Improvement in word-fluency performance in Parkinson's disease by administration of electromagnetic fields

The association between degeneration of the nigrostriatal dopamine (DA) system and the motor manifestations of Parkinson's disease (PD) provided the impetus for the development of DA replacement therapy. However, clinical experience has demonstrated that DA-ergic drugs, while attenuating the motor symptoms of PD, have little or no consistent effect on the mental and cognitive symptoms of the disease which are thought to be related partly to degeneration of the meso-cortico-limbic DA system. Thus, failure of DA-ergic drugs to improve the mental and cognitive deficits of PD indicates that these agents cannot fully restore DA functions in the meso-cortico-limbic circuits. The present communication concerns five fully medicated Parkinsonian patients in whom application of a series of treatments with electromagnetic fields (EMF) of extremely low intensity (in the picotesla range) and frequency (5-8Hz) produced a dramatic improvement in performance on Thurstone's World-Fluency Test, a sensitive marker of frontal lobe functions. These findings suggest that in contrast to DA replacement therapy application of low intensity EMF may improve frontal lobe functions in patients with PD presumably by augmenting DA activity in the mesocortical system. As deficiency of the frontal DA system has been implicated also in the development of akinesia and freezing in PD these observations may explain the beneficial effects of EMF on the motor manifestations of the disease.