RESUMO
PURPOSE: The objective of the study was to describe the initial clinical and electroencephalographic findings in children with late-infantile neuronal ceroid lipofuscinosis (LINCL). METHOD: The clinical charts of 35 patients seen between 1990 and 2016 were reviewed. The patients were divided into two groups: Group 1 (G1) consisting of 12 patients with NCL type 2 (CLN2) disease confirmed by enzymatic activity in dried blood spots on filter paper and/or genetic studies, and Group 2 (G2) consisting of 23 patients with a diagnosis of LINCL based on pathology studies by muscle biopsy. RESULTS: Mean age at symptom onset was 3 years in G1 and 3.4 years in G2. Symptoms at onset were epilepsy in 58%, language delay in 34%, and gait disturbances in 8% of patients in G1 and epilepsy in 52.1%, language delay in 26%, gait disturbances in 17.4%, and loss of visual acuity in 4.5% in G2. The most common seizure types in G1 patients were myoclonic in 3/7, generalized tonic-clonic in 2/7, focal motor in 1/7, and febrile seizures in 1/7; in G2 patients they were myoclonic in 5/12, generalized tonic-clonic in 3/12, myoclonic-atonic in 2/12, and febrile seizures in 2/12. A photoparoxysmal response to intermittent photic stimulation (IPS) was found in the initial EEG in 9/12 patients in G1 (mean age 3.8 years) and in 10/13 patients in G2 (mean age 3.9 years). CONCLUSIONS: There were no significant differences between both groups. Seizures, especially myoclonic, are the most common symptom at onset followed by language delay and gait disturbances. Low-frequency IPS is a useful study that may help facilitate the diagnosis of the disease.