Effect of weak electromagnetic fields on the amplitude of the pattern reversal VEP response in Parkinson's disease.
Visual evoked potential (VEP) studies are widely used for the diagnosis of multiple sclerosis (MS) and are also useful in monitoring the effects of various therapeutic modalities in the disease. Prolongation of the VEP latencies has been demonstrated in patients with MS and in other neurodegenerative disorders including Parkinson's disease (PD), a disorder characterized by deficient cerebral dopamine (DA) functions. Pharmacological and biochemical studies have demonstrated a positive correlation between the amplitude of the VEP response and cerebral DA levels. Since brief, extracerebral applications of picotesla (pT) range flux intensity electromagnetic fields (EMFs) of low frequency have been shown to produce rapid improvement in motor and cognitive symptoms in PD, it is expected that application these EMFs would lead also to an increase in the amplitude of VEP response. This report documents three randomly selected PD patients who, following two successive brief extracerebral applications of pT range EMFs, showed an almost 3-fold increase of the mean pretreatment amplitude of the pattern reversal VEP in response to monocular stimulation. One patient underwent also a placebo EMF treatment which did not result in a significant change in the posttreatment amplitude. The study demonstrates that in Parkinsonian patients extracerebral application of these EMFs rapidly increases in amplitude of the VEP response and, by inference, cerebral DA levels presumably by increasing DA release.
Sandyk
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NeuroCommunication Research Laboratories, Danbury, CT 06811, USA.
D000368:Aged; D004574:Electromagnetic Fields; D005074:Evoked Potentials, Visual / Q000502:physiology / Q000528:radiation effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology*; D010775:Photic Stimulation