Childhood dementia is a collective term for 250 rare, neurodegenerative diseases in children and adolescents. 1 in 2,000 to 1 in 500,000 children in Germany are affected, depending on the form of the disease.

The most common forms of dementia in children are:Neuronal ceroid lipofuscinosis (NCL), known as "Batten's disease" in English-speaking countries. Approximately 40 percent are affected by various forms of leukodystrophy, hereditary metabolic diseases of the white brain substance substantia alba.