Overuse of EEG in the evaluation of common neurologic conditions

The objective of the present study was to analyze the diagnostic indications that most often prompt the referral of children and adolescents in the outpatient clinical pediatric practice for electroencephalographic evaluation and to check its utility in these clinical conditions. The electroencephalographic records of 547 consecutive children and adolescents (5-16 years of age) referred to a single community laboratory for the evaluation of various neurologic disorders were prospectively read by a single blinded investigator. Common diagnostic indications included the following: clinical seizures (42%), attention-deficit-hyperactivity disorder (23%), headaches (10.4%), syncope (9.9%), and tic disorder (4.9%). Overall, 76% of records were normal. Slowing of electroencephalographic activity was noted in 1% (attention-deficit-hyperactivity disorder) to 26% (probable epilepsy), and epileptiform activity in 53% of the probable and 29% of the clinically possible epileptics. Epileptiform activity was rarely found in the nonepileptic patients. The results of the present study demonstrate that standard interictal electroencephalogram is being overused during evaluation of various neurologic disorders in children and adolescents, suggesting that its use should be reserved for supporting the diagnosis in those cases in which epilepsy is a reasonable clinical possibility.