Seizures are a major manifestation of several lysosomal storage diseases. This chapter discusses neurons of lipids or glycoconjugates, which include the neuronal ceroid lipofuscinoses, the gangliosidoses, the sialidoses, and two of the mucopolysaccharidoses, Hunter syndrome and Sanfilippo disease. The galactolipidoses, Krabbe disease, and metachromatic leukodystrophy (MLD), are also discussed, because they secondarily affect neurons and clinically present with seizures. Finally, two transport disorders, one lysosomal, Niemann-Pick disease type C, and the other, Menkes disease, a non-lysosomal X-linked disorder, join these other seizure-provoking hereditary metabolic syndromes because of identifiable metabolic abnormalities within neurons. Progressive neuropsychiatric deterioration appears from the late infantile period manifesting as ataxia, dystonia, dysphagia, dysarthria, seizures, cataplexy, and cognitive deterioration. Seizures are almost constant and include asymmetric myoclonic jerks that can be stiumulus-provoked. Plasma dopamine and dihydroxyphenylacetic acid are elevated due to low dopamine beta-hydroxylase activity.