The neuronal ceroid lipofuscinoses (NCL) are a group of genetic lysosomal storage diseases characterized by dementia, epilepsy, motor deterioration and mostly also visual loss through retinal degeneration. As a group, they represent one of the most frequent etiologies of dementia in young persons. The present classification of the NCL disorders is based on the different genes involved and on the age at clinical onset, which can be anytime between the infantile and young adult age. We describe typical clinical pictures that may be caused by NCL types in the different age groups and an economic strategy for their diagnosis. While experimental therapies aiming to stop disease progression are being developed, palliative therapies may be disease-specific and can bring significant relief. This applies particularly to the therapy of the frequently drug-resistant epilepsy in NCL.