en Internal Medicine Specialist پژوهشي orginal article <span style="line-height:1;"><span style="font-family:Times New Roman;"><span style="font-size:16px;"><strong>Background</strong> Orthostatic syncope is a significant public health concern. The study investigated the comparative effects<br> of prolonged orthostasis and single intermittent prolonged orthostasis on the electroencephalogram in adult males.<br> The objectives were to investigate the comparative impacts of prolonged orthostasis and single intermittent prolonged<br> orthostasis on the alpha wave frequency, beta wave frequency, and alpha/beta ratio.<br> <strong>Methods</strong> The study adopted a pre-experimental study design (pre-(baseline) and post-comparison). Forty adult male<br> individuals were selected through the respondent-driven sampling technique. Measurements were conducted at a<br> reclining sitting position (baseline). The participants then underwent 20 minutes of orthostasis, followed by a single<br> intermittent, prolonged orthostatic challenge. Orthostasis was defined as the assumption of upright standing from a<br> sitting position for 20 minutes, and single intermittent prolonged orthostasis consisted of a 1-minute break between<br> two consecutive 20-minute orthostasis periods. Electroencephalographic (EEG) recordings were obtained using a<br> PowerLab 26T, as previously reported. The machine has an in-built hardware filtering (low pass filter of 1-2000Hz)<br> and software-based filtering (Labtutor). Statistical significance was accepted at p < 0.05.<br> <strong>Results</strong> When compared to baseline and intermittent orthostatic sessions, respectively, orthostasis has no significant<br> decrease (p > 0.05) in alpha wave frequency. However, alpha/beta ratio and beta wave frequency were significantly<br> lower and higher (p < 0.05) during orthostasis when compared to baseline and intermittent orthostatic sessions,<br> respectively.<br> <strong>Conclusion</strong> The findings of the study suggest that prolonged orthostasis (20 minutes) relatively elicited greater<br> cortical activation when compared to single intermittent prolonged orthostasis in adult male individuals. Cautions are<br> advised while subjecting patients to orthostatic tolerance tests.</span></span></span> Electroencephalogram, Electroencephalography, Orthostasis, Orthostatic stress, Standing position 328 333 http://ijrabms.umsu.ac.ir/browse.php?a_code=A-10-439-3&slc_lang=en&sid=1 Mayowa Jeremiah Adeniyi 7jimade@gmail.com 10031947532846005558 10031947532846005558 Yes Department of Physiology, University of Rwanda, Rwanda Ayoola Awosika ayoolaawosika@yahoo.com 10031947532846005559 10031947532846005559 No Department of Family and Community Medicine, University of Illinois College of Medicine, Peoria, USA Phoebe Nwamaka Kanikwu nwakanikwu@gmail.com 10031947532846005560 10031947532846005560 No Department of Nursing, Edo State University, Uzairue, Nigeria