CORTICAL POTENTIALS AND PARKINSONIAN TREMOR

Attempts to discover cortical potentials at the tremor frequency in Parkinson patients have in the past failed to disclose such potentials1-4. As the power to detect such potentials increased through the use of computerized time series analysis techniques, so did the power to detect artefactual correlations produced by electrode motion and lead sway4. By using recording electrodes on the surface of the cortex, restricting the bandwidth of the input data and using run lengths of 1 min or longer, we sought to maximize the possibility of detecting such potentials if they existed. The use of multiple cortical electrodes (only some of which might be expected to be recording from sources of tremor-related potentials) served as a control against the artefacts mentioned. © 1969 Nature Publishing Group.