![]() ![]() RESULTS Suppression of Tremor and LFP Activitiesįigure 1 shows a representative example of changes in tremor and STN LFP during stimulation at incrementally increased voltages. Correlation coefficients were normally distributed and their difference from zero tested using a one-sample t-test. To examine the relationship between tremor amplitude and LFP band power within hemispheres, correlation analyses were performed using Spearman’s correlation. Where Greenhouse–Geisser corrections were applied, corrected degrees of freedom are cited. Accordingly, in this subject, values for 1.5–2V were conservatively repeated for 2.5–3V. In one subject, tremor was totally suppressed at 2.0 V and stimulation therefore not performed at higher intensities. Where more than one value was available for each hemisphere in a given stimulation range (e.g., 0.5 and 1 V), these were averaged. ![]() The unstimulated baseline was not used as, with normalization, this had a value of 1. Spectral decomposition with a continuous wavelet transform was performed because of its efficient time frequency resolution and lack of assumptions regarding stationarity (Ĭhanges in tremor amplitude and LFP band power were assessed in separate repeated measures ANOVAs during the 0.5–1 V, 1.5–2 V, and 2.5–3 V ranges of stimulation and Bonferroni correction applied. These data were then taken forward for further analysis. The amplitudes for all points were then averaged over each stimulation block to give a single value of amplitude for the tremor and LFP in each frequency band for each level of DBS stimulation. For the tremor signal, this was centered on the peak frequency ☑ Hz, and for the LFP this was calculated for all frequencies between 1 and 45 Hz before being averaged across the bands of interest. The amplitudes of both the tremor signal and the LFP were calculated using a Morlet wavelet transformation. Both the LFP and selected accelerometer data were divided into epochs of 100 sec in which each epoch represented stimulation with a certain fixed voltage (0–max 4.5 V). The accelerometer axis that recorded the greatest tremor amplitude was selected for further analysis. Levodopa, Ropinirole, Rasagiline, AmantadineĪfter visual inspection, LFPs and tri-axial accelerometer signals were analyzed offline using custom-written scripts in MATLAB (version 7.10 MathWorks, Natick, MA, USA). Levodopa, Entacapone, Pramipexole, Selegeline Table 1 Clinical and Stimulation Details of Patients
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |