Annals of Clinical and Experimental NeurologyAnnals of Clinical and Experimental Neurology2075-54732409-2533Research Center of Neurology70810.54101/ACEN.2021.4.3Research ArticleEEG features in patients with Parkinson's disease during directional perception of olfactory stimuliKozhevnikovSergey P.<p>Cand. Sci. (Biol.), Associate Professor, Department of physiology, cell biology and biotechnology, Institute of Natural Sciences</p>ksp55@yandex.ruhttps://orcid.org/0000-0003-4753-0474IvanovaIrina L.<p>Cand. Sci. (Med.), Associate Professor, Department of neurology, neurosurgery and medical genetics</p>ksp55@yandex.ruhttps://orcid.org/0000-0002-6530-3497KomissarovaNatalia V.<p>Cand. Sci. (Med.), Head, Department of neurology, neurosurgery and medical genetics</p>ksp55@yandex.ruhttps://orcid.org/0000-0002-1319-9616ShubinaAnastasia V.<p>clinical resident, Department of neurology, neurosurgery and medical genetics</p>ksp55@yandex.ruhttps://orcid.org/0000-0002-7750-7235VlasovMatvey A.<p>student, Institute of Natural Sciences</p>ksp55@yandex.ruhttps://orcid.org/0000-0002-9623-6805Udmurt State UniversityIzhevsk State Medical Academy23122021154273523012021Copyright © 2021, Kozhevnikov S.P., Ivanova I.L., Komissarova N.V., Shubina A.V., Vlasov M.A.2021<p><strong>Introduction.</strong> Olfactory dysfunction is considered to be an early and relatively important marker of Parkinson's disease (PD). Olfactory studies using objective neurophysiological methods may become one of the diagnostic tests to identify individuals with a high risk of developing PD.</p>
<p>The <strong>aim</strong> of the study was to assess the spectral and topographic characteristics of bioelectrical brain activity in patients with PD during directional perception of olfactory stimuli.</p>
<p><strong>Materials and methods.</strong> This study included 30 patients with PD (mean age was 66.5 6.5 years). The control group consisted of 20 people without PD (mean age was 65.3 8.5 years). Lavender oil, clove oil, camphor oil and -mercaptoethanol solution (an aversive stimulus) were used for olfactory stimulation, while distilled water was used as a control test. The test subject sat with their eyes closed and inhaled the presented smell for 30 seconds, while an EEG recording was made during this time.</p>
<p><strong>Study results.</strong> Olfactory stimulation in patients with PD showed increased synchronicity of the <sub>3</sub> rhythm in the right hemisphere, as well as the rhythm in the parieto-occipital regions of both hemispheres. These changes indicate significant activation of internal (endogenous) attention, increased overall, non-specific readiness potential, as well as the involvement of the limbic-reticular complex in olfactory perception. Olfactory perception in the control group was accompanied by reduction in the <sub>1</sub> rhythm amplitude in the parieto-occipital regions bilaterally, which may indicate moderate activation of external (exogenous) attention and the posterior attention system responsible for simple perception processes.</p>
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