoix-Saguenay.

A 39-year-old man with long-standing ataxia, spasticity, dysarthria, and peripheral neuropathy was found to have diffuse thickening of the retinal nerve fiber layer in both eyes, as manifested by prominent retinal striations and confirmed by optical coherence tomography. Magnetic resonance imaging showed severe atrophy of the superior cerebellar vermis with linear "footprint" hypointensities in the pons with irregular striations. Genetic testing confirmed the diagnosis of spastic ataxia of Charlevoix-Saguenay (ARSACS). The clinical evaluation of progressive cerebellar ataxia should include a dedicated search for retinal nerve fiber layer thickening, which establishes the diagnosis of ARSACS.