Auditory event related potentials as tools to reveal cognitive late effects in childhood cancer patients

ObjectiveThe purpose of this study was to analyze event related potentials mismatch negativity (MMN) and P3a in childhood cancer patients at the time of diagnosis (Study 1) and after treatment (Study 2) to evaluate their clinical usefulness in screening potential treatment-related neurotoxicity.MethodsThe MMN and P3a to phonetic stimuli were examined in 27 childhood cancer patients with age- and sex-matched controls. Neuropsychological tests were also studied.ResultsThe MMN peak amplitude was attenuated in the patient group at Study 1. Between the studies, poorer enhancement of the MMN peak amplitude correlated with deterioration in the Verbal intelligence quotient (IQ) in leukaemia patients. In addition, prolongation of the MMN peak latency correlated significantly with deterioration in the Full Scale and Performance IQ in the patient group. Deterioration in the Arithmetic subtest and Performance IQ correlated negatively with the age at diagnosis.ConclusionsThe MMN changes between the studies associated with deterioration in the neuropsychological tests indicating that the method could be clinically useful. The performance of the younger patients was more likely to deteriorate during the treatment.SignificanceChanges in the MMN response during cancer treatment seem to be of clinical importance as indicates of the cognitive outcome of childhood cancer patients.