Neurophysiological follow-up in two children with Creutzfeldt-Jakob disease after human growth hormone treatment

A serial neurophysiological study has been performed of 2 children during the clinical course of Creutzfeldt-Jakob disease after human growth hormone (hGH) treatent. Evolution of the EEG pattern was typical: slow waves, periodic sharp wave complexes, then extinction. VEP components were moderately altered. BAERs performed in only 1 child were normal. The blink reflex (BR) showed an early alteration of the R1 component. The ERG exhibited early and profound anomalies. Pathological changes were obvious at the first recording, at the beginning of the second month after clinical onset: increase in peak latencies, morphological changes and important reduction of b wave amplitude (a/b amplitude ratio ⩾ 0.70; normal range 0.27–0.41). The ERG was completely absent a few months later. These results are compared with the similar retinopathy described in CJD- or scrapie-infected rodents. In the 2 children, pathological changes in ERG and in BR were obvious several months before the development of the typical EEG pattern. Therefore, early ERG and BR recording can be helpful in the diagnosis of CJD, especially in this ataxic form following hGH treatment.