###### Abstract  
Parkinson's disease (PD) is the fastest growing neurological disease associated with ageing; its symptomatology varies between sexes. Several quantitative electroencephalography analyses have been used to study the early stages and progression of PD. In this study, we aim to characterize the brain activity by considering the five brainwaves in an eyes-closed resting state, using covariance wavelet analysis (CWA) of electroencephalographic records (EEGs) to analyze the influence of sex and age. To effectively eliminate artifacts from the EEG dataset and extract pertinent brain activity, we employ the inverse wavelet analysis. EEGs from men with PD were divided into two age groups (PD \(<\) 60 and PD \(>\) 60 years old) with their respective age-matched controls (CL). Brain activity patterns in frequency and power domains were analyzed with the CWA. Main frequency profiles, global wavelet curves, power anomalies, and power per brainwave were used to illustrate the CWA patterns. Power anomalies were used to generate anteroposterior power gradients. In PD \(<\) 60 men, frequency and power for the \(\alpha\) brainwave decreased, while the \(\delta\) brainwave increased. The \(\theta\) brainwave increased and was dominant over the \(\alpha\) brainwave in PD \(>\) 60 men. The anteroposterior power gradient in PD \(<\) 60 men had a positive slope, but it was negative in CL. In both PD and CL \(>\) 60 men, the anteroposterior gradient was negative. In PD \(>\) 60 men, the \(\theta\) brainwave increased and became dominant. Men with PD had twice the \(\theta\) brainwave increase. An inverse relationship between \(\alpha\) and \(\delta\) brainwaves was detected in a PD \(<\) 60 sex comparison. A conventional EEG spectral analysis using CWA indicated significant differences in brain activity patterns in the PD/CL groups affected by sex and age, yielding previously unknown information. c 2023 13 9618 2023 2  
also have worse general cognitive impairment shown through verbal fluency assessments, specifically, in tests of category fluency and category switch [8]. Furthermore, men take longer to complete inhibition tests (a section of the color word interference test) and have a significant deficit in cognitive flexibility in processing speed tests. It has also been observed that men with PD present greater deficits in frontal executive abilities such as attention [8]. The diagnosis of the early stages of PD has been challenging to neurologists, and it is a current main aim to uncover its origin through animal and human models that replicate some aspects of the symptomatology of the disease. Evidence has shown that PD initially affects the brain in multiple nuclei, such as the _motor nucleus of the vagus, raphe nuclei, locus coeruleus, pedunculopontine nucleus, parabrachial nucleus_, and the _ventral tegmental area_. These brain nuclei are associated with the non-motor symptomatology of PD. In the later stages of the disease, the progressive degeneration of the dopaminergic neurons in the nigrostriatal pathway of the _substantia nigra pars compacta_ impairs movement regulation, being the standard observation for clinical diagnosis [9]. The etiology of 90% of PD cases is unknown, while the remaining 10% is related to genetic mutations of specific proteins, mainly \(\alpha\)-Synuclein, a ubiquitous protein synthetized by several tissues such as brain (neurons and glia) [10], skeletal muscle [11; 12] and blood cells [13]. Although a specific mutation of \(\alpha\)-Synuclein (A53T) accounts for most cases of PD arising at \(<\)40 years of age [14; 15], aggregated \(\alpha\)-Synuclein is found in most PD post-mortem brains studied, regardless of its genetic or sporadic origin [7]. How non-mutated \(\alpha\)-Synuclein is present in sporadic PD and how it alters brain proteostasis is yet to be uncovered. In any case, genetic or sporadic, PD involves non-motor and motor symptoms. Major motor symptoms include tremors, rigidity, and bradykinesia [9].