# Use of Covariance Analysis in Electroencephalogram Reveals Abnormalities in Parkinson's Disease
## 4 Results  
### General Wavelet Profiles of Control and Parkinson's Disease Patients under 60 Years Old (<60)  
Figure 5 shows the general wavelet profiles of CL and PD patient groups <60. Figure 5A shows the global wavelet curves profile for CL <60 (\(n\) = 3 crossings per channel). In this group, a main \(\alpha\) brainwave was observed with a frequency value of 9.52 \(\pm\) 1.81 Hz and a power of 0.89 microV\({}^{2}\). A secondary \(\delta\) brainwave also was identified with a frequency value of 2.67 \(\pm\) 0.55 Hz and a power of 0.39 microV\({}^{2}\). Figure 5B shows the main frequencies profile for CL <60, where the main brainwave was \(\alpha\) with frequency values of 8.99, 9.52 and 10.09 Hz. The 8.99 Hz frequency was mainly observed in the Fp channels, the 9.52 Hz frequency was localized in the T channels and the 10.09 Hz frequency was found in the O channels. Figure 5C shows the power anomalies profile for CL <60; Fp, F and T channels had positive anomalies with mean power values of 0.9, 0.7 and 1.1, respectively. P and O channels had negative anomalies with mean power values of \(-\)1.0 and \(-\)1.2, respectively. The C channels remained with power mean values near to zero. The anteroposterior gradient was observed from high to low power with a slope of \(-\)0.14. The Fp, F and T channels had power 2.5 times higher than the P and O channels. Figure 5D shows the brainwave power for CL <60; the highest power was in \(\alpha\) brainwave. For this group, \(\delta\) power was the half of the \(\alpha\) power and \(\delta\) power corresponded to one-third of the \(\alpha\) power; the power values were 0.57 and 0.32, respectively.  
Figure 5E shows the global wavelet curves profile for PD patients <60 (\(n\) = 1 crossing per channel). A main \(\alpha\) brainwave was observed with a frequency of 9.52 \(\pm\) 1.96 Hz and power of 0.95 microV\({}^{2}\). A secondary \(\delta\) brainwave was also identified with a frequency of 2.67 \(\pm\) 0.49 Hz and power of 0.35 microV\({}^{2}\). Figure 5F shows the main frequencies profile for PD patients <60; the \(\alpha\) brainwave was the representative with values of 8.99, 9.52 and 10.09 Hz. The 8.99 Hz frequency was observed in the Fp and C channels. The 9.52 Hz frequency was mainly identified in the O-right channels, while the 10.09 H frequency was found in the O-left channels. Figure 5G shows the power anomalies profile for PD patients <60; Fp, F and C channels had negative anomalies with mean power values of \(-\)0.9, \(-\)0.8 and \(-\)0.5, respectively. T, P and O channels had positive anomalies with mean power values of 1.3 for the T and O channels and 0.3 for P channels. The anteroposterior gradient was observed from low to high power with slope of 0.12. The O channels had a power 1.7 times higher than the Fp and F channels and P channels had one 1.4 times higher. The C channels in this group showed negative values that were larger than in control group. Figure 5H shows the brainwave power for PD patients <60; the highest power was in \(\alpha\) brainwave. For this group, \(\delta\) and \(\theta\) brainwaves had one-third of the \(\alpha\) power; the power values were 0.37 and 0.32, respectively.