Late-onset childhood neuronal ceroid lipofuscinosis: Early clinical and electroencephalographic markers.

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.