ELECTROENCEPHALOGRAPHIC FINDINGS IN PATIENTS WITH MUCOLIPIDOSIS TYPE-IV

Objective: To describe the electroencephalographic findings in mucolip idosis type IV (ML IV), a lysosomal storage disease of unknown etiolog y characterized clinically by corneal clouding, retinal degeneration a nd severe psychomotor retardation. Most patients are of Ashkenazi-Jewi sh ancestry. The EEG findings in this syndrome have not been character ized. Methods: We analyzed the EEGs of 10 patients with the diagnosis of ML IV, aged between of 2.5 and 21 years. All patients had 21 channe l recordings in the international 10/20 system without sedation. Resul ts: Six of the 10 patients had slowing of the background in the theta frequency range, and 4 had excessive beta frequency activity without t he administration of medications. Two patients were able to reach stag e 2 sleep, and were noted to have both synchronous and asynchronous sp indles and vertex waves. Of the 10 patients, 6 had epileptiform spikes , all of which were noted frequently. The location of the spikes varie d, from the frontal and temporal regions to the central regions, altho ugh location was consistent in each patient. Only one patient with epi leptiform spikes had a history of clinical seizures. None of the other patients had a history of seizures. Conclusions: These findings imply that epileptiform discharges are common in patients with ML IV, but a re infrequently associated with clinical seizures. (C) 1998 Elsevier S cience Ireland Ltd.