Long-term Neuropsychologic Outcome in Children Diagnosed with a Lysosomal Storage Disease

In this thesis we focus on the brain and the neuropsychological sequelae in patients with lysosomal storage disorders (LSDs). Up till now studies on the consequences of brain involvement for neuropsychological development in patients with LSDs is limited. Although most LSDs have in common that they are caused by a single lysosomal enzyme deficiency, the storage products differ and as a consequence the effect on the brain and cognitive development varies between the different types of LSDs. Studies on the neuropsychological profile of patients with the different LSDs help to reveal the commonalities and differences and the new insights may be instrumental for a better understanding of the pathophysiological mechanisms leading to the differential effects on cognition. A better understanding on the neuropsychological profile is also needed to support patients, their parents and families, physicians, other caretakers and teachers. Finally, knowledge on neuropsychological involvement in patients with LSDs is a prerequisite to appreciate the effect of potentially new treatment modalities targeting the brain.

All of these considerations led us to study the neuropsychological consequences of lysosomal storage diseases in four very different LSDs; Pompe disease, Alpha-mannosidosis, Hunter Syndrome (MPS II), and Maroteaux-Lamy Syndrome (MPS VI).