On the synchronizing effect of amantadine-1-hydrochlorid (Symmetrel) on pathological EEG-activity.

The pathological EEG of a 60 years old lady who suffered from an organic mental syndrome with parkinsonian features, showed diffuse, slow asynchroneous activity. Administration of Symmetrel repeatedly and consistently caused a normalization of the EEG, while its discontinuation immediately led to the reappearance of the original desynchronized pattern. These EEG changes were not accompanied by any modifications in the patients' clinical condition. This discrepancy between the antiparkinsonian and the synchronizing effect of Symmetrel upon the EEG can be explained by a specific activity on the reticulo-thalamo-cortical pathways in addition to that upon the nigro-striatal tracts.