Visual and verbal learning and memory in cystinosis

Cystinosis is a rare genetic lysosomal storage disorder characterized by the accumulation of cystine in lysosomes. Many organ systems are vulnerable to this cystine accumulation including the CNS. A past study demonstrated that children with cystinosis have deficits in visual learning and memory while their verbal learning and memory and global intellectual function are spared (Spilkin, Ballantyne, & Trauner, 2009). However, no related study has been performed to assess the dissociation between visual and verbal learning and memory in adults with cystinosis who have had the benefit of longterm treatment with the cystine-depleting agent, cysteamine. In this study we assessed visual and verbal learning and memory in 15 adults with cystinosis, with a mean age of 30.2 years. The results indicate that adults with cystinosis have no significant deficits in either verbal or visual learning and memory. However, the individuals did perform better on the verbal assessment. The results suggest that if early and continued treatment is given to individuals with cystinosis there is a relative sparing of visual learning and memory that might have otherwise declined. This emphasizes the essential nature of the proper clinical management of cystinosis.