Electroencephalographic features in a series of patients with neuronal ceroid lipofuscinoses

We report the electroencephalographic (EEG) features of 22 patients with ne uronal ceroid lipofuscinoses (NCL) who were referred to the Neurological In stitute of Milan between 1984 and 1998. The EEG data were reviewed, taking into account the different forms of NCL on the basis of age at onset, clini cal features and morphological appearance. The study group included patient s with infantile NCL (one case), late-infantile NCL (ten cases), juvenile N CL (seven cases) and adult NCL (four cases). We looked for the presence of homogeneous EEG features associated with these different forms, particularl y in the early phases of the disease. Our data indicate that the EEG charac teristics of late-infantile NCL and of the myoclonic form of adult NCL are quite distinctive, and that their particular spontaneous epileptiform anoma lies and response to intermittent light stimulation can be considered relev ant diagnostic clues at an early disease stage.