Examinando por Autor "Duschek, Stefan"
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Ítem Aberrant Cerebral Blood Flow Responses during Cognition: Implications for the Understanding of Cognitive Deficits in Fibromyalgia(American Psychological Association, 2015) Montoro, Casandra I.; Duschek, Stefan; Muñoz, Cristina; Fernández, María José; Reyes del Paso, Gustavo A.Objective: There is ample evidence for cognitive deficits in fibromyalgia syndrome (FMS). The present study investigated cerebral blood flow responses during arithmetic processing in FMS patients and its relationship with performance. The influence of clinical factors on performance and blood flow responses were also analyzed. Method: Forty-five FMS patients and 32 matched healthy controls completed a mental arithmetic task while cerebral blood flow velocities in the middle (MCA) and anterior (ACA) cerebral arteries were measured bilaterally using functional transcranial Doppler sonography (fTCD). Results: Patients′ cognitive processing speeds were slower versus healthy controls. In contrast to patients, healthy controls showed a pronounced early blood flow response (during seconds 4–6 after the warning signal) in all assessed arteries. MCA blood flow modulation during this period was correlated with task performance. This early blood flow response component was markedly less pronounced in FMS patients in both MCAs. Furthermore, patients displayed an aberrant pattern of lateralization, with right hemispheric dominance especially observed in the ACA. Severity of clinical pain in FMS patients was correlated with cognitive performance and cerebral blood flow responses. Conclusions: Cognitive impairment in FMS is associated with alterations in cerebral blood flow responses during cognitive processing. These results suggest a potential physiological pathway through which psychosocial and clinical factors may affect cognition. (PsycInfo Database Record (c) 2022 APA, all rights reserved)Ítem Cerebral blood flow modulations during cognitive control in major depressive disorder.(Elsevier, 2018) Hoffman, Alexandra; Montoro, Casandra I.; Reyes del Paso, Gustavo A.; Duschek, StefanBackground: This study investigated cerebral blood flow modulations during proactive and reactive cognitive control in major depressive disorder (MDD). Proactive control refers to preparatory processes during anticipation of a behaviorally relevant event; reactive control is activated after such an event to ensure goal attainment. Methods: Using functional transcranial Doppler sonography, blood flow velocities in the middle cerebral arteries of both hemispheres were recorded in 40 MDD patients and 40 healthy controls during a precued Stroop task. The font color of color words, which appeared 5 s after an acoustic warning signal, had to be indicated while ignoring word meaning. Results: Patients, as compared to controls, exhibited smaller bilateral blood flow increases during task preparation and larger increases after color word presentation. Response time was longer in patients irrespective of the match or mismatch between font color and word meaning. The blood flow increase after word presentation correlated positively with response time. Limitations: Potential effects of psychotropic medication on cognition and cerebral blood flow could not be controlled. Conclusions: The study revealed evidence of reduced cortical activity during proactive and elevated activity that occurs during reactive control in MDD. Deficient implementation of proactive control in MDD may lead to increased reliance on reactive control. The association between the blood flow increase after color word presentation and poorer performance indicates that deficient response preparation cannot be compensated for by reactive strategies. The findings are clinically relevant, as they may contribute to our understanding of the mechanisms relevant to cognitive impairments in MDD.Ítem Cerebral blood flow modulations during proactive control in chronic hypotension.(Elsevier, 2018) Duschek, Stefan; Hoffman, Alexandra; Bair, Angela; Reyes-del-Paso, Gustavo; Montoro-Aguilar, Casandra IsabelIn addition to complaints including fatigue, mood disturbance, dizziness or cold limbs, chronic low blood pressure (hypotension) is associated with reduced cognitive performance. Deficiencies in cerebral blood flow regulation may contribute to this impairment. This study investigated cerebral blood flow modulations during proactive control in hypotension. Proactive control refers to cognitive processes during anticipation of a behaviourally relevant event that allow optimization of readiness to react. Using functional transcranial Doppler sonography, bilateral blood flow velocities in the middle cerebral arteries were recorded in 40 hypotensive and 40 normotensive participants during a precued Stroop task. Hypotensive participants exhibited smaller bilateral blood flow increases during response preparation and longer response time. The group differences in blood flow and response time did not vary by executive function load, i.e. congruent vs. incongruent trials. Over the total sample, the flow increase correlated negatively with response time in trials with a higher executive function load. The findings indicate reduced cerebral blood flow adjustment during both the basic and more complex requirements of proactive control in hypotension. They also suggest a general deficit in attentional function and processing speed due to low blood pressure and cerebral hemodynamic dysregulations rather than particular impairments in executive functions.Ítem Cerebral blood flow variability in fibromyalgia syndrome: Relationships with emotional, clinical and functional variables(Plos, 2018) Montoro, Casandra I.; Duschek, Stefan; Schuepbach, Daniel; Gandarillas, Miguel A.; Reyes del Paso, Gustavo A.Objective: This study analyzed variability in cerebral blood flow velocity (CBFV) and its association with emotional, clinical and functional variables and medication use in fibromyalgia syndrome (FMS). Methods: Using transcranial Doppler sonography, CBFV were bilaterally recorded in the anterior (ACA) and middle (MCA) cerebral arteries of 44 FMS patients and 31 healthy individuals during a 5-min resting period. Participants also completed questionnaires assessing pain, fatigue, insomnia, anxiety, depression and health-related quality of life (HRQoL). Results: Fast Fourier transformation revealed a spectral profile with four components: (1) a first very low frequency (VLF) component with the highest amplitude at 0.0024 Hz; (2) a second VLF component around 0.01-to-0.025 Hz; (3) a low frequency (LF) component from 0.075-to-0.11 Hz; and (4) a high frequency (HF) component with the lowest amplitude from 0.25-to-0.35 Hz. Compared to controls, FMS patients exhibited lower LF and HF CBFV variability in the MCAs (p < .005) and right ACA (p = .03), but higher variability at the first right MCA (p = .04) and left ACA (p = .005) VLF components. Emotional, clinical and functional variables were inversely related to LF and HF CBFV variability (r≥-.24, p≤.05). However, associations for the first VLF component were positive (r≥.28, p≤.05). While patients´ medication use was associated with lower CBFV variability, comorbid depression and anxiety disorders were unrelated to variability. Conclusions: Lower CBFV variability in the LF and HF ranges were observed in FMS, suggesting impaired coordination of cerebral regulatory systems. CBFV variability was differentially associated with clinical variables as a function of time-scale, with short-term variability being related to better clinical outcomes. CBFV variability analysis may be a promising tool to characterize FMS pathology and it impact on facets of HRQoL.Ítem Variability in cerebral blood flow velocity at rest and during mental stress in healthy individuals: Associations with cardiovascular parameters and cognitive performance.(Elsevier, 2018) Montoro, Casandra I.; Duschek, Stefan; Reyes del Paso, Gustavo A.This study analyzed variability in cerebral blood flow velocity (CBFV) and possible underlying physiological mechanisms during rest and a mental arithmetic task. Blood flow velocities were bilaterally recorded by transcranial Doppler sonography in the anterior and middle cerebral arteries of 43 participants. Electrocardiography, continuous blood pressure (BP) and respiratory recordings were additionally obtained. Fast Fourier transformation revealed a spectral profile with two main components in CBFV, one in the very low frequency (VLF, 0.01–0.025 Hz), and the other in the low frequency band (LF, 0.075–0.11 Hz). During the task, CBFV variability decreased. While heart rate variability and respiration had only weak impacts, BP variability was closely associated with CBFV variability. LF CBFV variability correlated negatively with task performance. The findings indicate a connection between peripheral and cerebral hemodynamics, presumably mediated by the passive pressure-flow relationship and neural mechanisms. LF CBFV variability may constitute a suitable marker of mental effort load.